Changes in Subjects With Posterior Capsule Tightness: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Changes in Subjects With Posterior Capsule Tightness (NCT02353442), a randomized na study. The primary outcome is Scapular Kinematics at 4weeks (Pre and Post Treatment).

2. Clinical Question

3. Trial Design

The registry describes a randomized, triple-masked, parallel-group study with an enrollment of 59. The record lists a control group and an experimental group. Participants were assigned to one of these groups, but the method used to generate the random sequence and conceal assignments is not reported in the registry record. The record identifies the study as completed and lists its phase as not applicable.

The control group was assigned four weeks of placebo ultrasound, scapular squeezing in a sitting position, and upper trapezius stretching in a sitting position. The described ultrasound lasted 5 minutes. Scapular squeezing is described as 3x10 repetitions; stretching is described as 3x30s with 30s of rest. The experimental group was assigned four weeks of posterior shoulder mobilizations, external rotators strengthening in a sidelying position with load, and posterior capsule stretching. The mobilizations are described as 5 minutes, with 30s of mobilization and 30s of rest; the strengthening is described as 3x10 repetitions. The description of the stretching ends after 3x30s and 3, so its remaining details are not reported in the registry record.

Triple masking is listed, but the roles masked, the method of masking, and whether masking was maintained are not reported in the registry record. Recruitment procedures, eligibility criteria, study locations, adherence, and treatment fidelity are also not reported. The primary outcome is measured at baseline and four weeks. Secondary outcomes concern external-rotator strength, pressure pain threshold, and pain and function at four weeks. The record does not provide results for these outcomes or explain the planned statistical comparisons.

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

Reasons for not completing this period:

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.

6. Primary Endpoint

The registry lists the primary outcome as Scapular Kinematics at 4weeks (Pre and Post Treatment), measured over 4 weeks: Baseline (pre-treatment), and 4 weeks (post-treatment).

The primary outcome is scapular kinematics at baseline and four weeks after treatment. It is assessed in degrees using a three-dimensional system, and the registry describes the measure as a mean with standard error as its dispersion. Scapular kinematics concern movement of the shoulder blade. Such measurements can describe a biomechanical feature of shoulder movement; the registry record does not specify the exact kinematic variables or how they are derived from the three-dimensional assessment.

The outcome is relevant to the study’s stated aim of identifying biomechanical changes in people with posterior capsule tightness. A pre-treatment and post-treatment measure can describe change over the treatment period. To assess whether change differs between the assigned groups, an analysis would need to compare the groups’ outcome patterns, accounting for the repeated measurements on participants. The registry record does not report the analysis method or the primary outcome values, so neither the direction nor the magnitude nor the precision of any between-group difference can be described.

Standard error describes the precision of an estimated mean, rather than the spread of individual participants’ measurements. As a general statistical point, a small standard error does not imply that individual measurements are closely grouped; it reflects uncertainty in the estimated mean and depends on both variability and the amount of information contributing to that estimate. The registry record does not give a numerical mean, standard error, confidence interval, or comparison for the primary outcome.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a randomized, triple-masked, parallel-group design. Random allocation is intended to prevent systematic assignment based on participant or investigator characteristics. As a general statistical principle, this can support a causal comparison when the assigned groups are analyzed appropriately, but it does not remove the need to report how allocation was implemented, what happened after assignment, and how outcomes were analyzed. The record does not describe the sequence-generation method or allocation concealment. It also does not identify who was masked or how masking was maintained.

What does the mean describe?

The primary outcome is a continuous measurement in degrees, summarized as a mean. A mean gives a single measure of the central level of observations, but it does not show the full distribution. Participants can vary around the mean, and the distribution may include unusual values or have a shape that matters for analysis. The registry record does not provide individual observations, group means, or a description of the distribution. It is therefore not possible to assess whether the mean is a complete or adequate description of the outcome in this study.

What does standard error describe?

The record specifies standard error as the dispersion accompanying the mean. As a general statistical explanation, standard error represents the sampling uncertainty of an estimated mean, whereas standard deviation describes variation among individual observations. These quantities answer different questions and should not be treated as interchangeable. A confidence interval combines an estimate with its uncertainty to show a range of values compatible with the data under the analysis assumptions. No standard errors or confidence intervals for the primary outcome are reported in the registry record, so its precision cannot be evaluated.

How should repeated measurements be considered?

The primary outcome is assessed before treatment and at four weeks. These repeated measurements are taken from the same participant, so they are related rather than independent. As a general statistical point, an analysis should account for that within-participant relationship. Possible approaches include comparing change from baseline between groups or modeling measurements over time; the appropriate choice depends on the study design, data, and analysis plan. The registry record does not report which approach was used, whether baseline values were adjusted for, or whether a group-by-time contrast was estimated. No such analysis should be assumed from the outcome description alone.

