Standing balance assessment and prognosis in low back pain

Executive assessment

Standing balance assessment can describe how a person with low-back pain manages a particular postural task. Its value depends on the task, the measured quantity and the intended decision. Quiet-standing centre-of-pressure measures, timed single-leg stance, directional reaching, response to a perturbation and perceived balance confidence are related but distinct. None can be substituted for the others simply because all are labelled balance.

The strongest practical message is to standardize and preserve the protocol. Direct studies support reproducible measurement of selected force-platform variables under selected conditions, and the Y-Balance Test has excellent agreement between raters scoring the same performances in young adults with chronic low-back pain. However, neither finding establishes a universal balance score, a patient-important change threshold or an individual future-falls probability. Same-session reproducibility and same-performance rater agreement often look more reassuring than the evidence available for repeated patient testing across days. [1‑6]

Reviews disagree about the consistency of abnormal sway. A 2023 meta-analysis found larger sway amplitude in chronic low-back pain, while average sway velocity did not differ clearly; its certainty was low or very low and its prediction intervals allowed substantial variation between settings. Earlier reviews found inconsistent findings, especially in uncomplicated eyes-open stance. These are differences in evidence sets and analysis, not a choice between a universally abnormal and a universally normal balance system. [7‑9]

Actual prospective evidence is materially weaker than the volume of case-control research suggests. A persistent-LBP cohort found that baseline force-platform measures did not distinguish later pain or disability improvers from non-improvers. Occupational cohorts supply some associations with later back symptoms but no externally validated standing-balance risk calculator. Older adults with chronic LBP do experience prospectively recorded falls, yet an informative fall cohort examined hip signs and symptoms as the exposure, not a validated sway threshold. [10‑14]

For rehabtools, a defensible initial product is a transparent assessment record: what the person did, for how long, under which sensory and support conditions, with which symptoms and assistance, and how the current result compares with prior matched testing. Instrumented features can add useful information when their validation matches the device and output. A diagnostic or prognostic claim requires additional evidence. This report concerns assessment design and evidence interpretation, not individualized treatment advice.

Scope and search approach

Adults with chronic nonspecific or primary low-back pain are the principal population. Recurrent pain, current flares, subacute symptoms and chronic persistent symptoms remain distinct where study definitions allow. Radicular symptoms, objective neurological signs, spinal stenosis, lumbar surgery and specific structural disease are separate applicability categories. A chronic-LBP sample is not necessarily a nonspecific-LBP sample, and a sample tested during symptom remission may differ substantially from people seeking care during a severe episode.

Three native PubMed streams covering measurement, prognosis and protocol or technology returned 183, 579 and 710 records. Official NCBI reconciliation recovered all records despite duplicate and omitted records in connector pagination. Corresponding Scopus streams returned 315, 1,042 and 1,088 unique records. Across overlapping streams there were 1,136 PubMed IDs and 1,817 Scopus IDs. These are retrieval counts, not counts of eligible studies, and databases cannot be summed without cross-database deduplication.

What the assessment actually measures

Quiet standing

A force platform measures ground-reaction forces and moments from which the centre of pressure, or CoP, is calculated. The resulting trajectory reflects the combined control of the whole body over the support surface. It is not a direct recording of lumbar instability, a measure of the centre of mass, or a test of one particular muscle. Anteroposterior and mediolateral displacement, path length, velocity, area, spectral features and nonlinear regularity describe different properties of that trajectory.

These variables should not be assembled into one unnamed sway score. Path length depends strongly on acquisition duration and processing; velocity introduces a time denominator; an area estimator requires its own definition. A 90% ellipse and a 95% ellipse are not interchangeable, and the same label can conceal different computation. Units and coordinate conventions should be retained. A displacement statistic describing the position of the mean CoP relative to an origin is not the same as the amplitude of fluctuations around that mean.

Greater movement is not intrinsically worse. A person may use small excursions through stiffening, larger excursions through exploratory control, or more frequent weight shifts to manage discomfort. The task's demands and stability boundaries determine whether a strategy is effective. Quiet stance on a firm surface may be too undemanding to reveal a limitation that appears during reaching, visual occlusion or a perturbation. Conversely, adding difficulty changes the construct and can make the task less safe or less reproducible. [7‑9]

Timed stance and clinical scales

Timed single-leg stance measures the ability to maintain a specified position until a defined endpoint, up to a time cap. It does not quantify all movement occurring before that endpoint. Two people can each complete 30 seconds while using quite different trunk, hip and ankle strategies. A time cap also produces a ceiling: repeated maximum scores provide little evidence that no physiological change occurred.

Specify the stance leg, eyes, footwear, arm position, free-leg position, permitted movement, support, timing onset, termination criteria, practice attempts and whether the best or mean trial is scored. A self-selected leg held for up to 60 seconds, as used in the large Piva cohort, is a different procedure from an eyes-closed single-leg test or bilateral testing with a different cap. Do not borrow healthy-adult or neurological cutoffs without identifying their source population and the mismatch. [1, 15]

Clinical ratings of pelvic or trunk position add another construct. Penney and colleagues found weaker gluteus medius muscles in a small nonspecific-CLBP group, yet a positive clinical single-leg stance test did not identify that weakness or distinguish the pain group. A visibly asymmetric stance therefore does not establish a particular muscle deficit. Direct dynamometry and symptom assessment may answer a different, useful question. [16]

Berg, BESTest variants, functional reach and staged stance batteries can be reasonable choices when a person's broader mobility or falls presentation warrants them. Their use in a clinic should not be described as LBP-specific validation unless that exact evidence is available. The current appraisal does not establish a universal nonspecific-LBP minimal important change for these scales. A composite total can also conceal opposing changes across tasks. Preserve component scores and the reason for selecting the battery rather than importing a generic fall-risk band.

Reaching and perturbed balance

The Y-Balance Test involves single-leg support and directional reaching. Its output incorporates balance, lower-limb mobility, strength, motor planning and willingness to approach the stability boundary. A poorer score is not a pure lumbar control deficit. Its advantage is a relatively practical, direction-specific task that may reveal limitations missed by easy quiet standing. [5]

Moving-platform, sudden-force-release and sensory-organization procedures ask how a person responds when conditions change. Latency, scaling and coordination of a recovery response differ from the variability of unperturbed stance. The original Radebold experiment combined unstable sitting with trunk responses to sudden force release and found a concurrent relationship between balance and response timing. This supports a mechanistic question, but it does not identify the cause of pain or establish a treatment-selection rule. [17]

Unstable sitting is especially important to label separately. Reducing the lower limbs' role can help study trunk control, but the task's results are not standing-balance measurements. The 16-patient reproducibility study used blindfolded wobble-board sitting with different foot-lift and arm-movement conditions, multiple 40-second trials and a short retest. Its protocol and mild recurrent/persistent sample constrain transfer to everyday standing. [18]

Table 1 Select the task for the balance question

Practical synthesis from the appraised studies. Task selection should follow the clinical question and safety assessment.

