Sit to stand assessment and prognosis after total hip arthroplasty

Executive assessment

Sit-to-stand (STS) after total hip arthroplasty (THA) is best assessed on two complementary levels: the ability to complete a specified transfer or repeated-transfer task, and the strategy used to accomplish it. A repetition count or completion time can improve while the patient continues to unload the operated limb. Conversely, a more symmetrical transfer is not necessarily faster, safer in every surgical context, or proven to reduce later falls or contralateral joint disease.

The 30-second chair stand and five-times sit-to-stand are practical clinical measures, but their protocols, populations and error estimates must remain distinct. Direct THA evidence includes a late-postoperative 30-second study with a reported SRD95 of 1.2 repetitions and an older unilateral-THA 5STS study reporting MDC95 2.91 s in its abstract, with the exact postoperative stage, chair, endpoint, retest interval and assistance protocol still unverified. A separate primary-THA candidate cohort reported preoperative 30-minute 30-second-test SDC 2.7 stands. These are not competing universal answers to the same question. The latter study also showed a retest improvement and failed prespecified construct-validity and responsiveness hypotheses. [1–5]

Original biomechanics studies make the distinction between task result and movement quality particularly clear. At 3 months, operated-limb force and joint moments remained lower despite improvement. At 1 year, a small selected cohort's total 5STS time no longer differed significantly from controls, yet lateral center-of-mass displacement remained abnormal. Neither study established a clinically important asymmetry boundary or a validated prognostic rule. [6–8]

Technology can extend assessment, but the claim must match the validation. A thigh-worn app counted repetitions with close clinician agreement in supervised mixed arthroplasty performances. This did not establish unsupervised home validity, between-day reliability or a THA-specific important-change threshold. Force feedback produced immediate changes in loading, with incomplete normalization of joint mechanics; a single-session response is not evidence of retained rehabilitation benefit or prevention of later harm. [7, 9]

The directly appraised literature is much stronger for measurement and recovery description than for using STS to forecast future participation, falls or long-term function after primary elective THA. Studies that include a chair test in a prediction battery, use STS as an outcome, or observe recovery over time should not be relabeled validated STS prognostic studies. For a rehabilitation tool, protocol-specific scoring with assistance, symptoms and movement observations is justified; a universal recovery or risk badge is not.

Scope and evidence approach

The main population is adults undergoing primary elective THA for hip OA. Preoperative testing is included as a baseline or potential predictor of postoperative outcome. Revision, hemiarthroplasty, fracture-related surgery, resurfacing and bilateral replacement are explicitly separated. The report examines single transfers, 5STS, 30-second chair stand, task-specific force and motion measures, portable technology, error and important change, and genuinely later functional outcomes. Strength and power constructs are discussed only where necessary to interpret the chair-rise assessment.

This is a critical narrative evidence synthesis with archived native database searches, source-access records and a study matrix. PubMed measurement, prognosis and biomechanics/technology streams were fully reconciled through official ESearch/EFetch because connector pagination overlapped. Scopus and bounded reference/citation searches supplemented them. The appendix distinguishes search retrieval from intensive full-text appraisal. This is not a registered systematic review, exhaustive dual-screening exercise or formal certainty grading.

What does a chair rise test measure

The task result

A single rise answers whether and how a transfer is possible under specified conditions. 5STS measures time to repeat a demanding transition a fixed number of times. The 30-second test fixes duration and counts achieved stands. The difference matters for floor effects: someone who can complete two rises may have a countable 30-second result but cannot provide an ordinary completed 5STS time. Record inability, hand use, assistance, pain and stopping separately rather than assigning an arbitrary maximum time.

These tests combine multiple capacities and strategies: lower-limb force, speed of force production, coordination, trunk momentum, balance, range of motion, pain tolerance and confidence. A test can correlate with strength without being a direct dynamometer measure. A higher count may result from a different movement strategy or reduced pain rather than an isolated increase in hip muscle capacity. The OARSI recommendation provides a common activity-based framework and makes the 30-second chair stand part of the minimum core set; it does not redefine it as a pure hip-strength assay. [1]

TUG contains a chair-rise phase but its total time also contains walking, turning and sitting. Gasparutto's 71-patient study partitioned the task at baseline and 6 months and showed that recovery differed across phases. Calling total TUG time an STS measure erases that distinction. Similarly, stand-to-sit and sit-to-walk are related transitions with distinct eccentric-control, momentum and balance demands. A paper abbreviating stand-to-sit as STS should not be silently read as sit-to-stand. [10, 11]

The movement strategy

Kinematic observations describe segment position and motion, while forces and inverse-dynamics moments describe different aspects of loading. Lateral trunk displacement, a center-of-mass shift, unequal foot force and unequal hip moment are related but not interchangeable. A person may distribute vertical force relatively evenly while generating different joint moments because of foot position, trunk inclination and lever arms.

Keep both limb values visible. A ratio near one can conceal bilateral weakness or reduced total task demand. A difference score near zero can arise from improvement of the operated limb, deterioration of the other limb, or altered movement speed. Do not call the nonoperated side unaffected without evidence; contralateral OA, previous THA, knee disease and pain all change interpretation.

The clinical task should remain meaningful to the person's daily life. Rapid repeated rises are useful capacity challenges, but most ordinary transfers occur singly. Esbjörnsson's study found that some asymmetries were most apparent in the first cycles and diminished during later repetitions. Averaging a whole repeated task can therefore hide a clinically relevant initial strategy. [8]

Table 1 Choose the transfer task deliberately

Protocol and postoperative context

Chair feet arms and endpoints

Record actual seat height, firmness, backrest and armrests, shoes, foot placement, initial trunk position and whether hands are permitted. A fixed-height chair supports reproducibility across visits but imposes different relative demands on people of different leg length. An individually adjusted knee-height stool controls one biomechanical relationship but is not the same test as a fixed 43-cm chair. Cushions can change both height and compliance.

Define the timing endpoints. Starting on a verbal cue includes reaction time; starting at first motion does not. Finishing at the fifth full stand differs from returning to the seat after the fifth rise. A count rule that credits a final more-than-half-complete stand differs from counting only complete stand-sit cycles. The exact rule should appear in the record, not merely the label 5STS or 30CST.

Familiarization, practice repetitions, rests, encouragement and trial aggregation matter. Best-of-two emphasizes peak performance and may magnify favorable random variation. A mean of two answers a different question. Video rescoring of the same performance estimates rater/event-detection agreement; asking the person to repeat the task estimates additional performance variability. A later-day repeat is a third design.

Early restrictions and assistance

In acute care, medical and surgical clearance comes first. Follow the treating team's actual weight-bearing and movement instructions. Do not mandate a low chair or unsupported rise to preserve a research protocol when that would be inappropriate. A modified or assisted version may still be clinically useful, but should be labeled as such and not assigned a threshold established for an unassisted standard task.

