Active Versus Passive Motion Device Following Knee Replacement Surgery: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Active Versus Passive Motion Device Following Knee Replacement Surgery (NCT02339831), a randomized na study. The primary outcome is Early Functional Outcome Strength.

2. Clinical Question

The registry record describes a prospective, controlled comparison at a single center. It does not report the allocation concealment process, eligibility criteria in detail, or a prespecified definition of a clinically important strength difference. The main comparison therefore addresses the observed group averages at the stated follow-up, rather than establishing whether any difference would be meaningful to patients or applicable to other settings.

3. Trial Design

The registry identifies this as a prospective, randomized, controlled, single-center study of CAMOPED following knee replacement. The design is parallel: participants were assigned to an active-motion device or a passive-motion device, with no masking. The record lists the phase as NA, the study status as completed, and an enrollment of 110. Its recorded study dates run from 2007-03 to primary completion in 2010-12.

Participants undergoing partial or total knee replacement could elect to participate, according to the brief study description. The record says preoperative information was to include demographics, strength, balance, knee bending, and health and knee-function surveys. Following surgery, participants were randomly selected to receive one of the two devices. The active device was used for 3 sessions of 20 minutes for 3 weeks; the passive device was used for 4 hours daily for 3 weeks. After discharge, participants were asked to record device use and daily pain in a diary.

The study description says a follow-up visit was planned 4 weeks after surgery, with surveys and tests of strength, balance, and knee bending. The primary outcome’s registry timeframe is stated as 4-6 weeks post-op, so those are the timing terms attached to the posted result. The primary outcome summary includes 38 participants for the active device and 45 for the passive device. The registry record does not explain how those outcome counts relate to its recorded enrollment of 110, or provide a participant-flow account.

Randomization can reduce systematic baseline differences on average, but the record does not report details of the sequence generation or allocation concealment. Because masking is listed as none, participants and study personnel were not masked according to the registry record. No original sample-size justification, detailed statistical analysis plan, or interim-analysis plan is reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

Population: 137 patients agreed to participate, 27 did not meet the inclusion criteria and 110 signed the informed consent form. Following allocation to their group, we excluded 24 patients (20 using CAM and 7 CPM) who did not finish the study due to non-compliance, leaving a total of 83 patients.

6. Primary Endpoint

The registry lists the primary outcome as Early Functional Outcome Strength, measured over 4-6 weeks post-op.

The primary endpoint is described as “Early Functional Outcome Strength.” It measures quadriceps strength using a hand-held dynamometer, with results expressed in newton meter. The registry record reports a mean and standard deviation for each device group, with the outcome timeframe given as 4-6 weeks post-op. This is a continuous outcome: each participant’s measurement can take a range of values, and the group mean describes its average level.

Quadriceps strength is one measure of physical function after knee replacement. In the study description, strength testing was part of a broader assessment that also included balance, knee bending, surveys about health, and knee-function measures. The endpoint was used to compare early strength outcomes between participants assigned to active motion and those assigned to passive motion. It does not, by itself, represent every aspect of recovery or establish how participants felt about their function.

The registry record does not define a threshold for a meaningful difference in this strength measure, nor does it state whether the endpoint was adjusted for preoperative strength or other characteristics. The posted group summaries and unadjusted comparison therefore describe the observed early strength results as recorded, without establishing a change from baseline or an adjusted treatment effect.

7. Results Posted in the Registry

• Passive Motion Device: mean 11.60 versus 12.02 on control; difference -0.42 (95% CI -2.24 to 1.40), standardized effect d = -0.10; z-test p = 0.652.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

General Mental Orthopaedic Outcome Measures

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Passive Motion Device: mean 39.40 versus 40.20 on control; difference -0.80 (95% CI -4.48 to 2.88), standardized effect d = -0.09; z-test p = 0.670.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Passive Motion Device and the control. The interval gives the range of effects that remain compatible with the data.

General Activity Orthopaedic Outcome Measures

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Passive Motion Device: mean 50.20 versus 45.80 on control; difference 4.40 (95% CI -2.16 to 10.96), standardized effect d = 0.28; z-test p = 0.189.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Passive Motion Device and the control. The interval gives the range of effects that remain compatible with the data.