Population and sensory context

Why the reviews reach different conclusions

Koch and Hänsel reviewed nonspecific-LBP studies of unperturbed bipedal stance and found inconsistent individual CoP findings, with a tendency toward greater differences when the task became more demanding. Their synthesis included differing symptom definitions and some experimentally induced standing pain. Mazaheri and colleagues included specific as well as nonspecific LBP and found that more complex sensory manipulation did not systematically increase the proportion of studies reporting differences. The populations and synthesis methods are therefore not identical. [7, 9]

Park and colleagues pooled several amplitude-related CoP variables under body sway. Across 15 studies and 623 participants, the pooled standardized difference was 0.77, with a 95% confidence interval of 0.50 to 1.04. Heterogeneity was high, and the prediction interval ranged from −0.29 to 1.82. The body-sway-velocity estimate was 0.21, with a confidence interval from −0.03 to 0.45. The authors rated amplitude evidence very low certainty and overall velocity evidence low certainty. These findings support an average amplitude tendency while cautioning against a common abnormal boundary. [8]

A pooled standardized difference is not a clinical threshold. It does not specify the expected value on a particular platform, identify an individual with pain, quantify the probability of falling, or indicate how much improvement a patient would value. Nor does the larger mean difference under visual occlusion prove that every patient is unusually dependent on vision. A task can discriminate groups while remaining too noisy for individual longitudinal monitoring.

Pain state and coexisting conditions

Current pain, symptom distribution, age, lower-limb pain, vestibular or neurological conditions, vision, fatigue and medication can influence performance. In an older adult, an abnormal result may reflect several contributors rather than low-back pain alone. Record these features rather than attributing all instability to the back.

Research exclusions matter. The Y-Balance study excluded signs of nerve-root compression, previous lumbar or lower-limb surgery, other lower-limb pain, balance disorders, walking aids and participants receiving current medical care. Its young sample had relatively low disability. The catastrophizing and CoP study excluded several medical and psychological comorbidities and people with BMI above 30. Such samples help isolate research questions but do not represent everyone attending rehabilitation. [5, 19]

Fear and confidence belong in interpretation without becoming explanations imposed on the patient. In the 68-patient catastrophizing study, selected psychological, age and muscle-thickness-change measures explained approximately one quarter of contemporaneous eyes-closed sway-area variation. The ultrasound task was performed separately from balance. The study did not demonstrate that catastrophizing caused poor balance or that changing it would reduce falls. A broader review similarly supports examining relationships between fear-related factors and performance without treating them as evidence of deliberate underperformance. [19, 20]

Reliability and agreement

Relative reliability is only one part of repeatability

An intraclass correlation coefficient describes relative ordering in a particular sample. It can be high when people differ greatly from one another despite substantial within-person error. Its model matters: single versus averaged measurements, consistency versus absolute agreement, and same versus different assessors answer different questions. Confidence intervals should accompany the estimate, especially in samples of 15 or 20 participants.

The standard error of measurement describes error in a single measurement under specified assumptions. A minimal detectable change or smallest detectable change typically describes a difference unlikely to arise from random error at a stated confidence level. For independent measurements with equal error and no systematic bias, the familiar 95% calculation is 1.96 × square root of 2 × SEM. This calculation does not convert an unreliable task into a reliable one, resolve learning effects, or establish patient importance. When variability is proportional to the score, log-scale or ratio-based agreement may be more appropriate than a constant additive threshold.

Maribo's 49-patient same-session study found that trace length and velocity were more reproducible than sway area, the eyes-open/eyes-closed Romberg ratio and single-leg stance. This is useful variable-selection evidence. It does not supply an interchangeable error threshold for a different device or a test repeated weeks later. The author thesis also presents additional analyses beyond the published study; those are labelled as thesis evidence rather than silently promoted to final-paper findings. [1]

An earlier direct clinical study by Maribo and colleagues offers useful protocol-specific single-leg-stance precision. Forty-eight people with CLBP repeated testing after 20 minutes. Barefoot, arms-crossed testing used the best of two trials on each leg, then analysed the poorer leg. Eyes-open performance had a substantial ceiling. For eyes-closed testing, the reported intra-observer SEM was 2.48 seconds and MDC 6.88 seconds; interobserver values were 1.42 and 3.95 seconds. The latter comparison involved repeated patient performances, unlike Y-Balance scoring of the same performance. These small-sample estimates support a standardized clinical procedure but not a day-to-day or patient-important cutoff. One long performer materially affected the interobserver ICC, demonstrating why the point estimate should not stand alone. [21]

Learning can imitate improvement

Leitner's SMART EquiTest study is a useful warning against equating repeated-test improvement with treatment response. Among chronic-LBP patients and controls, sensory-organization and adaptation measures improved within sessions; demanding sensory-organization conditions also improved at a later assessment in untreated patients. Reported pain and test-related feelings did not explain those learning effects. The finding supports adequate familiarization and a cautious interpretation of early gains. [2]

Biodex reliability depends on platform level, visual condition and cognitive task. In Sherafat's 15-patient study, intersession ICC ranges differed by index and condition; these are dynamic-platform results rather than a universal CoP reliability estimate. A later 30-patient double-leg study manipulating vision, vibration and auditory Stroop tasks found mean velocity more consistently reproducible than area. Increasing task difficulty may sometimes improve between-person discrimination but does not guarantee smaller absolute measurement error. [3, 4]

The newer HUMAC report is promising for a defined athletic application: 15 young athletes with CLBP repeated squat and limits-of-stability tasks a week apart, with ICCs between 0.84 and 0.98. Its original numerical table is now available, but the SEM/MDC computation remains unresolved; individual thresholds are withheld. The tested movements differ from quiet stance. An app should not convert the reported ICC range into a general LBP balance change rule. [22]

Excellent rater agreement is not excellent patient retesting

The Y-Balance study illustrates the distinction particularly clearly. Two raters independently read the same session's reaches, and ICCs were 0.99 to 1.00. Participants performed six practice reaches in each direction on each leg; three measured reaches were averaged and normalized to leg length. The finding supports repeatable scoring of that protocol. It does not include day-to-day changes in the patient's performance, and it does not establish a between-day MDC or patient-important improvement. [5]

The protocol's burden is greater than a single reach in three directions. Practice on both legs, repeated invalid trials and rest must be included in time estimates. The main group comparison used the controls' dominant leg and the patients' involved side, with a specified rule for bilateral pain. Substituting the best reach for the mean, restricting arm use, measuring leg length differently or testing in shoes changes the implementation. Software should specify which version it supports rather than display a familiar test name while changing its score.

The Kinematic Steadiness Index provides another warning about statistical labels. Its recurrent-LBP report evaluated standing time and a video-motion-capture index across one week, but the accessible abstract prominently reports Cronbach alpha. Those values must not be reprinted as ICCs or interpreted as agreement in seconds. The index also represents more than ordinary stopwatch stance duration. [6]

Table 2 Direct measurement findings and their limits

SEM and MDC describe protocol-specific error; patient importance requires a separate anchor.

Change and patient importance

A change in balance can be detectable, relevant to an individual goal, both, or neither. Measurement error is estimated from repeated stable testing. Responsiveness concerns whether change in the measure reflects change in its intended construct. Minimal important change requires a relevant external interpretation of importance, with a credible anchor relationship and uncertainty. A statistically significant pre–post change supplies none of these automatically.

The Maribo longitudinal validity study found poor associations of CoP with pain, fear and physical function, and no useful separation of baseline CoP values between clinically improved and unimproved groups at follow-up. Pain and disability are not gold standards for balance, so this does not prove that the platform measures no valid balance construct. It does challenge using its score as a substitute for pain recovery or overall functioning. The paper's body analysed 96 people, whereas its abstract reports 97; the body denominator is used here. [10]

In the wobble-chair intervention study, some nonlinear changes were associated with changes in pain and disability. However, similar changes in healthy controls tested without treatment suggested learning, and the reliability comparison was based on the healthy group. This is not direct symptomatic responsiveness validation for standing balance. A useful treatment-outcome study should separate measurement learning, recovery, intervention effects and patient-important change. [23]

No universally applicable patient-anchored MIC for a quiet-standing CoP variable, timed single-leg stance or Y-Balance score in nonspecific CLBP was established in this appraisal. That statement is an evidence boundary, not proof that no such study exists. It means the practical tool should show the observed change and its applicable error information, while keeping the patient's own goal and reported experience visible. It should not label an arbitrary percentage improvement clinically meaningful.