Document orthostatic symptoms, analgesia, fatigue and pain. A day-2 failed rise can reflect transient postoperative factors; a slow test years later may reflect chronic bilateral disease or general deconditioning. Record exact days after surgery rather than relying only on labels such as acute or chronic.

Surgical approach may influence early muscle function and compensatory options, but these assessment studies do not justify a universal approach-specific trajectory. Abujaber's longitudinal sample included several approaches; Esbjörnsson's cohort used anterolateral surgery with immediate full weight bearing and no movement restrictions. Such differences are modifiers of interpretation rather than evidence that one measurement threshold transfers across approaches. [6, 8]

Reliability error and important change

Late THA 30 second chair stand

Unver and colleagues studied 37 primary THA recipients at least 1 year after surgery, on average 5.3 years. Mean age was 54.5 years and no one needed a walking aid during testing. The protocol used a 17-inch chair, arms crossed, standardized seat positioning and a practice stand. Two test occasions were separated by 1 hour of seated rest. The appendix credited a final more-than-half-complete stand. [3]

The original Table II reports ICC(2,1) 0.94 (95% CI 0.88–0.97), SEM 0.4 repetitions and SRD95 1.2 repetitions. Mean count increased from 12.8 to 13.4. The authors derived SEM from the repeated-measures error term, rather than stating the simple cross-sectional-SD formula often used in secondary summaries. Preserve their reported values and method; neither the displayed ICC nor an independently substituted formula licenses silently rewriting their SEM.

These results support same-day reproducibility in a selected late-postoperative sample. They do not establish error during the first postoperative weeks, between-day stability, a patient-important improvement, or a safe home-testing rule. For integer counts, a reported fractional error is a statistical boundary, not a fractional achievable repetition. A display can retain the original estimate while avoiding an automatic assertion that any particular count change is important.

Preoperative candidates followed through THA

Tolk's 90-person cohort included unilateral symptomatic hip-OA patients scheduled for primary THA; the reliability subset had 30 participants and only a 30-minute rest between tests. The chair height was 43 cm. The original supplement gives ICC 0.86 (95% CI 0.66–0.94), SEM 0.99 and SDC 2.7 stands. The SDC magnitude is consistent with the conventional individual 95% formula, but the original table labels it SDC without a separate confidence designation. Retest count improved by 0.8 stands, with a confidence interval excluding zero. [2]

Thus, the evidence supports reasonably stable ranking while also showing a learning or repeat-performance shift. A high point ICC does not eliminate that bias. More importantly, these are preoperative estimates, even though the same cohort was followed to 12 months after surgery. They cannot be described as postoperative reliability solely because THA appears in the cohort description.

The late-THA SRD95 of 1.2 and preoperative SDC of 2.7 should not be averaged, selected by convenience or used to create a single hip-replacement threshold. Stage, sample function, protocol, retest interval and statistical method differ. Dobson's 2017 mixed hip/knee OA study is useful contextual evidence for OARSI testing but excluded previous replacement; it is not a postoperative validation study. [2, 3, 5]

Five times sit to stand

Özden and colleagues provide direct unilateral-THA evidence in 32 older adults, mean age 75.4 years. The original abstract reports 5STS ICC 0.987, SEM 1.05 s and MDC95 2.91 s, with correlations of −0.522 with Harris Hip Score and 0.730 with TUG. These support relative reproducibility and convergent association in the studied cohort. [4]

The full article could not be obtained through the permitted sources. Consequently, the exact chair, timing endpoint, postoperative interval, retest interval, trial aggregation and assistance policy remain unverified. The high ICC does not remove those implementation gaps. Do not attach 2.91 s to a new protocol merely because it is called 5STS, or present correlation with a composite hip score as criterion validity for muscle power, loading symmetry or future independence.

Table 2 Chair rise error estimates are stage and protocol specific

Is a change important

MDC/SDC/SRD estimates concern measurement error; MIC/MCID concerns importance. Responsiveness is the ability to detect change in the intended construct. None follows automatically from a statistically significant pre/post difference or a large effect size. There is no validated universal THA chair-rise MIC established by the directly appraised originals in this report.

Tolk's construct and change results are important counterweights to simple reliability claims. Only 4 of 9 construct hypotheses and 4 of 8 responsiveness hypotheses were confirmed for 30CST. Its change score correlated only 0.37 with the 12-month global-change anchor. The supplement shows strong concentration in much/very-much-improved categories, with very few minimally improved or unchanged participants. That is a weak basis for inferring a minimal-important boundary. [2]

Interpret the findings critically without treating PROMs as a perfect gold standard. Perceived difficulty, pain and observed repeated-rise capacity are different constructs, so some weak correlations are expected. However, the prespecified validation failures still constrain broad claims that the test measures all relevant daily function. The supplement also contains reporting inconsistencies in anchor wording and OHS scoring description. These warrant explicit caution, not an invented corrected threshold.

At the individual level, explain what changed, whether the protocol and symptoms were comparable, whether it exceeded a reasonably applicable error estimate, and whether the patient reports improvement in a valued transfer or activity. A person can have worthwhile improvement smaller than an uncertain MDC; another can exceed MDC without achieving a meaningful goal. Neither situation is resolved by transferring knee-OA, TKA or stroke thresholds.

Instrumented assessment and movement quality

Operated limb unloading at three months

Abujaber's prospective longitudinal study included 45 THA patients and 23 controls. Patients were tested 2–4 weeks before and 3 months after surgery. An adjustable armless/backless stool was set to knee-joint height; feet were unconstrained, arms rested in the lap, pace was self-selected and three trials followed two practice attempts. This is a controlled single-rise biomechanical task, not a standard fast 5STS or 30-second count. [6]

Peak vertical force on the operated side increased, and nonoperated force decreased, after surgery, but interlimb differences remained. The published normalized force values were 0.54 versus 0.64 at 3 months, compared with approximately 0.61 and 0.60 in controls. External moments also remained asymmetric. Preserve the paper's body-weight and mass/height normalization; a normalized vertical force is not an absolute Newton value or a direct intra-articular contact force.

This demonstrates that symptom relief and improved task performance do not guarantee restoration of symmetrical mechanics. It does not prove that every asymmetry is harmful, identify a minimal-important asymmetry threshold, or establish that changing the asymmetry prevents contralateral OA. Selection, exclusion of important contralateral involvement and differences in body size between patients and controls constrain generalization. Three-month findings should not be advertised as permanent deficits.