General Functional Orthopaedic Outcome Measures

• Endpoint type: Continuous: a mean value per participant, compared as a difference in means.
• Test: Unadjusted two-sample z-test for the difference in means, using the posted standard deviations.
• Result:
  • Passive Motion Device: mean 62.60 versus 64.70 on control; difference -2.10 (95% CI -9.58 to 5.38), standardized effect d = -0.12; z-test p = 0.582.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Passive Motion Device and the control. The interval gives the range of effects that remain compatible with the data.

The posted secondary outcomes cover general mental, activity, and functional orthopaedic outcome measures, along with general pain listed among the secondary outcomes. The three posted scale outcomes have group means and standard deviations at 4-6 weeks post-op. Their recalculated unadjusted comparisons do not show a uniform directional pattern: the passive-motion mean is lower for some measures and higher for another. The intervals for these comparisons include zero.

This overall pattern does not materially change the interpretation of the primary strength result. These measures describe related but distinct dimensions of early recovery; they are not substitutes for quadriceps strength and cannot establish the result for the primary endpoint. Nor do the posted secondary summaries establish a broad advantage for either device. Their unadjusted nature, uncertainty, and separate outcome domains all matter when considering them alongside the primary result.

The registry record lists 9 outcome measures, while 4 secondary outcomes are posted. The record reports no analyses for the secondary outcomes. The presence of multiple outcomes creates a multiplicity concern: when many outcomes are examined, the chance of at least one apparently unusual result can increase, even if no true differences exist. A prespecified hierarchy or adjustment can help address this, but the registry record does not report whether any such approach was planned or used.

For that reason, secondary results generally carry less confirmatory weight than a clearly prespecified primary comparison, particularly when no multiplicity plan is reported. They can still describe the available data and suggest questions for further study, but they should not be treated as independent proof of a device effect. The record does not provide a complete analysis plan or enough information to determine how the secondary outcomes were selected, prioritized, or interpreted by the investigators.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• General Mental Orthopaedic Outcome Measures
• General Activity Orthopaedic Outcome Measures
• General Functional Orthopaedic Outcome Measures
• General Pain

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is continuous, so it is described using a mean and a standard deviation in each group. The mean locates the group’s average measured strength. The standard deviation describes how spread out the individual measurements are around that average. It is not the uncertainty in the mean itself and does not show the full distribution of participants’ values.

The comparison is a mean difference. Its direction is defined as the passive-motion mean minus the active-motion mean. A value below zero therefore corresponds to a lower observed average in the passive-motion group; a value above zero corresponds to a higher observed average in that group. The difference is an absolute contrast in the endpoint’s units, not a percentage or a relative effect.

The posted comparison is an unadjusted recalculation from group summary statistics. That means it compares the reported group means without accounting for participant-level characteristics such as baseline strength. An adjusted analysis could account for prespecified covariates, but the registry record does not report such an analysis for this outcome. It also does not provide participant-level data from which to examine the shape of the measurements, outliers, or alternative models.

A confidence interval gives a range of values reasonably compatible with the estimated difference under the statistical method and its assumptions. It conveys uncertainty in the estimate, rather than the range containing most individual participants’ measurements. A 95% confidence interval is constructed by a procedure that, under its assumptions, would capture the true parameter in 95% of repeated applications. It is not a statement that there is a 95% probability that the particular interval contains the true effect.

The unadjusted p-value evaluates how incompatible the observed data are with a null model of no group difference, subject to the analysis assumptions. It is not a measure of effect size, clinical importance, or the chance that the result arose “by chance.” A larger p-value does not demonstrate equivalence. The registry record does not report a formal hypothesis-testing plan, a clinically meaningful difference, or a decision rule for interpreting the p-value.

Standard deviations and sample sizes influence the precision of a mean comparison: greater variability and fewer observations generally make estimates less precise. Standard errors quantify the uncertainty of an estimated mean or contrast, rather than variation among individual measurements. The reported group standard deviations, outcome counts, and interval should be read together; none alone fully describes the comparison.

There are several distinctions between the trial’s record and the recalculated statistical summaries. The record gives the overall enrollment as 110, while the primary outcome summaries list 38 participants in the active-motion group and 45 in the passive-motion group. These are not interchangeable quantities. The registry record does not explain the participant flow, the reasons outcome data are absent for other enrolled participants, or whether the outcome counts reflect exclusions, missing measurements, or another process. No inference about those reasons is warranted from the summaries alone.

What does “unadjusted” mean?