Prognosis and falls

Future symptoms differ from current classification

The occupational cohort of Takala and Viikari-Juntura followed 307 initially nonsymptomatic workers and 123 workers with previous LBP separately for two years. Some lower balance and functional performances were associated with later symptoms, consultations or sick leave, but distributions overlapped widely. This is genuine temporal evidence, yet it does not yield a portable probability model for a person with chronic nonspecific LBP. Full model details, calibration and external validation were not established from accessible original material. [11]

Strøyer and Jensen assessed 327 workers over 30 months and did not find an association between measured balance and an increase in LBP intensity. That occupational endpoint differs from future falls and from recovery after treatment. The longitudinal Maribo cohort also used later pain and back-specific function, rather than falls, and employed response-group comparisons rather than a fully developed adjusted prediction model. These studies should not be combined into a single claim that balance either predicts all outcomes or predicts none. [10, 14]

The 2025 review of physical prognostic factors found heterogeneous endpoints, substantial risk of bias and limited high-quality evidence. Its methods specifically excluded motion-capture gait analyses using force plates or three-dimensional video; this should not be misread as excluding every force-platform balance study. The review is not an exhaustive appraisal of instrumented balance, and original studies remain necessary for a particular balance claim. Its broad caution strengthens the case for a clearly specified outcome and follow-up interval. [24]

Actual falls require actual fall ascertainment

In the older-adult chronic-LBP cohort examining hip OA signs and symptoms, monthly calendars and follow-up calls recorded 219 falls among 89 of 210 analysed participants over a year. Fifty participants had multiple falls. Hip impairment burden remained associated with fall counts after adjustment for age, sex, BMI, anxiolytic use, balance confidence, LBP-related disability and prior falls. The reported count-model ratio was 1.23 per burden point, with a 95% confidence interval of 1.09 to 1.38. This ratio concerns fall counts under the fitted model; it should not be converted into a 23-percentage-point increase in the probability of any fall. [12]

The study supplies clinically relevant prospective evidence but does not validate a standing-balance cutoff. Hip signs and symptoms were the main exposure; balance confidence was a covariate. Forty of 250 enrolled participants were not in the final analysis, including two removed fall-count outliers, and excluded participants had worse pain and disability. With 50 multiple-fall outcomes and several predictors, the secondary binary model also warrants caution. No external risk calibration or demonstrated benefit from using the model to make decisions was established. [12]

The LOHAS study similarly links baseline LBP-related disability to later falls, but its exposure is a questionnaire. It cannot be cited as proof that measured CoP or single-leg standing predicts falls. These distinctions are important when an assessment interface presents a red or green risk label: evidence that pain-related disability is associated with falls is not enough to justify that label from a camera-derived sway value. [13]

For prognostic use, a future validation study needs prespecified predictors, a meaningful clinical endpoint, prospective event collection, transparent missing-data handling, adequate event numbers and internal validation that repeats all feature selection. It should demonstrate external discrimination and calibration, incremental information beyond age, prior falls and established clinical factors, and whether acting on the estimate improves decisions. No standalone nonspecific-LBP standing-balance algorithm meeting that sequence was established here.

Table 3 Temporal evidence is outcome specific

Concurrent differences and models explaining a current score are not future-outcome prediction.

Technology and implementation

Devices measure different physical quantities

An IMU on the lumbar region measures segment acceleration or angular motion, while a force platform estimates CoP. Even when derived outputs share names such as path or area, they need not represent the same quantity. In the direct study of 39 CLBP participants and 39 controls, lumbar IMU measures showed only weak-to-moderate correlations with force-platform outputs, and sternum findings were less consistent. Correlation alone does not support replacing one with the other or using the platform's error threshold for the sensor. [25]

Video can support timing, support-contact detection and visible movement description. Claims about small sway amplitudes require validation against an appropriate reference, with attention to camera geometry, occlusion, image rate, clothing, keypoint jitter and filtering. A marker-based standing-angle biomarker in Moissenet's 72-variable study is not CoP and does not validate an ordinary phone camera's balance estimate. The published supplementary protocols and numerical property workbook are useful precisely because they make the output-specific boundaries visible. [26]

A current-state classifier is also not a prognostic model. A model trained to distinguish selected pain and control groups may learn symptom severity, age, task pace or recruitment characteristics. Participant-independent testing, realistic case mixes and external validation are required even for discrimination; later clinical-outcome prediction is an additional task.

Feasibility is part of validity in practice

Piva's large supervised chronic-LBP cohort did not complete every test in every participant. Bilateral standing balance was not done in 3.9% and single-leg balance in 8.9% of the 1,006-person feasibility denominator. Reported average procedure times included instructions, setup, execution and recording: approximately 197 seconds for bilateral standing and 74 seconds for single-leg standing. These are workflow observations, not universal time requirements or evidence of unsupervised home safety. [15]

A usable system should distinguish a task not attempted because of screening, refusal, inability to understand instructions, pain, fatigue, loss of balance and technical failure. Do not replace all such cases with zero seconds or delete them as missing. Completion rates and safety context should be reported alongside numerical scores. People with more severe symptoms or comorbidities are often precisely those lost when only complete records are analysed.

For challenging standing tests, the testing environment and assistance arrangements matter. The clinician should determine whether the task is appropriate and whether guarding or a support surface is required. Eyes-closed foam or unexpected perturbation testing should not be introduced merely to make a home test more discriminating. Research exclusion criteria do not function as a complete remote safety protocol.

Table 4 A defensible balance tool

These recommendations are implementation principles, not a validated combined score.

Practical recommendations for rehabtools

Start with a clearly named task and a small number of interpretable outputs. For timed stance, retain raw durations, the cap, leg, assistance and failure reason. For a platform, retain the condition-specific variable, unit, processing version and number of accepted trials. For reaching, preserve direction-specific raw and normalized distances, leg-length measurement and scoring method. Display a source-matched error estimate only when the protocol, population and retest design are sufficiently similar.

Record symptoms at the time of testing and movement-related symptoms during or after it. Show the patient's functional goal separately from the instrumental result. A person can improve in confidence or daily participation without a measurable sway change, and can improve on a practiced balance test without broader benefit.

Do not infer a pain mechanism, weak muscle, recurrence risk or falls probability from a single balance feature. A more advanced module should first establish repeated-measurement properties in the intended users and deployment setting. Patient-important change and prospective prognostic utility should then be investigated as distinct claims, with prospective registration of that future research rather than a retrospective claim that this narrative review was registered.

Limitations and conclusion

The evidence is uneven. Several influential originals remain abstract-only or have inaccessible numerical tables. Complete article text does not guarantee access to figures, supplements or exact device settings. Small samples, narrow inclusion criteria, variable ICC models, practice effects and multiple candidate outcomes make apparently consistent high-reliability claims less uniform than they first appear. The search retrieved broad, reconciled evidence sets but did not independently screen every record twice.

Balance assessment is nevertheless useful when its meaning stays specific. Clinical stance and reaching tests can document task performance, while platforms and sensors can characterize selected aspects of postural control. The most defensible clinical and technical interpretation is a protocol-matched description of performance and change, combined with symptoms and broader function. Current evidence does not justify treating sway as a diagnostic signature or a standalone forecast of falls, disability or recurrence.

