Serial Movement Assessment in Collegiate Athletes Who Perform Injury Prevention Training: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Serial Movement Assessment in Collegiate Athletes Who Perform Injury Prevention Training (NCT04748718), a na na study. The primary outcome is Landing Error Scoring System (LESS) Score.

2. Clinical Question

3. Trial Design

The registry describes a completed, single-group study sponsored by Northern Vermont University. The study began on 2021-08-17, and primary completion is recorded as 2022-03-29. Enrollment is listed as 62. The record classifies the phase and allocation as NA, masking as NONE, and the study model as SINGLE GROUP. Those entries are consistent with a longitudinal assessment without a randomized control-group comparison; they do not establish the details of recruitment or intervention delivery.

Participants were collegiate athletes performing an exercise-based neuromuscular injury prevention program. The primary outcome, Landing Error Scoring System (LESS) Score, was assessed at baseline (week 0), midseason (weeks 4-6), and end-of-season (weeks 10-12). The record describes assessment over 3 timepoints. It does not report whether every participant completed each assessment, how assessments were administered, or whether assessors were trained or blinded.

The study is framed as an evaluation of movement quality over an athletic season. Its stated hypothesis is that movement quality will improve over the season. Because there is no separate control group, observed change over time would not by itself distinguish the effects of training from other changes that occur during a season. Numerical outcome summaries and an analysis are not reported in the registry record. The record lists 2 outcome measures and 0 analyses; details of any analysis not posted in the registry record are not reported there.

The sample-size planning assumptions describe an illustration using a two-arm comparison, equal allocation, a two-sided significance level of 0.05, and a normal approximation. That framework is not the design described for this single-group study. Such planning calculations should not be read as the trial’s enrollment rationale or as observed power. The registry record does not report the study’s sample-size justification or a protocol-based statistical plan.

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 Landing Error Scoring System (LESS) Score, measured over assessing change over 3 timepoints: baseline (week 0), midseason (weeks 4-6), end-of-season (weeks 10-12).

The primary endpoint is the Landing Error Scoring System (LESS) Score, expressed in errors. The record describes it as the number of errors on a scale from 0-17 and states that a lower score indicates a better outcome. It is assessed at baseline (week 0), midseason (weeks 4-6), and end-of-season (weeks 10-12), so the intended endpoint captures movement quality at multiple points in the athletic season.

In general, a count of observed movement errors can provide a structured way to describe performance during a landing assessment. Repeated scores can be used to examine whether the recorded movement pattern changes over time. A score is an operational measure of movement quality, however, and is not itself a direct measure of injury occurrence. The registry record does not report how the assessment was conducted, how scores were assigned, or whether measurement reliability was assessed.

The record specifies a mean as the summary parameter and standard deviation as the measure of dispersion. These summaries would describe the average score and the spread of scores at an assessment, but no numerical means, standard deviations, or changes are reported in the registry record. Thus, the endpoint’s definition and direction are available, while the size and precision of any observed change are not.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

General statistical context helps clarify what the registry record can and cannot establish. The record describes a continuous outcome summarized by a mean and standard deviation, measured repeatedly in a single group. It does not report an analysis method or numerical outcome results. The explanations below describe general considerations for this type of design, not methods confirmed to have been used in this study.

What does a mean and standard deviation describe?

In general, the mean is a summary of the central or average value of a continuous measure. The standard deviation describes how spread out individual measurements are around that mean. For LESS, the record defines the measure as a number of errors, with lower scores indicating a better outcome. A mean can summarize the group’s scores at an assessment, while the standard deviation conveys how much scores vary among participants. Neither quantity alone describes the uncertainty in a change estimate. The record names these summary measures but does not report their numerical values.

Why does repeated measurement matter?

Each athlete may contribute scores at baseline (week 0), midseason (weeks 4-6), and end-of-season (weeks 10-12). In general, measurements from the same participant tend to be related, because they come from the same person. A statistical analysis of repeated measurements should account for this within-participant dependence rather than treating every score as unrelated. The choice of method may also depend on the number of assessments available for each participant and on the assumptions of the model. The registry record does not report the analysis method, covariance assumptions, or how incomplete repeated measurements were handled.