A comparison of post-treatment means and a comparison of changes from baseline are not automatically identical, especially when baseline values differ. A prespecified analysis can clarify which contrast answers the main question and limit the risk of selecting a result after seeing the data. The analysis plan and the estimated contrast are not reported in the registry record. Thus, it is not possible to determine whether the posted analysis, if any, followed a prespecified approach.

Why do uncertainty and assumptions matter?

An effect estimate describes the size and direction of a comparison, while its uncertainty indicates how much the estimate could vary because of sampling. A p-value, if reported, would address compatibility with a specified null model under statistical assumptions; it would not measure the probability that a treatment is effective or establish the clinical importance of an effect. Neither an effect estimate, a confidence interval, nor a p-value for the primary outcome is reported. Statistical significance therefore cannot be evaluated.

For continuous outcomes, methods based on normal approximations may be reasonable in some settings, but their adequacy depends on the data and model. As a general point, skewness, outliers, unequal variability, or departures from model assumptions can affect estimates and uncertainty. The record does not provide distributions, diagnostics, or model details. It does not report adjustments for baseline covariates or describe whether analyses were adjusted or unadjusted.

The record contains a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The illustration considers effects expressed as a fraction of the observed effect. Such calculations describe hypothetical planning scenarios under stated assumptions; they are not evidence that the trial had a particular probability of detecting an effect, and they are not observed power. The record does not report the trial’s own sample-size justification. A planning estimate based on an observed effect is also sensitive to the uncertainty of that observed effect, so it should not be treated as a reliable description of what the study was designed to detect.

In general, over-dispersion means that observed variability is greater than a model assumes. If ignored, uncertainty estimates may be too small, making results appear more precise than they are. This is a general concept rather than a reported feature of this study: the primary outcome is continuous, and the registry record does not report evidence of over-dispersion or a model for which it was assessed. More broadly, statistical methods should match the outcome type and design, but no method can be inferred from the endpoint description alone.

Because the posted record gives no analyzed group estimates or analysis details, the methods concepts describe what would be relevant to interpret a comparison, not what the investigators actually did. The statistical plan, handling of repeated measures, model checks, treatment of outliers, and adjustment strategy are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary outcome and three secondary-outcome descriptions. The primary outcome is scapular kinematics at baseline and four weeks. Secondary outcomes concern external-rotator strength, pressure pain threshold, and pain and function at four weeks. The record does not report whether each secondary outcome has one measure or multiple measures, how many comparisons were planned, or whether any correction for multiple testing was used.

As a general statistical point, assessing several outcomes or time points can increase the chance that at least one result appears statistically notable by chance. Prespecifying a primary outcome and analysis can help keep the main inference clear. The record identifies a primary outcome, but does not describe a hierarchy among outcomes, a multiplicity adjustment, or rules for selecting outcome variables. No interim analyses or stopping rules are reported in the registry record.

Missing-data amounts, reasons for missingness, and methods for handling missing observations are not reported. The record also does not identify an analysis population, such as whether participants were analyzed according to randomized assignment, or whether any participants were excluded from analyses. As a general matter, missingness can affect both the estimate and its uncertainty, particularly when the likelihood of a missing measurement is related to the outcome or treatment group. Without the amount, pattern, and treatment of missing data, the robustness of any result cannot be assessed.

The registry record does not report whether analyses were prespecified, how deviations from the protocol were handled, or whether sensitivity analyses were conducted. These omissions limit interpretation of the analysis process; they do not, on their own, establish that analyses were inappropriate.

11. Safety Results

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

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The adverse-event entry lists zero serious adverse events and zero other adverse events in the control group, with 28 participants at risk. For the experimental group, it lists zero serious adverse events and zero other adverse events, with 31 participants at risk. These are the event counts recorded for the groups; the registry record does not give event terms, and it lists no serious-event terms.

Zero recorded events should be read narrowly. It means that no events of the specified types are listed for these groups in this record. It does not establish that no symptoms or events occurred, that all events were collected, or that the interventions have no risks. The definitions used for serious and other adverse events, the duration of safety monitoring, how events were solicited, and whether reporting was complete are not reported in the registry record. Death counts are listed as null, rather than as a numerical count, so deaths cannot be interpreted as a reported zero.

As a general statistical point, event counts are more informative when accompanied by clear definitions, observation periods, and a complete account of follow-up. The registry entry does not provide those details. The recorded figures therefore describe the available safety reporting, not a comprehensive estimate of safety.

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

The record establishes that a randomized, triple-masked, parallel-group study was conducted in people described as having posterior capsule tightness, including people with and without shoulder pain. It identifies a four-week experimental program and a four-week control program, and names scapular kinematics measured before and after treatment as the primary outcome. These are design and measurement details, not evidence of an outcome.