Primary study characteristics

The study profiles preserve the population, design, protocol, measurement findings, change interpretation, later outcomes and limitations for each appraised original study. A source can be useful for one question while remaining insufficient for another. Contextual and mixed-population studies are explicitly identified, and related publications are not assumed to represent independent cohorts.

Maribo 2011

Study and population [1] Direct measurement study. 49 LBP; persistent symptoms; broader phenotype than pure nonspecific CLBP

Protocol Portable force platform and one-leg stand; repeated within session

Measurement and change Trace length / velocity more reproducible than area, Romberg ratio or one-leg time; ICC alone insufficient. No patient-anchored MIC

Later outcomes and interpretation No later clinical endpoint. Same-session evidence; exact final-paper numeric error table unavailable; author thesis extra analyses kept separate

Source examined PMID 21616669; thesis printed pp 23–29. Original abstract plus author thesis methods and results; thesis contains additional unpublished analyses and is not treated as identical to final paper

Maribo 2012

Study and population [10] Longitudinal validity / response grouping. 96 analysed persistent-LBP patients; 139 tested; 39 lost; duration 9 weeks–30 years; includes radiating symptoms

Protocol HurLabs BT 4; fixed foot position; EO / EC; follow-up median 14.5 weeks

Measurement and change Poor associations with pain, fear and function; no baseline CoP differences between ≥30% improvers and others. Clinical outcome change defined using 30%; no CoP MIC

Later outcomes and interpretation Actual later pain / function, but simple response-group comparison rather than externally validated adjusted risk model. Abstract says 97; body 96. 28.1% loss; pain / function are not criterion gold standards for balance

Source examined PMC3296857 Methods/Results/Tables 1–4; DOI final-paper body. Original PMC methods and results accessible through indexed full text; author thesis additionally consulted; abstract n 97 conflicts with body analytic n 96

Leitner 2009

Study and population [2] Measurement reliability and case-control. 32 CLBP / 19 controls; 22 untreated patients retested

Protocol SMART EquiTest SOT / MCT / ADT; repeat 2–3 weeks

Measurement and change Learning in SOT / ADT within session and demanding SOT conditions between sessions. No anchor-based balance MIC

Later outcomes and interpretation No clinical prognosis. Treatment-free improvement can imitate recovery; original abstract only

Source examined PMID 18023594. Original abstract or metadata only; no original full-text numerical table validation

Sherafat 2013

Study and population [3] Direct instrumented reliability. 15 CLBP / 15 matched controls

Protocol Biodex levels 3 / 5; EO / EC; with / without auditory Stroop

Measurement and change Patient intersession ICC ranges AP .60–.88, ML .64–.94, overall .63–.91. Original SEM table unavailable; no MIC

Later outcomes and interpretation No future clinical endpoint. Small sample, variable-specific / condition-specific; instrument indices are not quiet CoP sway

Source examined PMID 23499146. Original abstract or metadata only; no original full-text numerical table validation

Karimi Ghasem Abad 2021

Study and population [4] Direct between-session measurement. 30 nonspecific CLBP

Protocol Eight double-leg conditions; eyes, vibration and auditory Stroop manipulated

Measurement and change Range and mean velocity more reproducible than area; area high ICC only one condition. No verified MIC; precise error tables unavailable

Later outcomes and interpretation No future endpoint. Cognitive accuracy and reaction time need parallel reporting; abstract only

Source examined PMID 33992286. Original abstract or metadata only; no original full-text numerical table validation

Alshehre 2021

Study and population [5] Inter-rater reliability and known-groups comparison. 15 CLBP / 15 controls; 21–38 years; no radicular signs, surgery, aid or active medical care

Protocol Barefoot; six practice reaches per direction on each leg; three measured reaches averaged and normalized to leg length. Main group comparison used dominant control leg and involved CLBP side.

Measurement and change Same-performance ICC(2, k) .99–1.00; lower CLBP reaches. No between-day error or patient MIC

Later outcomes and interpretation Current group difference, not falls or recurrence. Two raters score one session; mean versus maximum protocol matters; lower-limb ROM / strength not measured

Source examined Complete body Methods and Results Tables 1–3. Complete article text; figures and supplementary objects require separate checks

Sung 2018

Study and population [6] Direct kinematic test-retest. 66 recurrent LBP

Protocol One-leg standing video motion capture; 1-week interval; Kinematic Steadiness Index

Measurement and change Standing time and KSI show reliability; abstract reports Cronbach alpha .84 / .89, not verified ICC values. No verified patient MIC

Later outcomes and interpretation No clinical prognosis. Do not relabel Cronbach alpha as ICC; index and ordinary timed stance differ

Source examined PMID 28980075. Original abstract or metadata only; no original full-text numerical table validation

Telles 2022

Study and population [25] Concurrent instrument comparison. 39 CLBP / 39 controls

Protocol Lumbar / sternal IMUs versus force plate during quiet standing

Measurement and change Patient lumbar rs .42–.59 for PATH / RMS / AREA; weak sternum PATH correlation. No change agreement / MIC

Later outcomes and interpretation No future endpoint. Correlation across different quantities is not interchangeability; original abstract only

Source examined PMID 35243965. Original abstract or metadata only; no original full-text numerical table validation

Shahvarpour 2018

Study and population [23] Treatment-response and healthy reliability context. LBP treatment group and healthy controls

Protocol Wobble-chair kinematics before / after 8 weeks; healthy group repeated without treatment

Measurement and change Reliability derived from healthy controls; some nonlinear change–change associations. Similar changes in untreated healthy participants suggest learning

Later outcomes and interpretation Change–change correlation, not baseline clinical prediction. Unstable sitting distinct from standing; no symptomatic error estimate transferred

Source examined PMID 29448220. Original abstract or metadata only; no original full-text numerical table validation

Van Daele 2007

Study and population [18] Direct same-session reproducibility. 16 recurrent / persistent LBP; pain mean 17.6 / 100; BMI≤30; no neurologic symptoms

Protocol Blindfolded unstable sitting; 4 conditions; 3×40 s trials; 10-min retest

Measurement and change Force plate and kinematic outputs differ in reproducibility. No longitudinal responsiveness or MIC

Later outcomes and interpretation No future endpoint. Complex supported task and mild sample; not a standing test; small n

Source examined PMC1888688 Methods/Results. Complete article text; figures and supplementary objects require separate checks

Schilaty 2023

Study and population [27] Concurrent group comparison. 18 CLBP / 15 controls

Protocol IMU gait / balance and dynamometer trunk sensorimotor battery

Measurement and change Physical / psychological associations and group comparisons. No protocol-specific MIC established

Later outcomes and interpretation No future outcome. Small case-control study; sensor results and laboratory force / power not phone-derived strength

Source examined PMID 37245281; original abstract. Original abstract or metadata only; no original full-text numerical table validation

Zhang 2020

Study and population [19] Concurrent association with reliability substudy. 68 NSCLBP / 40 controls; 18–65 y; restrictive comorbidity and medication criteria

Protocol Quiet CoP EO / EC; TrA ultrasound during separate drawing-in manoeuvre

Measurement and change Area difference only EC; ICC(3, 1) .712–.748 across CoP outputs; regression R²≈.25. No longitudinal responsiveness / MIC

Later outcomes and interpretation Current sway explained, not subsequent falls. Outcome selected after group comparison; ultrasound not during balance; no causal mediation

Source examined PMC complete body Results 3.2–3.5/Limitations. Complete article text; figures and supplementary objects require separate checks

Takala 2000

Study and population [11] Prospective occupational cohort. 307 nonsymptomatic and 123 prior-LBP workers; two separate cohorts

Protocol Baseline strength / endurance / force-platform balance; 2-year pain, consultations and sick leave