A change in a group mean over time and a participant-level change are not identical summaries. General methods can estimate average change while accounting for repeated observations, but the interpretation depends on the population included and the model used. If different participants contribute data at different timepoints, a comparison of means may also reflect changes in the composition of the observed group. The registry record does not report the number contributing LESS scores at each assessment or the analysis population.

What would an uncertainty interval add?

In general, a confidence interval expresses the uncertainty around an estimate under a specified statistical procedure and its assumptions. For a change in LESS, an interval would help readers assess the range of changes compatible with the observed data. A narrow interval indicates greater precision than a wide interval, all else being comparable. It does not resolve limitations of the design, such as the lack of a control group, and it does not establish causality. No confidence interval or change estimate is reported in the registry record, so the precision of the outcome cannot be assessed.

A p-value, when reported, describes how unusual data at least as inconsistent with a specified null hypothesis would be under the test’s assumptions. It is not the probability that the hypothesis is true, and it does not measure the size or practical importance of an effect. The registry record lists 0 analyses and does not report a p-value. No conclusion about statistical significance can be drawn from the stated hypothesis or the endpoint definition.

How should planning calculations be read?

The record describes a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The stated illustration considers detecting a stated fraction of the observed effect. In general, planning calculations depend on assumptions about the effect to detect, variability, design, and analysis. A planning sample size is not an observed result, and it is not observed power. The record does not report numerical planning outputs in the registry record described for this analysis.

The illustration’s two-arm assumptions do not match the registered single-group model. Its assumptions therefore should not be read as a description of how the study was designed or analyzed. The sample-size justification for the trial and its own statistical plan are not reported in the registry record. No calculation of a sample size or power can be inferred from enrollment alone.

Why can over-dispersion matter for counts?

General statistical context: a count outcome may show more variability than a model assumes. This is called over-dispersion. When present, an analysis that underestimates variability can give overly narrow uncertainty intervals and misleading test results. However, the LESS outcome is described as a score on a bounded scale, and the registry record does not state that a count model was used or that over-dispersion was assessed. It would therefore be inappropriate to attribute a particular model or correction to this study.

The scale’s range and direction are useful for interpreting a reported value, but they do not specify how scores should be modeled. A bounded outcome, repeated observations, possible missing scores, and the intended estimand are all considerations for a statistical plan. The registry record does not state how these issues were addressed. Without the analysis details and numerical results, the statistical interpretation must remain limited to the registered outcome definition and schedule.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists 2 outcome measures and 0 analyses. It does not provide the analysis details needed to determine how outcomes or comparisons were handled statistically. In general, testing multiple outcomes or multiple timepoint contrasts can raise a multiplicity question: the more statistical claims made, the greater the chance that at least one may appear notable by chance under the relevant assumptions. Methods for controlling or describing that issue depend on the prespecified questions and analysis plan. The record does not report a multiplicity strategy or identify a hierarchy of secondary outcomes.

The primary outcome is identified as LESS Score, with assessments at baseline (week 0), midseason (weeks 4-6), and end-of-season (weeks 10-12). The record does not report whether the primary comparison was change from baseline at each later assessment, a trend across all assessments, or another contrast. It also does not report whether any additional analyses were planned. No specific inferential claim can therefore be tied to a defined contrast.

Missing-data information is not reported in the registry record. There is no reported count of participants contributing primary outcome data at each timepoint, nor a description of reasons for missing assessments or methods for handling them. In general, missing measurements can affect both precision and interpretation, especially if the likelihood of a missing score is related to the score or to participant characteristics. The appropriate analysis depends on the missingness pattern and assumptions, which cannot be evaluated from the information reported.

The analysis population is not reported in the registry record. It is therefore unclear which participants would be included in any outcome summary or analysis. The enrollment count and adverse-event risk count do not establish the outcome analysis denominator.