An unadjusted mean difference uses the group summaries without accounting for other variables. Random allocation can support a fair comparison, but it does not make an unadjusted result identical to a baseline-adjusted result. The record does not report baseline strength by group alongside the endpoint, and it does not report the sponsor’s statistical model. The recalculated contrast is consequently best read as a straightforward comparison of posted averages.

Why does the outcome scale matter?

The endpoint is reported in newton meter, so the mean difference is expressed on the same measurement scale. A confidence interval in the original units can be considered alongside subject-matter knowledge about what changes are important. However, the registry record does not provide a clinically important threshold for this measure. Without such a threshold, the statistical summary alone cannot classify the observed contrast as important or unimportant to participants.

What can the p-value establish?

The p-value is a measure of compatibility between the data and a null model under specified assumptions. It is not proof for or against a treatment effect. The registry record does not report whether the primary comparison was prespecified in a detailed statistical plan, how missing outcome data were handled, or whether any covariate adjustments were intended. The posted p-value should therefore be understood as the unadjusted value associated with the recalculated summary comparison, rather than as a complete account of the trial’s planned analysis.

More generally, a randomized trial’s interpretation depends on the treatment contrast, the measurement process, the participants included in the analysis, and the follow-up timing. In this study, the assigned devices differed in both mode of motion and stated usage schedule. The observed comparison is therefore between the assigned rehabilitation regimens as described, not an isolated test of device mechanics under identical use. The record does not report adherence summaries or the diary results, so the degree to which participants followed the stated schedules is not available for interpretation.

11. Confidence Intervals and Precision

The primary mean difference is -0.42 newton meter, with a 95% confidence interval from -2.243 to 1.403. The interval is the clearest summary of the estimate’s statistical precision: it includes zero and allows values on either side of no difference. It also indicates that the observed data do not pin down the direction of the group contrast with high precision.

The interval is not a range of individual strength measurements, and it does not imply that every value inside it is equally plausible. It reflects sampling uncertainty under the calculation’s assumptions. The group standard deviations of 4.12 and 4.34 describe participant-to-participant spread, whereas the interval describes uncertainty in the estimated difference between group means. These quantities answer different questions.

Precision is also distinct from clinical importance. The registry record does not identify a threshold for a meaningful change in quadriceps strength, so the confidence interval cannot be judged against such a threshold. A result can be statistically imprecise without being clinically unimportant, and a narrow interval would not by itself establish clinical importance. Interpretation requires a relevant threshold or context that is not reported in the registry record.

The comparison is based on the posted outcome counts of 38 and 45. The registry record does not report why these counts differ from the recorded enrollment, whether missing measurements were present, or how missingness was handled. Those details matter because the confidence interval quantifies uncertainty under its statistical assumptions; it does not correct for bias that could arise if the observed participants differ systematically from those without outcome data.

The interval is a recalculated unadjusted summary. It does not reflect additional uncertainty from unreported design choices, missing-data procedures, or multiple outcome testing. The record reports no sponsor analysis for this comparison and no multiplicity strategy. These limits do not invalidate the numerical interval, but they constrain how completely it represents uncertainty about the trial’s broader conclusions.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The planning figures are participants per arm, not total events. They are illustrative calculations based on the observed effect, not the trial’s original design assumptions. The stated calculation assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, a normal approximation, and an effect to detect equal to a stated fraction of the observed effect.

The 80% power column gives the number of participants per arm that the planning calculation estimates would be needed for an 80% chance of detecting the specified effect under those assumptions, if that effect were the true one and the model assumptions held. The 90% power column uses a higher target chance of detection, so its planning count is larger. Power is a property of a planned study under specified assumptions; it does not describe the probability that a particular result is correct.

For each outcome, the planning rows consider detecting 100%, 75%, or 50% of the observed effect. A smaller target effect is harder to distinguish from random variation, so the calculation requires more participants per arm. The entries are not observed trial counts, nor are they evidence that the completed study had a particular probability of detecting an effect.

These figures use an effect estimated from the posted trial summaries. Such estimates can be unstable, particularly when the observed effect is small, and planning calculations based on them are not guarantees for a future study. The registry record does not report the original sample-size justification, its target effect, or its original power assumptions; only the assumptions for this planning illustration are known. This is not observed power.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.