Similar total time with persistent compensation at one year

Esbjörnsson and Naili followed a cohort with primary unilateral hip OA through THA and analyzed 28 patients and 21 controls. The initial patient cohort was 40: three were excluded after contralateral THA, two could not perform the test without using their arms, and seven had marker occlusion. These exclusions matter for a technology intended to work in ordinary rehabilitation. [8]

The 5STS used a 44.5-cm bench without arm/back support, arms across the chest, maximum speed, a practice repetition and the faster of two trials. Time decreased from 15.1 to 11.5 s, compared with 10.1 s in controls; the postoperative time difference was not statistically significant. Nevertheless, lateral center-of-mass displacement remained greater after THA, particularly in the initial cycles. The analysis excluded the fifth cycle from trajectory analysis because it contained only the rising transition, leaving four complete cycles.

The center-of-mass measure was derived from a full-body marker model, not from one trunk point or a force-plate center of pressure. Its area under the trajectory is also not ROC discrimination, despite the shared abbreviation AUC. The study supports a longitudinally responsive research descriptor and persistence of a group-level compensation. It did not report test-retest MDC or a patient-anchored MIC for that descriptor, nor validate visual observation as numerically interchangeable with it.

Why biomechanical studies appear to disagree

Caplan's small study followed seven THA and seven resurfacing patients. Its original abstract reports that the THA subgroup regained approximately symmetrical peak-force and impulse ratios by 12 months, whereas the resurfacing subgroup showed a different pattern. Miura's reports and Talis's work describe persistent offloading at other times and under other protocols. These findings should not be collapsed into a single statement that symmetry always does or never does recover. [12–16]

Several distinctions can explain disagreement: a single rise versus repeated rises; peak force versus impulse; free versus constrained feet; adjusted versus fixed chair height; definition and direction of the ratio; surgical approach; contralateral disease; and postoperative time. A nonsignificant group comparison with seven THA patients is not a formal equivalence demonstration. Likewise, an average group difference does not provide an individual abnormality threshold.

Wang's 2021 review is useful for mapping this diversity, but included revision, resurfacing and bilateral evidence alongside primary THA. The 2025 asymmetry review more narrowly selected primary unilateral THA and identified seven studies, generally showing operated-limb unloading. The 2026 beyond-walking review again included resurfacing and emphasized poorly reported approach and heterogeneous tasks. Their conclusions provide context; original denominator, units and protocol remain necessary before adopting a numerical claim. [17–19]

Define symmetry before computing it

A ratio operated/nonoperated has symmetry at one. Operated force divided by total bilateral force has symmetry at one half. Operated-minus-nonoperated difference has symmetry at zero. An absolute percentage index removes direction. These cannot share a common numeric cutoff. Abujaber's feedback study used an unscaled operated-minus-nonoperated difference for each variable, with negative values representing lower operated-side output. [7]

A peak on each limb may occur at different instants. Comparing two independent peaks differs from comparing force at seat-off or at the instant of maximum bilateral force. Impulse requires an explicit integration phase. Report the formula, sign, phase, time normalization and denominator. Keep absolute limb outputs, total duration and task success alongside symmetry, and avoid divisions by a near-zero moment when a ratio becomes unstable.

Force plates directly measure external forces at the feet. Hip/knee moments additionally depend on motion data, anthropometry and modeling. Two bathroom scales may provide useful static feedback but cannot be presumed to reproduce dynamic impulse, rapid peaks or inverse-dynamics joint moments. A camera-derived lateral lean is similarly not a force measurement.

Table 3 Movement measures are not interchangeable

Portable sensing feedback and power claims

What app agreement establishes

Lippi's Step-App cohort consisted of 25 participants, including 20 hip and five knee arthroplasties; four surgical indications were hip fracture. Baseline was approximately 12 days after surgery, followed by four weeks of rehabilitation. Chair-rise counts were assessed simultaneously by the app and an experienced clinician. For the chair test, the device was on the anterior thigh; a 43.2-cm chair could be raised with cushions to accommodate precautions. [9]

Perfect observed agreement in this small set is promising for supervised repetition detection. It does not establish performance in unseen phones, loose sensor placement, partial rises, hand-assisted tasks, unsupervised homes or people unable to follow instructions. It also does not establish that the modified chair test is interchangeable with a fixed-height OARSI version. Same-trial scoring agreement and recovery over four weeks should not be called between-day test-retest reliability.

For video or wearable deployment, validate the exact event and output. Required outcomes may include start/end timing, stand completion, hand use, foot movement, trunk angle, repetition count and algorithm failure. Each has a different reference standard and error tolerance. Retain invalid or unscorable trials and the reason, rather than treating technical failure as clinical incapacity or silently dropping difficult patients.

Feedback is an intervention and changes the test

Abujaber's visual-feedback study used bilateral force plates and displayed weight distribution during STS. It analyzed 35 preoperative and 27 three-month postoperative participants who met an asymmetry selection criterion; the pre/post samples were not a fully repeated identical cohort. The no-feedback condition always preceded feedback. Immediate force symmetry improved, but not every joint-moment or kinematic asymmetry normalized. [7]

The selection boundary of ±0.06 normalized force difference was based on a control-group interval. It was an experimental inclusion rule, not an established THA MIC or harm threshold. The fixed order permits practice and cueing effects, and the study did not test long-term retention, later function, falls or contralateral disease. Its relationship to the earlier Delaware biomechanical work also means it should not be treated as wholly independent replication.

If an app supplies real-time feedback, label that test as feedback-assisted. Comparing an uncoached baseline with a coached follow-up mixes changes in capacity with changes in instruction. A separate uncoached assessment can help distinguish retained movement behavior from temporary task compliance.

Count time estimated power and measured power

A chair count is not mechanical power, and a completion time alone does not measure rate of force development. Power requires work or force and velocity over a defined phase. A simple STS-power equation usually adds body mass, assumed displacement and timing assumptions; its output is model-estimated power, not directly measured hip power. Chair height and leg length therefore become inputs to the estimate rather than incidental background.

Instrumented whole-body power and hip joint power answer different questions. Joint power combines a modeled joint moment and angular velocity, with sign conventions for generation and absorption. Net external mechanical power during rising does not identify which limb or joint supplied it. RFD additionally depends on force onset, sampling, filtering, force-window definition and movement phase. The gait/strength or healthy-older-adult validation of an equation cannot establish its individual error or prognostic validity in postoperative THA.

The directly appraised THA STS studies do not establish a universal equation-derived power or RFD threshold for recovery, falls or treatment response. A tool can present such estimates if the model is transparent and appropriately validated, but should not quietly replace a repetition count with a clinically calibrated power score.

Prognosis and recovery interpretation

Longitudinal change is not predictive validation

A preoperative-to-postoperative study demonstrates what changed in the observed cohort. It becomes prognostic evidence only when a measurement at an earlier index time is related to a distinct later outcome under a suitable analysis. Describing improvement, correlating variables at one visit, or demonstrating immediate response to feedback is not sufficient.