Measurement and change Not a measurement-error study. No MIC

Later outcomes and interpretation Selected associations with future pain; workload / sex / age / anthropometrics considered. Large overlap; no calibrated external model; do not pool prevention and prior-LBP cohorts

Source examined PMID 10954645 original abstract; review tables secondary only. Original abstract or metadata only; no original full-text numerical table validation

Knox 2021

Study and population [12] Adjusted prospective fall association. 250 older CLBP enrolled; 210 analysed; 60–85 y; 89 fallers / 219 falls; 50 multiple fallers

Protocol Hip signs / symptoms burden; monthly calendars and telephone follow-up 12 months

Measurement and change No measured-standing-test validation. Not applicable

Later outcomes and interpretation Per burden point fall-count ratio 1.23(CI 1.09–1.38); multiple-fall OR 1.41(CI 1.01–1.95); 7 covariates. Exposure hip burden, not CoP; 38 incomplete plus 2 outliers removed; excluded group had worse pain / disability; no external prediction / calibration

Source examined PMC complete body Methods/Data analysis/Results Table 2. Complete article text; figures and supplementary objects require separate checks

Kimachi 2019

Study and population [13] Prospective association with adjacent exposure. 2738 enrolled / 1358 analysed older residents

Protocol RMDQ-defined LBP disability at baseline; 1-year falls

Measurement and change Questionnaire exposure, not a balance test. Not applicable

Later outcomes and interpretation Adjusted subsequent-fall associations. Analytic attrition; no measured CoP / SLS predictor; original abstract only

Source examined PMID 30856262. Original abstract or metadata only; no original full-text numerical table validation

Piva 2025

Study and population [15] Large descriptive feasibility. 1007 enrolled chronic-LBP cohort; 1006 feasibility denominator; prior surgery / comorbidities included

Protocol Supervised extensive battery; standing, hip HHD, dynamometry / stairs, active sit-up

Measurement and change Balance not done 3.9% bilateral / 8.9% single-leg; hip HHD 21.3–25.8%; active sit-up 26.8%. No reliability or MIC validation

Later outcomes and interpretation No prognosis. Safety-screening, refusal and protocol changes matter; quadriceps frame failed, replacement tasks not equivalent; descriptive means not norms

Source examined Complete body Tables 1/3/4 and protocol-change section. Complete article text; figures and supplementary objects require separate checks

Moissenet 2023

Study and population [26] Reliability and current group discrimination. 30 NSCLBP / 30 controls; 24 patients retested

Protocol 72 movement biomarkers; marker-based laboratory tasks

Measurement and change Standing-angle feature distinct from CoP; measure-specific reliability required. No patient MIC

Later outcomes and interpretation No future outcome. No generic video balance validation or validated composite; multiple-feature selection

Source examined Complete XML; supplementary workbooks 3 and 4. Complete original article and supplementary measurement properties workbook and task protocols

Ansari 2026

Study and population [22] Direct one-week instrument reliability. 15 athletes with CLBP; 18–30 years

Protocol HUMAC CoP indices during squat and limits of stability

Measurement and change ICC(2, 1) .84–.98; SEM / MDC assessed; abstract no systematic bias. Original table recovered, but SEM/MDC computation unresolved; no individual threshold implemented; no MIC

Later outcomes and interpretation No falls or functional prognosis. Online 2025 / issue 2026; athletic restricted sample; dynamic tasks not quiet stance

Source examined PMID 40376933 original abstract. Original numerical table now recovered; SEM/MDC computation remains unresolved; published online May 2025, journal issue 2026

Penney 2014

Study and population [16] Concurrent clinical-test validity. 21 nonspecific CLBP / 22 controls

Protocol Clinical single-leg stance rating; hip HHD / EMG

Measurement and change CLBP group weaker; positive clinical SLS did not distinguish weakness or CLBP. No MIC

Later outcomes and interpretation No later endpoint. Clinical sign not equivalent to timed stance or gluteal force; abstract only

Source examined PMID 24992020. Original abstract or metadata only; no original full-text numerical table validation

Radebold 2001

Study and population [17] Mechanistic concurrent comparison. 16 chronic idiopathic LBP / 14 controls

Protocol Unstable sitting plus sudden resisted-force release; 12-muscle EMG

Measurement and change Poorer challenging sitting balance / delayed responses; adjusted concurrent R² reported. No MIC

Later outcomes and interpretation No future clinical outcome. Mechanistic association does not prove cause, treatment indication or future injury

Source examined PMID 11295888 original abstract. Original abstract or metadata only; no original full-text numerical table validation

Strøyer 2008

Study and population [14] Prospective occupational association. 327 workers; 271 women; review reports 113 missing at 30 months

Protocol Extension / flexion endurance, balance; >2 / 10 increase in prior-year pain

Measurement and change Not measurement validation. No patient-important endurance threshold

Later outcomes and interpretation Middle endurance category OR 2.7, P=.034; low category OR 2.4, P=.076; overall P=.067; measured balance not associated. Nonmonotonic result; incomplete full-text adjustment / events; no deployable risk rule

Source examined PMID 18317201 abstract; Rashed table secondary attrition. Original abstract or metadata only; no original full-text numerical table validation

Maribo 2009

Study and population [21] Direct intra-observer and interobserver reliability. 48 CLBP lasting more than six months; referred for exercise

Protocol Barefoot, arms crossed, lifted foot behind stance leg; best of two each leg, poorer leg analysed; EO cap 60 s / EC cap 30 s; repeat 20 min

Measurement and change EC intra n 20: ICC 0.86, SEM 2.48 s, MDC 6.88 s; inter n 27: ICC 0.91, SEM 1.42 s, MDC 3.95 s. Reported MDC from short-interval repeated performance, not MIC

Later outcomes and interpretation No later falls or recovery endpoint. EO ceiling 81% intra / 48% inter; dropping long EC performer reduced inter ICC 0.91 to 0.70; no between-day evidence

Source examined Original PDF Tables 1 and 2, printed pages 174–175; independently inspected. Original publisher PDF inspected independently including Tables 1 and 2 on printed pages 174–175; direct source-specific clinical error estimates

Search methods and source access

Table 5 Search retrieval and reconciliation

Across the three overlapping slices: 1136 unique PubMed IDs and 1817 unique Scopus IDs. These are database records, not unique eligible or appraised studies.

Exact executed native queries

Measurement PubMed

("Low Back Pain"[MeSH Terms] OR "low back pain"[Title/Abstract] OR "low-back pain"[Title/Abstract] OR lumbago[Title/Abstract] OR "lumbar pain"[Title/Abstract]) AND ("Postural Balance"[MeSH Terms] OR (balance[Title/Abstract] OR "postural control"[Title/Abstract] OR "postural sway"[Title/Abstract] OR "postural stability"[Title/Abstract] OR "single leg"[Title/Abstract] OR "single-leg"[Title/Abstract] OR "one leg"[Title/Abstract] OR "one-leg"[Title/Abstract] OR "center of pressure"[Title/Abstract] OR "centre of pressure"[Title/Abstract] OR posturograph*[Title/Abstract] OR "functional reach"[Title/Abstract] OR "step test"[Title/Abstract] OR BESTest[Title/Abstract] OR Berg[Title/Abstract] OR "sensory organization"[Title/Abstract])) AND (reliab*[Title/Abstract] OR valid*[Title/Abstract] OR reproducib*[Title/Abstract] OR psychometr*[Title/Abstract] OR clinimetr*[Title/Abstract] OR agreement[Title/Abstract] OR "measurement error"[Title/Abstract] OR "standard error"[Title/Abstract] OR "minimal detectable"[Title/Abstract] OR "minimum detectable"[Title/Abstract] OR "smallest detectable"[Title/Abstract] OR "minimal important"[Title/Abstract] OR "minimally important"[Title/Abstract] OR "minimum important"[Title/Abstract] OR responsiv*[Title/Abstract] OR interpretabil*[Title/Abstract] OR "floor effect"[Title/Abstract] OR "ceiling effect"[Title/Abstract]) AND ("1800/01/01"[Date - Publication] : "2026/10/02"[Date - Publication])