The result that matters for the main comparative question would include a between-group estimate for the primary outcome, its uncertainty, and an explanation of the analysis. Those results are not reported in the registry record. The direction and magnitude of any difference, and the precision with which it was estimated, therefore remain unknown from this record. The same limitation applies to the listed secondary outcomes: their descriptions are present, but their numerical findings are not.

As a general statistical point, a non-significant result, if one were reported, would not by itself show that groups were equivalent. Evidence of equivalence or non-inferiority requires an appropriate design, a prespecified margin, and analyses aligned with that question. None of these are reported in the registry record. In this case, no significance result is reported at all, so it would be inaccurate to describe the study as finding either a difference or no difference.

Likewise, a change over time within one group would not by itself establish that the assigned program caused that change. A randomized comparison is intended to evaluate differences between assigned groups, but the analysis must preserve the comparison and account for relevant features of the design. The registry record does not provide outcome estimates, the analysis population, or methods for missing data, so those aspects cannot be evaluated.

The adverse-event entry reports zero serious and zero other adverse events in each group, with different risk counts recorded for each. These figures should not be extended into a broad safety conclusion because event definitions, monitoring, and completeness are not described. The record is therefore useful for understanding the research question and intended comparison, but it does not provide enough result information to judge the comparative outcome or its clinical importance.

13. Why This Trial Matters Statistically

This study is statistically interesting because its question connects a biomechanical measure with a randomized comparison of two different four-week programs. The primary outcome is scapular kinematics, assessed with a three-dimensional system and expressed in degrees. The design also includes measures of external-rotator strength, pressure pain threshold, pain, and function. Together, these outcomes indicate that the registry sought to describe more than one aspect of shoulder-related change, although it does not report their numerical results.

The combination of baseline and post-treatment measurement raises familiar analysis questions. Repeated observations on the same participant are related, and the comparison of interest concerns how outcomes differ between assigned groups over time. A clear report would identify the contrast, explain how baseline measurements were handled, and present an estimate with uncertainty. Those details are not reported in the registry record, making the study a useful example of why outcome descriptions alone do not allow readers to evaluate a treatment comparison.

The record also illustrates the difference between a registered study and a complete results account. Randomization, masking, group descriptions, and outcome definitions help readers understand intended methods. Without group results, analysis details, and information about missing observations, however, it is not possible to assess effect size, precision, or robustness. Registration information and results reporting serve complementary roles; neither can replace the other.

Finally, the adverse-event entry demonstrates why a zero count requires context. The record lists zero events, but does not explain the event definitions, monitoring period, or reporting completeness. A count alone cannot support a broad inference about safety. These reporting considerations apply generally and are especially important when readers need to distinguish what a trial measured from what its data can substantiate.

14. 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 registry record does not report numerical results for the primary outcome or the listed secondary outcomes. It therefore does not permit assessment of effect direction, magnitude, precision, or statistical significance. The record also lists no statistical analyses, leaving the comparison method and any model assumptions unclear.

Several design details needed to evaluate potential bias are not reported: eligibility criteria, recruitment procedures, the random-sequence method, allocation concealment, and which people were masked. Although the design is listed as triple-masked, the record does not identify the masked roles or describe how masking was implemented. Participant characteristics and the distribution of shoulder pain status are also not reported.

The experimental stretching description is incomplete, ending after 3x30s and 3. The record does not report adherence, treatment fidelity, concomitant care, or the full measurement procedures for the kinematic outcome. The specific scapular variables assessed with the three-dimensional system are not described.

Missing-data amounts and handling, analysis populations, multiplicity procedures, and any interim analyses are not reported in the registry record. The safety entry lacks event definitions, monitoring duration, and details on completeness; deaths are listed as null rather than as a count. These limitations constrain interpretation of both outcomes and safety. They identify what cannot be evaluated from the registry record and should not be taken as proof that the study did or did not address these matters elsewhere.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Changes in Subjects With Posterior Capsule Tightness — NCT02353442.
• Registry record last updated 2017-03-21; status last verified 2017-02.
• Results first posted 2017-02-15.
• 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.

18. Record Summary

The registry describes a completed, randomized, triple-masked, parallel-group study with an enrollment of 59. It concerns people with posterior capsule tightness, with and without shoulder pain. The control group was assigned placebo ultrasound, scapular squeezing, and upper trapezius stretching; the experimental group was assigned posterior shoulder mobilizations, external rotators strengthening, and posterior capsule stretching, over four weeks.

The primary outcome is scapular kinematics in degrees, measured with a three-dimensional system at baseline and four weeks and described as a mean with standard error. Secondary outcomes concern external-rotator strength, pressure pain threshold, and pain and function. Numerical outcome results and statistical analyses are not reported in the registry record. The adverse-event entry lists zero serious and zero other adverse events in each group, but does not provide the monitoring and reporting details needed for a broad safety interpretation.