The Tolk, Abujaber and Esbjörnsson studies inform measurement and recovery. They do not establish that a particular chair-rise count or asymmetry predicts future falls, discharge safety or participation. Large patient-average changes after surgery also do not establish an individual's likely recovery trajectory. A predictor of later status is not necessarily a predictor of improvement after accounting for baseline, and neither demonstrates a causal benefit of training that predictor. [2, 6–8]

What the prediction literature does and does not provide

Kawano's 321-person retrospective study considered preoperative and three-week physical tests, including STS, when developing a 1-year UCLA activity rule. The published final five-factor rule included age, preoperative activity, hip abductor strength, knee extensor strength and postoperative 10MWT; STS was not among the reported retained factors. Merely being measured as a candidate does not validate STS as an independent prognostic test. The endpoint was self-reported activity, and the original abstract does not establish external validation. [20]

Christensen's 2026 report linked cumulative gait-loading biomarkers with 26-week outcomes including 30-second STS. In that analysis STS was an outcome; it was not the predictor being validated. The available abstract also leaves the predictor timing insufficiently clear for strong prospective claims. It is an important new source for further appraisal, but does not supply a future-function rule based on today's chair test. [21]

The targeted search also retrieved seemingly relevant preoperative chair-rise papers in TKA and concurrent discrimination studies of postoperative independent ambulation. These are not evidence of THA-specific STS prognosis. The absence of a well-validated rule in this appraisal should be stated as a source- and scope-limited conclusion, rather than a claim that no such research could exist.

Table 4 Recovery evidence and prognostic limits

Falls contralateral disease and participation

Mechanically plausible concern about nonoperated-limb loading is not direct evidence that a specific STS asymmetry causes future OA or a fall. These outcomes need prospective ascertainment and adjustment for baseline disease, exposure, age, strength, pain and comorbidity. A therapeutic recommendation to work on safe, efficient transfers may be reasonable without presenting the mechanism as proven prevention.

Participation must also be measured rather than inferred. Jeldi's longitudinal cohort found no increase in daily activity-volume measures, including sit-to-stand transitions, despite improved pain and functional capacity. The number of transitions performed in everyday life depends on routine and opportunity, and is distinct from maximum 30-second capacity. More transitions are not invariably better; their meaning depends on the person's goals and environment. [22]

For future validation, distinguish independent transfer, safe low-seat access, clinic repetition performance, real-world transfers, work participation, falls and contralateral symptoms. A model for one endpoint should not be promoted as predicting all of them. Clinical utility requires calibration and an actionable decision, not only a significant regression coefficient.

A practical assessment pathway

First establish safety, current restrictions and the question. If the immediate question is independence, document a single transfer, assistance, arm use and actual chair. If the question is repeated-transfer capacity, choose a standardized 5STS or 30-second protocol that the person can safely perform and keep it constant. Noncompletion remains part of the outcome.

Record time/count together with symptoms and key movement observations. Note lateral shift, marked trunk momentum, foot repositioning and visible reliance on one side, but do not give these observations a numerical force interpretation without validation. Where detailed loading matters, use a suitably validated force-based system and preserve both limb outputs alongside a clearly defined symmetry index.

At follow-up, verify that seat, arms, feet, footwear, instruction, assistance, trials and postoperative context are comparable. Report absolute change and the applicability of any source-specific error estimate. Ask whether a valued transfer has become easier or possible, and keep this patient-important judgment separate from MDC.

A rehabilitation application should store raw score, protocol version, actual chair height, aid/assistance, surgery details, exact postoperative day, pain/fatigue, trial aggregation and quality flags. It should distinguish independent, modified, assisted, incomplete, unsafe and technically unscorable tests. Do not issue a universal recovered/not-recovered classification from repetition count alone.

Table 5 Minimum record for a rehabilitation tool

Research priorities and conclusion

The main needs are stage-specific between-day reliability, rigorous important-change anchors, criterion agreement of portable motion/force estimates, and prospective validation against outcomes that matter to patients. Studies should retain patients with inability and aids, report bilateral disease and approach/restrictions, separate limb and participant statistical units, and investigate how task modifications change interpretation. Multicenter validation should separate people, both limbs and all visits across model-development and test sets.

STS already provides a useful, feasible record of transfer capacity after THA. Its clinical value improves when movement strategy is considered alongside task success, and when stage and protocol are explicit. The central evidence-based limit is equally important: neither a fast chair test nor a symmetrical-looking rise has been shown here to certify complete recovery or accurately forecast every later functional risk.

Primary study characteristics

Original studies and explicitly labeled contextual sources are grouped by question. Population, postoperative stage, protocol, endpoint, source access and analysis design constrain interpretation. Publications from the same cohort are not independent replications.

Framework and contextual evidence

Dobson F 2013

Study and population [1] Consensus framework. International consensus for hip/knee OA and joint replacement

Protocol and timing Activity-based test selection using evidence, feasibility and expert consensus

Principal findings 30-second chair stand, 40-m fast-paced walk and stair climb form the minimum set; TUG and 6MWT are additional

Interpretive limits Consensus does not supply universal postoperative error, importance or prediction thresholds

Source examined Original article body retrieved

Dobson F 2017

Study and population [5] Direct measurement evidence; nonoperative boundary. 51 stable hip and/or knee OA participants; prior replacement excluded

Protocol and timing Independent raters within a session and same-rater repeat about a week later; standardized OARSI tests

Principal findings Useful nonoperative evidence for standardization and reproducibility

Interpretive limits Mixed joints and nonoperative stage; numerical original tables incompletely extracted; cannot be relabeled postoperative THA

Source examined Original article body retrieved; numerical original tables incomplete in extraction; nonoperative mixed OA context

Wang J 2021

Study and population [17] Systematic review used for context/discovery. 11 heterogeneous studies including primary, revision, resurfacing and bilateral evidence

Protocol and timing Review of STS kinematic/kinetic measures and differing symmetry definitions

Principal findings Compensation common, with findings varying by time and task

Interpretive limits Useful discovery/context source; numerical approximations require originals; no proof of falls or contralateral-disease prevention

Source examined Original article body retrieved

Almonroeder TG 2025

Study and population [18] Scoping review, abstract-level. Seven primary unilateral THA studies, with postoperative times from 10 weeks to 19 months

Protocol and timing Review requiring bilateral ground-reaction-force measurement during STS

Principal findings Operated-limb unloading common; three of four controlled studies found greater asymmetry

Interpretive limits Original abstract only; does not establish MDC, MIC or a risk threshold

Source examined Original abstract only; full article not retrieved

Mbarki H 2026

Study and population [19] Scoping review, abstract-level. 83 studies, 2,047 THA and 170 resurfacing patients