Measurement Scopus

TITLE-ABS-KEY(("low back pain" OR "low-back pain" OR lumbago OR "lumbar pain") AND (balance OR "postural control" OR "postural sway" OR "postural stability" OR "single leg" OR "single-leg" OR "one leg" OR "one-leg" OR "center of pressure" OR "centre of pressure" OR posturograph* OR "functional reach" OR "step test" OR BESTest OR Berg OR "sensory organization") AND (reliab* OR valid* OR reproducib* OR psychometr* OR clinimetr* OR agreement OR "measurement error" OR "standard error" OR "minimal detectable" OR "minimum detectable" OR "smallest detectable" OR "minimal important" OR "minimally important" OR "minimum important" OR responsiv* OR interpretabil* OR "floor effect" OR "ceiling effect")) AND PUBYEAR BEF 2027

Prognosis PubMed

("Low Back Pain"[MeSH Terms] OR "low back pain"[Title/Abstract] OR "low-back pain"[Title/Abstract] OR lumbago[Title/Abstract] OR "lumbar pain"[Title/Abstract]) AND ("Postural Balance"[MeSH Terms] OR (balance[Title/Abstract] OR "postural control"[Title/Abstract] OR "postural sway"[Title/Abstract] OR "postural stability"[Title/Abstract] OR "single leg"[Title/Abstract] OR "single-leg"[Title/Abstract] OR "one leg"[Title/Abstract] OR "one-leg"[Title/Abstract] OR "center of pressure"[Title/Abstract] OR "centre of pressure"[Title/Abstract] OR posturograph*[Title/Abstract] OR "functional reach"[Title/Abstract] OR "step test"[Title/Abstract] OR BESTest[Title/Abstract] OR Berg[Title/Abstract] OR "sensory organization"[Title/Abstract])) AND (prognos*[Title/Abstract] OR predict*[Title/Abstract] OR longitudinal[Title/Abstract] OR prospective[Title/Abstract] OR cohort[Title/Abstract] OR "follow up"[Title/Abstract] OR "follow-up"[Title/Abstract] OR recovery[Title/Abstract] OR deteriorat*[Title/Abstract] OR fall*[Title/Abstract] OR "natural history"[Title/Abstract] OR "return to work"[Title/Abstract] OR discharge[Title/Abstract] OR "risk factor"[Title/Abstract]) AND ("1800/01/01"[Date - Publication] : "2026/10/02"[Date - Publication])

Prognosis Scopus

TITLE-ABS-KEY(("low back pain" OR "low-back pain" OR lumbago OR "lumbar pain") AND (balance OR "postural control" OR "postural sway" OR "postural stability" OR "single leg" OR "single-leg" OR "one leg" OR "one-leg" OR "center of pressure" OR "centre of pressure" OR posturograph* OR "functional reach" OR "step test" OR BESTest OR Berg OR "sensory organization") AND (prognos* OR predict* OR longitudinal OR prospective OR cohort OR "follow up" OR "follow-up" OR recovery OR deteriorat* OR fall* OR "natural history" OR "return to work" OR discharge OR "risk factor")) AND PUBYEAR BEF 2027

Protocol mechanism technology PubMed

("Low Back Pain"[MeSH Terms] OR "low back pain"[Title/Abstract] OR "low-back pain"[Title/Abstract] OR lumbago[Title/Abstract] OR "lumbar pain"[Title/Abstract]) AND ("Postural Balance"[MeSH Terms] OR (balance[Title/Abstract] OR "postural control"[Title/Abstract] OR "postural sway"[Title/Abstract] OR "postural stability"[Title/Abstract] OR "single leg"[Title/Abstract] OR "single-leg"[Title/Abstract] OR "one leg"[Title/Abstract] OR "one-leg"[Title/Abstract] OR "center of pressure"[Title/Abstract] OR "centre of pressure"[Title/Abstract] OR posturograph*[Title/Abstract] OR "functional reach"[Title/Abstract] OR "step test"[Title/Abstract] OR BESTest[Title/Abstract] OR Berg[Title/Abstract] OR "sensory organization"[Title/Abstract])) AND (protocol[Title/Abstract] OR biomechan*[Title/Abstract] OR kinematic*[Title/Abstract] OR kinetic*[Title/Abstract] OR symmetr*[Title/Abstract] OR asymmetr*[Title/Abstract] OR "weight bearing"[Title/Abstract] OR "weight-bearing"[Title/Abstract] OR "ground reaction"[Title/Abstract] OR "force plate"[Title/Abstract] OR "force platform"[Title/Abstract] OR sensor*[Title/Abstract] OR wearable*[Title/Abstract] OR inertial[Title/Abstract] OR acceleromet*[Title/Abstract] OR markerless[Title/Abstract] OR "motion capture"[Title/Abstract] OR camera[Title/Abstract] OR video[Title/Abstract] OR algorithm[Title/Abstract] OR electromyogra*[Title/Abstract] OR activation[Title/Abstract] OR "sampling frequency"[Title/Abstract] OR "filter cutoff"[Title/Abstract]) AND ("1800/01/01"[Date - Publication] : "2026/10/02"[Date - Publication])

Protocol mechanism technology Scopus

TITLE-ABS-KEY(("low back pain" OR "low-back pain" OR lumbago OR "lumbar pain") AND (balance OR "postural control" OR "postural sway" OR "postural stability" OR "single leg" OR "single-leg" OR "one leg" OR "one-leg" OR "center of pressure" OR "centre of pressure" OR posturograph* OR "functional reach" OR "step test" OR BESTest OR Berg OR "sensory organization") AND (protocol OR biomechan* OR kinematic* OR kinetic* OR symmetr* OR asymmetr* OR "weight bearing" OR "weight-bearing" OR "ground reaction" OR "force plate" OR "force platform" OR sensor* OR wearable* OR inertial OR acceleromet* OR markerless OR "motion capture" OR camera OR video OR algorithm OR electromyogra* OR activation OR "sampling frequency" OR "filter cutoff")) AND PUBYEAR BEF 2027

Coverage reconciliation and source selection

All returned database pages were retrieved through the terminal page. Scopus unique-ID counts matched each provider total. PubMed pages repeatedly returned some records while omitting others; exact-query official NCBI ESearch/EFetch recovered all IDs and records without missing fetches. PubMed BookArticle records were handled where present. Native Scopus queries used publication year before 2027; individual included-source dates were checked against the 2 October cutoff, since issue year alone is not exact date eligibility.

Search slices are overlapping discovery sets. No claim is made that all retrieved records were independently screened. Intensive appraisal prioritized original measurement properties, influential change thresholds, useful clinical protocols, technology validation and prospective clinical outcomes. The earlier low-back-pain landscape search, review references and bounded citation chasing supplemented native queries.

Supplementary source discovery on 2 October 2026 used bounded OpenAlex citation searches: backward references from the 2025 HHD responsiveness paper (10.1186/s12891-025-08325-4), forward citations of Maribo 2012 (10.1007/s00586-011-1981-5), and backward references from Rashed 2025 (10.1371/journal.pone.0335535). Each call had a 100-record cap. Returned counts were HHD responsiveness references: 65; Maribo forward citations: 33; Rashed references: 53. These are discovery calls, not complete or independently screened citation universes. The Maribo 2009 clinical single-leg-stance original was additionally identified and verified during independent source appraisal.