Worked calculation for this trial

1. Observed difference Δ = -0.420; pooled standard deviation σ = 4.241.
2. n = 2 × (1.96 + 0.842)² × 4.241² / -0.420² = 1,600.5, rounded up to 1,601 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
delta <- -0.42                      # observed difference in means
sigma <- 4.24092233154796                     # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
  ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")

# Simulation: exact two-sample t-test using simulated means and variances
set.seed(2339831)
n    <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n))             # difference in sample means
s2     <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1))   # pooled sample variance
tstat  <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))

Output from running the code

100% of observed effect: n per arm = 1,601 (80% power), 2,143 (90% power)
 75% of observed effect: n per arm = 2,846 (80% power), 3,810 (90% power)
 50% of observed effect: n per arm = 6,403 (80% power), 8,571 (90% power)
power.t.test: 1601.5 
Simulated power at n = 1,601 per arm: 0.802 (20000 replicates)

The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Multiplicity, Missing Data and Analysis Populations

The registry record lists 9 outcome measures and identifies several secondary outcomes, but it does not report a multiplicity adjustment, a testing hierarchy, or another method for controlling the interpretation of multiple comparisons. When many outcomes are tested, the chance of observing at least one apparently notable result can rise. This is why secondary comparisons are usually interpreted more cautiously unless their role and analysis plan were specified in advance. The absence of a reported strategy does not show that no strategy existed; it means the strategy is not reported in the registry record.

The posted summaries give outcome counts for the primary measure and for the three secondary scale outcomes. The registry record does not describe participant flow or explain the relationship between those outcome counts and the recorded enrollment of 110. It does not report the amount or pattern of missing outcome data, reasons for missingness, or any imputation or other missing-data method. The summaries alone cannot show whether missingness was related to participants’ health, device use, or outcomes.

The record also does not define the analysis population for the comparisons. It is not reported whether analyses followed an intention-to-treat principle, included only participants with available measurements, or used another population definition. The observed outcome counts should therefore be read as the counts attached to the posted summaries, not as evidence of a particular analysis population.

These reporting gaps matter because the validity of a comparison can depend on who is included and how incomplete data are handled. Randomization concerns assignment, but missing outcomes after assignment can affect the comparability of the analyzed groups. The registry record does not provide enough information to determine whether this occurred. It also does not report a detailed statistical analysis plan, so the prespecification of outcome definitions, model choices, or handling of multiple endpoints cannot be assessed.

15. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

The registry’s adverse-event summaries report zero serious adverse events among 38 participants at risk in the active-motion group and zero among 45 participants at risk in the passive-motion group. The summaries also report zero other adverse events in each group, with the same group-specific numbers at risk. Deaths are reported as zero in both groups. No serious adverse-event terms are listed.

These figures describe what the registry record reports for the displayed groups; they do not establish that no events occurred outside the recorded categories or observation period. The record does not provide detailed event definitions, monitoring procedures, follow-up duration for safety, or an explanation of the relationship between the safety counts and the overall enrollment. Zero reported events should not be interpreted as proof that either device has no risk. The summaries are descriptive, and the available record does not support a broader comparative safety conclusion.

16. What the Result Does, and Does Not, Mean

The posted results describe early outcomes after knee replacement among participants assigned to an active-motion device or a passive-motion device. For the primary strength endpoint, the group means are close in the observed summaries, and the recalculated unadjusted confidence interval includes zero. The result does not establish that the devices are equivalent, because no equivalence margin or noninferiority framework is reported. It also does not establish that one device is superior.

The interpretation is limited to quadriceps strength at the stated 4-6 weeks post-op timeframe and to the participants represented in the outcome summaries. The study description includes other aspects of recovery, such as balance, knee bending, pain, and health or function surveys, but an individual outcome cannot stand in for all of these domains. The secondary summaries also do not provide a basis for a definitive overall comparison, particularly without a reported multiplicity strategy.

The study compares assigned rehabilitation regimens that differ in both device type and stated usage schedule. It therefore does not isolate a single mechanical feature of the devices. The registry record does not report adherence results, so it is not possible to determine whether actual device use matched the stated schedules or how use related to outcomes.

The recorded enrollment is 110, while the primary outcome summaries include 38 and 45 participants by group. The registry record does not explain the participant flow or the handling of missing outcome data. As a result, the posted means and their recalculated interval should not be taken as a complete account of every enrolled participant’s outcome. The record also does not report the original statistical plan, a clinically meaningful difference, or adjusted analyses.