Protocol and timing Functional tasks beyond walking; balance, STS and stairs common

Principal findings Heterogeneous tasks, populations and approach reporting

Interpretive limits Original abstract only; broader than primary THA and STS; not individual measurement or prediction validation

Source examined Original abstract only; full article not retrieved

Clinical measurement properties and important change

Tolk JJ 2019

Study and population [2] Direct measurement evidence; hypothesis-based validity/responsiveness. 90 unilateral symptomatic hip-OA candidates for primary THA; reliability subset n = 30; follow-up at 12 months

Protocol and timing Preoperative retest after 30 minutes; 43-cm chair; standardized OARSI tasks, with walking aids recorded

Principal findings 30CST ICC 0.86, SEM 0.99, SDC 2.7 stands; walk ICC 0.94, SEM 0.08 m/s, SDC 0.22 m/s; validity/change hypotheses not confirmed

Interpretive limits SDC confidence level not separately labeled; chair retest improved 0.8 stands; anchor responses concentrated in major improvement; supplementary wording/scoring discrepancies

Source examined Original article body and original supplementary PDF retrieved; supplementary Tables 2–4 visually checked

Unver B 2015

Study and population [3] Direct measurement evidence. 37 primary THA recipients, mean age 54.5 years; at least 1 year and mean 5.3 years postoperative; no aids

Protocol and timing 17-inch chair, arms crossed, practice stand; two occasions 1 hour apart; walking methods and appendix disagree about turning

Principal findings 30CST ICC 0.94, SEM 0.4 repetitions, SRD95 1.2 repetitions; 50FWT ICC 0.98, SEM 0.3 s, SRD95 0.8 s

Interpretive limits Selected stable late-stage sample; same-day evidence; no MIC; SEM derived from error mean square; walking course ambiguity unresolved

Source examined Original publisher PDF retrieved; Table II and appendix visually checked

Özden F 2020

Study and population [4] Direct measurement evidence, abstract-level. 32 unilateral primary THA recipients, mean age 75.4 ± 10.3 years

Protocol and timing Two FTST/step repetitions; chair, stage, endpoints and retest interval unverified

Principal findings 5STS ICC 0.987, SEM 1.05 s, MDC95 2.91 s; HHS correlation −0.522 and TUG correlation 0.730

Interpretive limits No MIC or prospective prognosis established; right/left step data are not automatically operative/nonoperative data

Source examined Original abstract only; full article not retrieved

Instrumented assessment and recovery

Abujaber SB 2015

Study and population [6] Longitudinal biomechanical recovery. 45 THA recipients and 23 controls; baseline 2–4 weeks before and 3 months after surgery; mixed approaches

Protocol and timing Knee-height adjustable stool; self-selected pace; arms in lap; three trials after two practices; motion capture and dual force plates

Principal findings Operated normalized VGRF 0.51 to 0.54; nonoperated 0.67 to 0.64; residual moment asymmetry

Interpretive limits Not a standard 30CST/5STS; preserve force/moment normalization; contralateral selection; no MIC or later-harm endpoint

Source examined Original article body retrieved

Abujaber S 2017

Study and population [7] Immediate experimental response; companion cohort. 35 preoperative and 27 postoperative asymmetric participants; not a fully paired longitudinal sample

Protocol and timing Three uncoached then three force-feedback trials; adjustable stool; symmetry defined as operated minus nonoperated

Principal findings Immediate force symmetry improved without uniform normalization of joint mechanics

Interpretive limits Fixed order; 0.06 normalized-force inclusion rule is not MIC; no retained benefit or falls-prevention assessment; related Delaware cohort

Source examined Original article body retrieved

Esbjörnsson AC 2020

Study and population [8] Longitudinal biomechanics/recovery. 28 of 40 patients and 21 of 25 controls; anterolateral THA; 12.2 ± 1.1-month follow-up

Protocol and timing 44.5-cm bench; fast 5STS; arms crossed; best of two; full-body CoM trajectories from four complete cycles

Principal findings Time 15.1 to 11.5 s versus controls 10.1 s; persistent lateral CoM compensation despite pain improvement

Interpretive limits Two arm-dependent and seven marker-occluded patients excluded; CoM is not COP; no trajectory MDC/MIC; nonsignificant time difference is not equivalence

Source examined Original open-access full XML, including body and tables, retrieved

Miura N 2018

Study and population [12] Cross-sectional biomechanics, abstract-level. The original abstract describes 28 THA patients and 16 controls assessed at one year. The women-only description is reported in Wang’s review and remains to be checked in the original methods; detailed eligibility unavailable

Protocol and timing STS loading compared with controls; full protocol not retrieved

Principal findings Persistent asymmetrical loading reported

Interpretive limits Original abstract only; no protocol-specific error or importance threshold can be reconstructed from the review

Source examined Original abstract only; full article not retrieved

Miura N 2018

Study and population [13] Longitudinal loading recovery, abstract-level. THA recipients followed through 1 year; original full methods unavailable

Protocol and timing Leg loading during quiet standing and chair-rise movement

Principal findings Temporal recovery of operated-limb loading described

Interpretive limits No individual MDC/MIC or prospectively validated harm threshold established from available material

Source examined Original abstract only; full article not retrieved

Caplan N 2014

Study and population [14] Small longitudinal biomechanical comparison, abstract-level. Seven THA and seven resurfacing patients with matched controls; baseline, 3 months and 12 months

Protocol and timing Per-limb peak VGRF and impulse symmetry ratios during rising

Principal findings THA ratios approached one at 12 months; resurfacing followed a different pattern

Interpretive limits Very small THA subgroup; nonsignificance is not equivalence; resurfacing is not THA replication; no MDC/MIC

Source examined Original abstract only; full article not retrieved

Lamontagne M 2012

Study and population [15] Cross-sectional biomechanics, abstract-level. THA recipients compared with healthy participants; original full methods unavailable

Protocol and timing Lower-limb joint mechanics during sitting and standing

Principal findings Residual hip-mechanical differences reported

Interpretive limits Review approximations for moments and power not reproduced as original-source-verified values

Source examined Original abstract only; full article not retrieved

Talis VL 2008

Study and population [16] Cross-sectional loading comparison, abstract-level. Unilateral THA recipients and controls; postoperative-stage distribution is described by a secondary review and requires original-source confirmation

Protocol and timing Force/loading during quiet standing, walking and chair rising

Principal findings Task-dependent loading asymmetry reported

Interpretive limits Different task constructs; no individual longitudinal error or prospective harm threshold; original body unavailable

Source examined Original abstract only; full article not retrieved

Gasparutto X 2021

Study and population [10] Instrumented recovery context. 71 primary hip-OA THA patients and 52 controls; preoperative and 6-month testing; important bilateral/other disease excluded