Original full articles were sought through bibliographic services and lawful publisher or repository pages; original abstracts were used when full articles remained unavailable. HHD 2023 was retrieved as an article body; its original repository PDF text supplied Tables 1–4 omitted from that body. The 2025 HHD responsiveness, model, band-test, subacute force/EMG, deadlift, caregiver RFD, Y-Balance, balance review and hip-burden fall-study bodies were retrieved where relevant. Continuations for Park 2023 and Rashed 2025 were obtained through the end of each article.

The attempted machine-readable retrieval of Maribo 2012 did not provide an article. Its indexed original PMC methods and results, original abstract and author thesis were distinguished. Maribo 2009 publisher PDF and HHD 2023 numerical tables were independently checked. Some older subscription originals and exact instrument/error tables remain inaccessible. No original is labelled full text merely because its abstract or metadata was returned.

Cross-domain original supplements available for Moissenet 2023 are the numerical measurement-properties workbook and task protocols. They inform output-specific interpretation; they do not validate every video or sensor implementation. Article-level access is recorded in the primary study profiles and references; unresolved evidence needs are listed below.

Remaining source and validation needs

These gaps limit particular claims rather than preventing the present critical narrative report from being useful.

1. Obtain the final numerical tables and full protocols for Maribo 2011, Sherafat 2013, Ghasem 2021 and Sung 2018. HUMAC’s original numerical table is now available, but SEM/MDC computation remains unresolved; individual thresholds stay withheld.

2. Preserve the direct Maribo 2009 clinical single-leg-stance evidence. Its twenty-minute intra-observer and interobserver results do not supply between-day error, patient importance or prospective falls validation.

3. Retrieve the complete Takala and Strøyer prospective reports before implementing any model. Clarify event counts, missingness, selected predictors and full adjustment; no individual risk equation is provided here.

4. A future LBP-specific longitudinal balance study should separate reliability from learning, establish an appropriate patient-relevant change anchor and prospectively ascertain the clinical endpoint. Improvement in sway, improvement in disability and reduced falls are not synonymous.

5. Validate each intended camera or sensor output against its actual quantity and deployment setting. Correlation between IMU and platform outputs does not demonstrate interchangeability. New instrumented features need between-day symptomatic testing and technical-failure reporting.

For Maribo 2012, source access comprises indexed original PMC methods and results, the original abstract and the separately identified author thesis. The attempted machine-readable article retrieval was unsuccessful.

References

References are numbered in first citation order. Source descriptions identify the material examined and are not study quality ratings. Links identify the original publication or the explicitly named original source version.

1. Maribo T, Stengaard-Pedersen K, Jensen LD, Andersen NT, Schiøttz-Christensen B. Postural balance in low back pain patients: Intra-session reliability of center of pressure on a portable force platform and of the one leg stand test. Gait & posture. 2011;34(2):213-7. DOI 10.1016/j.gaitpost.2011.04.014 Source examined: Original abstract plus author thesis methods and results; thesis contains additional unpublished analyses and is not treated as identical to final paper.

Source note: SRC-007dfd589cb9 Maribo T 2011

2. Leitner C, Mair P, Paul B, Wick F, Mittermaier C, Sycha T, Ebenbichler G. Reliability of posturographic measurements in the assessment of impaired sensorimotor function in chronic low back pain. Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology. 2009;19(3):380-90. DOI 10.1016/j.jelekin.2007.09.007 Source examined: Original abstract or metadata only; no original full-text numerical table validation.

Source note: SRC-eae2fd65beb4 Leitner C 2009

3. Sherafat S, Salavati M, Ebrahimi Takamjani I, Akhbari B, Mohammadirad S, Mazaheri M, Negahban H. Intrasession and intersession reliability of postural control in participants with and without nonspecific low back pain using the Biodex Balance System. Journal of manipulative and physiological therapeutics. 2013;36(2):111-8. DOI 10.1016/j.jmpt.2012.12.005 Source examined: Original abstract or metadata only; no original full-text numerical table validation.

Source note: SRC-c8e618d09266 Sherafat S 2013

4. Karimi Ghasem Abad S, Akhbari B, Salavati M, Talebian Moghaddam S, Saeedi A, Seydi M, Ahangari M, Negahban H. Reliability of postural control during double-leg standing in subjects with nonspecific chronic low back pain: Dual-task paradigm and manipulated visual and somatosensory inputs. Journal of bodywork and movement therapies. 2021;26:49-56. DOI 10.1016/j.jbmt.2020.09.005 Source examined: Original abstract or metadata only; no original full-text numerical table validation.

Source note: SRC-f49a076c4740 Karimi Ghasem Abad S 2021

5. Alshehre Y, Alkhathami K, Brizzolara K, Weber M, Wang-Price S. Reliability and Validity of the Y-balance Test in Young Adults with Chronic Low Back Pain. International journal of sports physical therapy. 2021;16(3):628-635. DOI 10.26603/001c.23430 Source examined: Complete article text; figures and supplementary objects require separate checks.

Source note: SRC-82eb8d9f2904 Alshehre Y 2021

6. Sung PS, Danial P, Lee DC. Reliability of the Kinematic Steadiness Index during one-leg standing in subjects with recurrent low back pain. European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. 2018;27(1):171-179. DOI 10.1007/s00586-017-5314-1 Source examined: Original abstract or metadata only; no original full-text numerical table validation.

Source note: SRC-2274ab91243e Sung PS 2018

7. Koch C, Hänsel F. Non-specific Low Back Pain and Postural Control During Quiet Standing-A Systematic Review. Frontiers in psychology. 2019;10:586. DOI 10.3389/fpsyg.2019.00586 Source examined: Complete article text; figures and supplementary objects require separate checks.

Source note: SRC-9566e04898cc Koch C 2019

8. Park J, Nguyen VQ, Ho RLM, Coombes SA. The effect of chronic low back pain on postural control during quiet standing: A meta-analysis. Scientific reports. 2023;13(1):7928. DOI 10.1038/s41598-023-34692-w Source examined: Complete article text; figures and supplementary objects require separate checks.

Source note: SRC-8fa079762ba2 Park J 2023

9. Mazaheri M, Coenen P, Parnianpour M, Kiers H, van Dieën JH. Low back pain and postural sway during quiet standing with and without sensory manipulation: a systematic review. Gait & posture. 2013;37(1):12-22. DOI 10.1016/j.gaitpost.2012.06.013 Source examined: Original abstract or metadata only; no original full-text numerical table validation.

Source note: SRC-58397b2696d4 Mazaheri M 2013

10. Maribo T, Schiøttz-Christensen B, Jensen LD, Andersen NT, Stengaard-Pedersen K. Postural balance in low back pain patients: criterion-related validity of centre of pressure assessed on a portable force platform. European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. 2012;21(3):425-31. DOI 10.1007/s00586-011-1981-5 Source examined: Original PMC methods and results accessible through indexed full text; author thesis additionally consulted; abstract n 97 conflicts with body analytic n 96.

Source note: SRC-6a155dcc0842 Maribo T 2012

11. Takala EP, Viikari-Juntura E. Do functional tests predict low back pain? Spine. 2000;25(16):2126-32. DOI 10.1097/00007632-200008150-00018 Source examined: Original abstract or metadata only; no original full-text numerical table validation.