These findings are a description of the posted data, not medical advice or a recommendation about rehabilitation choices. They do not establish outcomes beyond the reported follow-up, apply automatically to settings beyond the single center, or settle questions about longer-term recovery. The numerical estimate, its uncertainty, and the registry’s reporting gaps should be considered together.

17. Why This Trial Matters Statistically

This trial is statistically instructive because it pairs a randomized comparison with a continuous functional endpoint and a short-term assessment after knee replacement. The mean difference is easy to express in the measurement’s original units, while the confidence interval shows why a single estimate should not be read as a definitive conclusion. The interval spans zero and values in either direction, so the result is more informative when its uncertainty is considered than when attention is limited to the point estimate or p-value.

The record also illustrates the distinction between overall enrollment and outcome-specific counts. Enrollment is listed as 110, but the primary outcome summaries use group counts of 38 and 45. Without participant-flow information, a reader cannot determine why those counts differ or assess the potential effect of missing outcomes. Clear reporting of analysis populations and missing-data handling is central to interpreting randomized trials, not merely a technical detail.

Another important issue is multiplicity. Several secondary outcome domains are present, but no analysis results or multiplicity strategy are reported for them. A broad set of endpoints can offer a richer view of recovery, yet it also requires transparent plans for prioritizing and interpreting comparisons. Without those details, secondary findings should be treated as descriptive rather than as a collection of independent confirmations.

Finally, planning calculations based on an observed effect are different from the trial’s original design justification. The registry record does not report the original assumptions. Illustrative planning figures can show how detectable effects and participant counts relate under stated assumptions, but they cannot retrospectively establish the completed study’s power or validate a conclusion. These distinctions make transparent reporting of estimates, intervals, analyses, and design choices essential to sound clinical interpretation.

18. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The available record leaves several trial-specific uncertainties. It identifies a single-center study, but does not report detailed eligibility criteria, participant characteristics, baseline strength by group, or the randomization and allocation concealment procedures. Those omissions limit assessment of how comparable the assigned groups were and how well the study population represents other settings or patients.

The primary endpoint is reported at 4-6 weeks post-op, while the study description refers to a visit 4 weeks after surgery. The record does not clarify the exact timing of measurements for each participant. It also does not report the original analysis plan, whether the primary comparison was adjusted for baseline measures, or the definition of the analysis population.

Outcome summaries include fewer participants by group than the recorded enrollment, and no participant-flow account explains the relationship. Missing-data amounts, reasons, and handling are not reported. Adherence to the different device schedules is also not reported, despite the study description’s mention of daily diaries. Consequently, the posted comparisons cannot establish whether the observed outcomes reflect the assigned regimens as intended or how incomplete follow-up may have affected the results.

The record does not report a clinically meaningful threshold for quadriceps strength, a multiplicity approach, or sponsor analyses of the posted secondary outcomes. The findings therefore lack important context for judging clinical importance and confirmatory evidence. Safety information is also limited to group counts of reported events, without detailed definitions or monitoring information. These limitations concern what can be concluded from the registry record; they do not establish that the study lacked procedures or analyses that are simply not reported there.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Active Versus Passive Motion Device Following Knee Replacement Surgery — NCT02339831.
• Registry record last updated 2017-03-20; status last verified 2017-01.
• Results first posted 2017-03-20.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

22. Record Summary

NCT02339831 is a completed, randomized, open-label, parallel, single-center study comparing CAMOPED active motion with a continuous passive motion device after partial or total knee replacement. The record lists enrollment of 110 and primary completion in 2010-12. The primary outcome is quadriceps strength measured with a hand-held dynamometer at 4-6 weeks post-op.

The posted primary summaries report means of 12.02 newton meter in the active-motion group and 11.6 in the passive-motion group. The recalculated unadjusted mean difference is -0.42, with a 95% confidence interval from -2.243 to 1.403 and an unadjusted p-value of 0.652. Secondary outcome summaries cover mental, activity, and functional measures; no secondary analyses are reported in the registry record.

The record does not report the original sample-size justification, detailed statistical plan, participant flow, missing-data handling, or multiplicity strategy. Adverse-event summaries list zero serious events, zero other events, and zero deaths in both groups. These results describe the posted record and do not establish equivalence or superiority.