Protocol and timing 47-cm armchair; support allowed; self-selected TUG; fastest of first three trials; optical phase partition

Principal findings Different component tasks showed different deficits and recovery, with substantial individual variability

Interpretive limits Composite TUG is not pure STS; no phase-specific MIC, MDC or prospective prediction validation

Source examined Original article body retrieved

Lippi L 2024

Study and population [9] Concurrent agreement/rehabilitation context. 25 of 42 assessed participants; 20 hip and five knee recipients; four fracture indications; baseline about 12 days postoperative

Protocol and timing Simultaneous clinician/app scoring; thigh sensor for 30CST; 43.2-cm chair raised with cushions when needed; four-week rehabilitation interval

Principal findings High same-trial supervised walking correlations; perfect observed chair-rise count agreement in Figure 8. Walking Figures 5–7 show systematic offsets and nonzero limits of agreement; plotted units and clinical tolerances require clarification before claiming interchangeability

Interpretive limits Mixed procedures and indications; no unsupervised home or between-day validation; modified chair height; agreement figures now inspected; walking-unit interpretation and clinical tolerances remain unresolved

Source examined Original article body retrieved; agreement figures now visually inspected; walking-unit interpretation remains unresolved; mixed procedures/indications

Jeldi AJ 2017

Study and population [22] Longitudinal capacity/performance context, abstract-level. 30 THA recipients, mean age 67 years; preoperative, 3-month and 12-month observations

Protocol and timing Objectively measured daily activity with 6MWT, Harris Hip Score and Oxford Hip Score

Principal findings Pain and function improved without corresponding increases in activity-volume measures

Interpretive limits Capacity and everyday behavior differ; original full article unavailable; no chair-rise prognostic rule

Source examined Original abstract only; full article not retrieved

Temporiti F 2019

Study and population [11] Early postoperative comparison, abstract-level. 20 unilateral and 20 one-stage bilateral THA patients; before surgery and days 3 and 7

Protocol and timing TUG, quiet-standing COP and body-weight distribution during the transition labeled stand-to-sit

Principal findings Different distribution and stability patterns between unilateral and bilateral procedures

Interpretive limits Abstract explicitly labels STS as stand-to-sit; do not assume sit-to-stand; bilateral comparison is not unilateral reliability validation

Source examined Original abstract only; full article not retrieved

Prognostic questions and temporal ordering

Kawano T 2022

Study and population [20] Development clinical prediction rule, abstract-level. 321 primary THA recipients, including 56 men; retrospective development cohort

Protocol and timing Preoperative and 3-week tests; 1-year UCLA activity category

Principal findings Final rule used age, prior activity, hip/knee strength and postoperative 10MWT; STS was not retained

Interpretive limits Self-reported activity; cutoffs and high in-sample probabilities not externally validated here; full methods unavailable

Source examined Original abstract only; full article not retrieved

Christensen JC 2026

Study and population [21] Association with later-recovery outcomes; temporal status unverified. 56 primary unilateral THA recipients; functional outcomes assessed at 26 weeks

Protocol and timing Cumulative loading measures multiplied by daily steps and related to 6MWT, 30STS, WOMAC and strength

Principal findings Cumulative loading rate associated with several functional outcomes

Interpretive limits Abstract insufficient to verify predictor timing; STS is an outcome, not a validated predictor; full article unavailable

Source examined Original abstract only; full article not retrieved

Search and source access appendix

Search coverage

Across the three overlapping streams, there were 139 unique official PubMed records and 158 unique Scopus records. These are database-specific retrieval counts, not unique cross-database publications or eligible studies. They must not be added as independent evidence.

The exact dated PubMed queries were reconciled against official ESearch identifiers and complete EFetch records, including nonstandard record types. Scopus retrieval reached terminal coverage, with unique identifiers matching each reported total.

The searches were intentionally broad. Surgical mechanics, treatment comparisons, revision/fracture procedures, unrelated acronyms and off-domain papers were retained during retrieval and separated during targeted appraisal. Selection for intensive appraisal favored direct measurement properties, important-change anchors, true temporal outcomes, contradictory findings and implementation-relevant technology. Search retrieval is more extensive than full-text appraisal.

PubMed used an explicit publication-date range through 2026/10/02. Scopus used PUBYEAR BEF 2027; year-based constraints and indexing lags can miss articles first available online in 2026 but assigned to a later issue. Targeted source searching and citation discovery reduce, but do not eliminate, such gaps. No claim of complete coverage of all publications is made.

Supplemental discovery

Bounded reference and forward-citation searches used the Tolk hip-OA measurement study, the 2021 Wang sit-to-stand review, the 2021 Labanca balance review, the 2021 abductor-strength review, the 2020 Shibuya prognosis study and the 2016 THA prognosis review. Each request was capped at 100 records per provider (OpenAlex/Semantic Scholar). Capped citation networks are not exhaustive. Targeted official-source web searches identified or checked recent important-change, wearable, falls, chair-rise and biomechanical reports.

Exact native queries

Sit to stand measurement PubMed

("Arthroplasty, Replacement, Hip"[MeSH Terms] OR "total hip arthroplast*"[Title/Abstract] OR "total hip replacement*"[Title/Abstract]) AND ("sit to stand"[Title/Abstract] OR "sit-to-stand"[Title/Abstract] OR "stand to sit"[Title/Abstract] OR "stand-to-sit"[Title/Abstract] OR "chair rise"[Title/Abstract] OR "chair-rise"[Title/Abstract] OR "chair stand"[Title/Abstract] OR "chair-stand"[Title/Abstract] OR "sit to walk"[Title/Abstract] OR "sit-to-walk"[Title/Abstract] OR 5STS[Title/Abstract] OR FTSTS[Title/Abstract] OR 5TSTS[Title/Abstract] OR 30sCST[Title/Abstract] OR "repeated chair"[Title/Abstract] OR "chair rising"[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])

Sit to stand measurement Scopus

TITLE-ABS-KEY(("total hip arthroplast*" OR "total hip replacement*" OR THA OR THR) AND ("sit to stand" OR "sit-to-stand" OR "stand to sit" OR "stand-to-sit" OR "chair rise" OR "chair-rise" OR "chair stand" OR "chair-stand" OR "sit to walk" OR "sit-to-walk" OR 5STS OR FTSTS OR 5TSTS OR 30sCST OR "repeated chair" OR "chair rising") 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