Source note: SRC-4835f47d5c38 Takala EP 2000

12. Knox PJ, Coyle PC, Pugliese JM, Pohlig RT, Sions JM, Hicks GE. Hip osteoarthritis signs and symptoms are associated with increased fall risk among community-dwelling older adults with chronic low back pain: a prospective study. Arthritis research & therapy. 2021;23(1):71. DOI 10.1186/s13075-021-02455-5 Source examined: Complete article text; figures and supplementary objects require separate checks.

Source note: SRC-033e0f42ea00 Knox PJ 2021

13. Kimachi K, Kimachi M, Takegami M, Ono R, Yamazaki S, Goto Y, Onishi Y, Sekiguchi M, Otani K, Konno SI, Kikuchi SI, Fukuhara S, Yamamoto Y. Level of Low Back Pain-Related Disability Is Associated with Risk of Subsequent Falls in an Older Population: Locomotive Syndrome and Health Outcomes in Aizu Cohort Study (LOHAS). Pain medicine (Malden, Mass.). 2019;20(12):2377-2384. DOI 10.1093/pm/pny313 Source examined: Original abstract or metadata only; no original full-text numerical table validation.

Source note: SRC-850c6232ad04 Kimachi K 2019

14. Strøyer J, Jensen LD. The role of physical fitness as risk indicator of increased low back pain intensity among people working with physically and mentally disabled persons: a 30-month prospective study. Spine. 2008;33(5):546-54. DOI 10.1097/brs.0b013e3181657cde Source examined: Original abstract or metadata only; no original full-text numerical table validation.

Source note: SRC-bbb45bc8f2fb Stryer J 2008

15. Piva SR, Alfikri Z, Anderst W, Bell KM, Carlesso C, Darwin J, Delitto A, Greco CM, Johnson ME, McKernan GP, McLoughlin R, Patterson CG, Roos RE, Schneider MJ, Smith C, Sowa GA, Vo NV, Zhou L. Feasibility of Physical Exam and Performance-Based Tests in Individuals With Chronic Low Back Pain: A Descriptive Study. JOR spine. 2025;8(3):e70096. DOI 10.1002/jsp2.70096 Source examined: Complete article text; figures and supplementary objects require separate checks.

Source note: SRC-440cc699ea82 Piva SR 2025

16. Penney T, Ploughman M, Austin MW, Behm DG, Byrne JM. Determining the activation of gluteus medius and the validity of the single leg stance test in chronic, nonspecific low back pain. Archives of physical medicine and rehabilitation. 2014;95(10):1969-76. DOI 10.1016/j.apmr.2014.06.009 Source examined: Original abstract or metadata only; no original full-text numerical table validation.

Source note: SRC-d17fd6f66213 Penney T 2014

17. Radebold A, Cholewicki J, Polzhofer GK, Greene HS. Impaired postural control of the lumbar spine is associated with delayed muscle response times in patients with chronic idiopathic low back pain. Spine. 2001;26(7):724-30. DOI 10.1097/00007632-200104010-00004 Source examined: Original abstract or metadata only; no original full-text numerical table validation.

Source note: SRC-70af550936e2 Radebold A 2001

18. Van Daele U, Huyvaert S, Hagman F, Duquet W, Van Gheluwe B, Vaes P. Reproducibility of postural control measurement during unstable sitting in low back pain patients. BMC musculoskeletal disorders. 2007;8:44. DOI 10.1186/1471-2474-8-44 Source examined: Complete article text; figures and supplementary objects require separate checks.

Source note: SRC-d3bd23b24fad Van Daele U 2007

19. Zhang C, Zhang Z, Li Y, Feng C, Meng H, Gao Y, Lo WLA, Wang C. Pain Catastrophizing Is Related to Static Postural Control Impairment in Patients with Nonspecific Chronic Low Back Pain: A Cross-Sectional Study. Pain research & management. 2020;2020:9629526. DOI 10.1155/2020/9629526 Source examined: Complete article text; figures and supplementary objects require separate checks.

Source note: SRC-4fe49270847f Zhang C 2020

20. Matheve T, Janssens L, Goossens N, Danneels L, Willems T, Van Oosterwijck J, De Baets L. The Relationship Between Pain-Related Psychological Factors and Maximal Physical Performance in Low Back Pain: A Systematic Review and Meta-Analysis. The journal of pain. 2022;23(12):2036-2051. DOI 10.1016/j.jpain.2022.08.001 Source examined: Complete article text; figures and supplementary objects require separate checks.

Source note: SRC-4dcdcbbbd059 Matheve T 2022

21. Maribo T, Iversen E, Andersen NT, Stengaard-Pedersen K, Schiøttz-Christensen B. Intra-observer and interobserver reliability of One Leg Stand Test as a measure of postural balance in low back pain patients. International Musculoskeletal Medicine. 2009;31(4):172-177. DOI 10.1179/175361409x12472218841040 Source examined: Original publisher PDF inspected independently including Tables 1 and 2 on printed pages 174–175; direct source-specific clinical error estimates.

Source note: SRC-bf41d6fcee0d Maribo T 2009

22. Ansari S, Sharma S. Steady or Swaying? Assessing the Reliability of the HUMAC Balance System in Athletes With Chronic Low Back Pain. Sports health. 2026;18(3):619-628. DOI 10.1177/19417381251334638 Source examined: Original abstract or metadata only; no original full-text numerical table validation; published online May 2025, journal issue 2026.

Source note: SRC-96b3efb4e0b3 Ansari S 2026

23. Shahvarpour A, Gagnon D, Preuss R, Henry SM, Larivière C. Trunk postural balance and low back pain: Reliability and relationship with clinical changes following a lumbar stabilization exercise program. Gait & posture. 2018;61:375-381. DOI 10.1016/j.gaitpost.2018.02.006 Source examined: Original abstract or metadata only; no original full-text numerical table validation.

Source note: SRC-650e40120bb1 Shahvarpour A 2018

24. Rashed R, Niazigharemakher A, Walton D, Kowalski K, Rushton A. Physical measures of physical functioning as prognostic factors to predict outcomes in low back pain: A systematic review and narrative synthesis. PloS one. 2025;20(10):e0335535. DOI 10.1371/journal.pone.0335535 Source examined: Complete article text; figures and supplementary objects require separate checks.

Source note: SRC-2be3805c8003 Rashed R 2025

25. Telles GF, Ferreira AS, Junior PMP, Lemos T, Bittencourt JV, Nogueira LAC. Concurrent validity of the inertial sensors for assessment of balance control during quiet standing in patients with chronic low back pain and asymptomatic individuals. Journal of medical engineering & technology. 2022;46(5):354-362. DOI 10.1080/03091902.2022.2043947 Source examined: Original abstract or metadata only; no original full-text numerical table validation.

Source note: SRC-99a0b0fd8dcd Telles GF 2022

26. Moissenet F, Armand S, Genevay S. Measurement properties of 72 movement biomarkers aiming to discriminate non‑specific chronic low back pain patients from an asymptomatic population. Scientific reports. 2023;13(1):6483. DOI 10.1038/s41598-023-33504-5 Source examined: Complete original article and supplementary measurement properties workbook and task protocols.

Source note: SRC-de0028260239 Moissenet F 2023

27. Schilaty N, Bates N, Holmes B, Nagai T. Group differences and associations between patient-reported outcomes and physical characteristics in chronic low back pain patients and healthy controls. Clinical biomechanics (Bristol, Avon). 2023;106:106009. DOI 10.1016/j.clinbiomech.2023.106009 Source examined: Original abstract or metadata only; no original full-text numerical table validation.

Source note: SRC-0bba3d3fe41a Schilaty N 2023