Sit to stand prognosis PubMed

("Arthroplasty, Replacement, Hip"[MeSH Terms] OR "total hip arthroplast*"[Title/Abstract] OR "total hip replacement*"[Title/Abstract]) AND ("sit to stand"[Title/Abstract] OR "sit-to-stand"[Title/Abstract] OR "stand to sit"[Title/Abstract] OR "stand-to-sit"[Title/Abstract] OR "chair rise"[Title/Abstract] OR "chair-rise"[Title/Abstract] OR "chair stand"[Title/Abstract] OR "chair-stand"[Title/Abstract] OR "sit to walk"[Title/Abstract] OR "sit-to-walk"[Title/Abstract] OR 5STS[Title/Abstract] OR FTSTS[Title/Abstract] OR 5TSTS[Title/Abstract] OR 30sCST[Title/Abstract] OR "repeated chair"[Title/Abstract] OR "chair rising"[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])

Sit to stand prognosis Scopus

TITLE-ABS-KEY(("total hip arthroplast*" OR "total hip replacement*" OR THA OR THR) AND ("sit to stand" OR "sit-to-stand" OR "stand to sit" OR "stand-to-sit" OR "chair rise" OR "chair-rise" OR "chair stand" OR "chair-stand" OR "sit to walk" OR "sit-to-walk" OR 5STS OR FTSTS OR 5TSTS OR 30sCST OR "repeated chair" OR "chair rising") 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

Sit to stand protocol mechanism technology PubMed

("Arthroplasty, Replacement, Hip"[MeSH Terms] OR "total hip arthroplast*"[Title/Abstract] OR "total hip replacement*"[Title/Abstract]) AND ("sit to stand"[Title/Abstract] OR "sit-to-stand"[Title/Abstract] OR "stand to sit"[Title/Abstract] OR "stand-to-sit"[Title/Abstract] OR "chair rise"[Title/Abstract] OR "chair-rise"[Title/Abstract] OR "chair stand"[Title/Abstract] OR "chair-stand"[Title/Abstract] OR "sit to walk"[Title/Abstract] OR "sit-to-walk"[Title/Abstract] OR 5STS[Title/Abstract] OR FTSTS[Title/Abstract] OR 5TSTS[Title/Abstract] OR 30sCST[Title/Abstract] OR "repeated chair"[Title/Abstract] OR "chair rising"[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])

Sit to stand protocol mechanism technology Scopus

TITLE-ABS-KEY(("total hip arthroplast*" OR "total hip replacement*" OR THA OR THR) AND ("sit to stand" OR "sit-to-stand" OR "stand to sit" OR "stand-to-sit" OR "chair rise" OR "chair-rise" OR "chair stand" OR "chair-stand" OR "sit to walk" OR "sit-to-walk" OR 5STS OR FTSTS OR 5TSTS OR 30sCST OR "repeated chair" OR "chair rising") 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

Source access and appraisal

Exclusions and related evidence

Primary elective OA THA is the principal inference population. Fracture/hemiarthroplasty, revision, resurfacing, bilateral THA and mixed hip/knee samples are excluded from unqualified primary-THA conclusions or explicitly labeled contextual evidence. The 2025 multidisciplinary preoperative 30STS/TUG article, DOI 10.3390/jcm14041085, was retrieved and excluded from THA inference because its sample was TKA-only. Stand-to-sit is not silently relabeled sit-to-stand. Companion Delaware biomechanics/feedback reports are not counted as independent replication. Nonoperative hip/knee OA reliability is kept separate from postoperative evidence.

The primary study appendix records evidence class, population, protocol, principal findings, limitations and source access. Unavailable full text is not an exclusion based on an assumed result. This appendix is an audit of the work performed, not a PRISMA flow diagram or a registered systematic-review protocol.

References

References are numbered in first citation order. Source descriptions identify the material examined and do not constitute a study quality rating. Each link identifies the original publication or explicitly named primary source version.

1. Dobson F, Hinman RS, Roos EM, Abbott JH, Stratford P, Davis AM, et al. OARSI recommended performance-based tests to assess physical function in people diagnosed with hip or knee osteoarthritis. Osteoarthritis and cartilage. 2013;21(8):1042-52. DOI 10.1016/j.joca.2013.05.002 Source examined: Original article body retrieved.

Source note: SRC-d7dd25666a3f Dobson F 2013

2. Tolk JJ, Janssen RPA, Prinsen CSAC, van der Steen MMC, Bierma Zeinstra SMA, Reijman M. Measurement properties of the OARSI core set of performance-based measures for hip osteoarthritis: a prospective cohort study on reliability, construct validity and responsiveness in 90 hip osteo-arthritis patients. Acta orthopaedica. 2019;90(1):15-20. DOI 10.1080/17453674.2018.1539567 Source examined: Original article body and original supplementary PDF retrieved; supplementary Tables 2–4 visually checked.

Source note: SRC-daf9772081ef Tolk JJ 2019

3. Unver B, Kahraman T, Kalkan S, Yuksel E, Karatosun V, Gunal I. Test-retest reliability of the 50-foot timed walk and 30-second chair stand test in patients with total hip arthroplasty. Acta orthopaedica Belgica. 2015;81(3):435-41. PubMed. Source examined: Original publisher PDF retrieved; Table II and appendix visually checked.

Source note: SRC-cf3ec549527c Unver B 2015

4. Özden F, Coşkun G, Bakırhan S. The test-retest reliability and concurrent validity of the five times sit to stand test and step test in older adults with total hip arthroplasty. Experimental gerontology. 2020;142:111143. DOI 10.1016/j.exger.2020.111143 Source examined: Original abstract only; full article not retrieved.

Source note: SRC-30ef0036351f Ozden F 2020

5. Dobson F, Hinman R S, Hall M, Marshall C J, Sayer T, Anderson C, et al. Reliability and measurement error of the Osteoarthritis Research Society International (OARSI) recommended performance-based tests of physical function in people with hip and knee osteoarthritis. Osteoarthritis and cartilage. 2017;25(11):1792-1796. DOI 10.1016/j.joca.2017.06.006 Source examined: Original article body retrieved; numerical original tables incomplete in extraction; nonoperative mixed OA context.

Source note: SRC-55a59aa57129 Dobson F 2017

6. Abujaber SB, Marmon AR, Pozzi F, Rubano JJ, Zeni JA. Sit-To-Stand Biomechanics Before and After Total Hip Arthroplasty. The Journal of arthroplasty. 2015;30(11):2027-33. DOI 10.1016/j.arth.2015.05.024 Source examined: Original article body retrieved.

Source note: SRC-475b55ef97f3 Abujaber SB 2015

7. Abujaber S, Pozzi F, Zeni J. Influence of weight bearing visual feedback on movement symmetry during sit to stand task. Clinical biomechanics (Bristol, Avon). 2017;47:110-116. DOI 10.1016/j.clinbiomech.2017.06.005 Source examined: Original article body retrieved.

Source note: SRC-924cbcd1ad17 Abujaber S 2017

8. Esbjörnsson AC, Naili JE. Functional movement compensations persist in individuals with hip osteoarthritis performing the five times sit-to-stand test 1 year after total hip arthroplasty. Journal of orthopaedic surgery and research. 2020;15(1):151. DOI 10.1186/s13018-020-01663-0 Source examined: Original open-access full XML, including body and tables, retrieved.

Source note: SRC-0741e2016505 Esbjornsson AC 2020

9. Lippi L, Desimoni F, Canonico M, Massocco G, Turco A, Polverelli M, et al. System for Tracking and Evaluating Performance (Step-App®): validation and clinical application of a mobile telemonitoring system in patients with knee and hip total arthroplasty. A prospective cohort study. European journal of physical and rehabilitation medicine. 2024;60(2):349-360. DOI 10.23736/s1973-9087.24.08128-0 Source examined: Original article body retrieved; agreement figures not visually verified; mixed procedures/indications.

Source note: SRC-19e0ae8bbb16 Lippi L 2024

10. Gasparutto X, Gueugnon M, Laroche D, Martz P, Hannouche D, Armand S. Which functional tasks present the largest deficits for patients with total hip arthroplasty before and six months after surgery? A study of the timed up-and-go test phases. PloS one. 2021;16(9):e0255037. DOI 10.1371/journal.pone.0255037 Source examined: Original article body retrieved.

Source note: SRC-76ecfb3605f8 Gasparutto X 2021

11. Temporiti F, Zanotti G, Furone R, Loppini M, Molinari S, Zago M, et al. Functional and postural recovery after bilateral or unilateral total hip arthroplasty. Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology. 2019;48:205-211. DOI 10.1016/j.jelekin.2019.08.002 Source examined: Original abstract only; full article not retrieved.

Source note: SRC-83d400dd3ca6 Temporiti F 2019

12. Miura N, Tagomori K, Ikutomo H, Nakagawa N, Masuhara K. Asymmetrical loading during sit-to-stand movement in patients 1 year after total hip arthroplasty. Clinical biomechanics (Bristol, Avon). 2018;57:89-92. DOI 10.1016/j.clinbiomech.2018.06.017 Source examined: Original abstract only; full article not retrieved.

Source note: SRC-6238486b508a Miura N 2018

13. Miura N, Tagomori K, Ikutomo H, Nakagawa N, Masuhara K. Leg loading during quiet standing and sit-to-stand movement for one year after total hip arthroplasty. Physiotherapy theory and practice. 2018;34(7):529-533. DOI 10.1080/09593985.2017.1422203 Source examined: Original abstract only; full article not retrieved.

Source note: SRC-8f1c7382cbb6 Miura N 2018

14. Caplan N, Stewart S, Kashyap S, Banaszkiewicz P, St Clair Gibson A, Kader D, et al. The effect of total hip and hip resurfacing arthroplasty on vertical ground reaction force and impulse symmetry during a sit-to-stand task. Clinical biomechanics (Bristol, Avon). 2014;29(10):1164-9. DOI 10.1016/j.clinbiomech.2014.09.008 Source examined: Original abstract only; full article not retrieved.

Source note: SRC-57c6d682e479 Caplan N 2014

15. Lamontagne M, Beaulieu ML, Varin D, Beaulé PE. Lower-limb joint mechanics after total hip arthroplasty during sitting and standing tasks. Journal of orthopaedic research : official publication of the Orthopaedic Research Society. 2012;30(10):1611-7. DOI 10.1002/jor.22127 Source examined: Original abstract only; full article not retrieved.

Source note: SRC-7ebc4df07495 Lamontagne M 2012

16. Talis VL, Grishin AA, Solopova IA, Oskanyan TL, Belenky VE, Ivanenko YP. Asymmetric leg loading during sit-to-stand, walking and quiet standing in patients after unilateral total hip replacement surgery. Clinical biomechanics (Bristol, Avon). 2008;23(4):424-33. DOI 10.1016/j.clinbiomech.2007.11.010 Source examined: Original abstract only; full article not retrieved.

Source note: SRC-7a15c7b8fd2f Talis VL 2008

17. Wang J, Siddicky SF, Dohm MP, Barnes CL, Mannen EM. Kinematic and Kinetic Changes after Total Hip Arthroplasty during Sit-To-Stand Transfers: Systematic Review. Arthroplasty today. 2021;7:148-156. DOI 10.1016/j.artd.2020.12.026 Source examined: Original article body retrieved.

Source note: SRC-c10004a5d4ba Wang J 2021

18. Almonroeder TG, Sackiriyas KSB, Hyoda H, Yennu A, Abujaber S. Weight-bearing asymmetry during sit-to-stand following total hip arthroplasty: A scoping review. Musculoskeletal science & practice. 2025;80:103419. DOI 10.1016/j.msksp.2025.103419 Source examined: Original abstract only; full article not retrieved.

Source note: SRC-6854c2678dc4 Almonroeder TG 2025

19. M'barki H, Lavoie-Hudon A, Gagnon M, Turcot K, Belzile EL. Biomechanical Assessment of Functional Tasks Beyond Level Walking Following Total Hip Arthroplasty: A Scoping Review. Journal of orthopaedic research : official publication of the Orthopaedic Research Society. 2026;44(7):e70245. DOI 10.1002/jor.70245 Source examined: Original abstract only; full article not retrieved.

Source note: SRC-b5df9c285fa4 Mbarki H 2026

20. Kawano T, Nankaku M, Murao M, Goto K, Kuroda Y, Kawai T, et al. Development of a Clinical Prediction Rule to Identify Physical Activity After Total Hip Arthroplasty. Archives of physical medicine and rehabilitation. 2022;103(10):1975-1982. DOI 10.1016/j.apmr.2022.03.015 Source examined: Original abstract only; full article not retrieved.

Source note: SRC-26a83e470153 Kawano T 2022

21. Christensen JC, Judd DL, Thomsen-Freitas PB, Davis-Wilson H, Christiansen CL, Stevens-Lapsley JE. Kinetic Biomarkers of Cumulative Loading and Daily Step Count as Predictors of Functional Recovery Following Primary Unilateral Total Hip Arthroplasty. Journal of orthopaedic research : official publication of the Orthopaedic Research Society. 2026;44(5):e70203. DOI 10.1002/jor.70203 Source examined: Original abstract only; full article not retrieved.

Source note: SRC-b9e40de78da0 Christensen JC 2026

22. Jeldi AJ, Deakin AH, Allen DJ, Granat MH, Grant M, Stansfield BW. Total Hip Arthroplasty Improves Pain and Function but Not Physical Activity. The Journal of arthroplasty. 2017;32(7):2191-2198. DOI 10.1016/j.arth.2017.02.002 Source examined: Original abstract only; full article not retrieved.

Source note: SRC-1e73689ae4a0 Jeldi AJ 2017