11. 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 0% reporting threshold.

The adverse-event information lists the Injury Prevention Arm with 60 at risk. It records 0 serious adverse events, 0 other adverse events, and 0 deaths. No serious adverse event terms are listed. These figures describe the registry’s safety entries for that arm; they do not provide details about monitoring procedures, event definitions, or the period over which events were collected.

A zero count in a registry record should be read as no events reported in that entry, not as proof that an event could not occur or that every possible event was captured. The registry record does not explain whether the absence of listed events reflects active surveillance, passive reporting, or another collection process. It also does not give event-level details or clarify how the risk population was determined.

Enrollment is recorded as 62, whereas the adverse-event group lists 60 at risk. The registry record does not explain this difference. The safety denominator should not be assumed to be the denominator for LESS assessments, because the record does not report the outcome analysis population. The listed safety counts also do not answer the primary movement-quality question, which concerns LESS scores over the season.

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

The registry record establishes that a completed single-group study assessed movement quality in collegiate athletes performing an exercise-based injury prevention program. It identifies LESS Score as the primary outcome, defines lower scores as better, and specifies assessments at baseline (week 0), midseason (weeks 4-6), and end-of-season (weeks 10-12). The stated hypothesis is that movement quality will improve over the athletic season.

What the record does not establish is whether the scores improved, stayed similar, or worsened. Numerical outcome results, including means, standard deviations, changes, and uncertainty intervals, are not reported in the registry record. The 0 analyses entry also means that no analysis is posted in the record; it does not show that the study team did no analysis. The hypothesis must not be mistaken for a result.

Even if a change were reported, a single-group longitudinal study would describe a change over time without a separate control group to help distinguish training-related change from other influences. General influences could include other seasonal activities or familiarity with repeated testing; the registry record does not report whether these were assessed. The design therefore does not, by itself, identify a causal effect of the program.

LESS is a movement-quality score, not an injury outcome. The record’s description of injury-related conditions does not establish that this endpoint measures injuries or that injury events changed. The available safety entries list 0 serious adverse events, 0 other adverse events, and 0 deaths in the Injury Prevention Arm, with 60 at risk, but those entries do not fill the gap in the movement-quality results.

In general, a complete interpretation of a longitudinal result would consider the estimated change, its uncertainty, the participants contributing data at each assessment, and the analysis assumptions. Those details are not reported in the registry record. Accordingly, the defensible conclusion is about the registered research question and design, not about whether the program improved movement quality or changed injury risk.

13. Why This Trial Matters Statistically

This study’s statistical question is about change in a continuous movement-quality score across an athletic season. Repeated assessment can characterize whether a group’s scores vary over time, and the stated three-timepoint schedule makes the timing of assessment explicit. The outcome’s direction is also clear: lower LESS scores indicate a better outcome. These features help define what a future numerical result would need to address.

The design makes the distinction between describing change and estimating a treatment effect especially important. With a single group, a pattern over time has no concurrent control group against which to compare the athletes’ trajectory. Statistical modeling can account for repeated measurements and quantify uncertainty, but it cannot replace the missing comparison needed to separate program-related change from other changes over the season. This is a design limitation, not merely a choice of statistical test.

The registry record also illustrates why outcome definitions and outcome results are separate parts of a trial record. A defined scale, timeframe, and direction make the intended measurement interpretable, but they do not reveal the observed scores. Without numerical estimates and uncertainty, readers cannot assess the size, consistency, or precision of change. The absence of posted analysis details also prevents evaluation of the statistical approach.

Finally, the safety entries and the primary endpoint answer different questions. Counts of reported adverse events do not describe movement-quality change, and a movement score does not establish injury prevention. Keeping those questions distinct helps prevent a measure of performance during an assessment from being treated as evidence about subsequent injury occurrence. The record supports careful description of the study’s design and endpoints, while leaving its central outcome result unresolved.

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 principal trial-specific limitation is the absence of numerical LESS results in the registry record. Without scores, summary statistics, change estimates, or uncertainty intervals, the primary question cannot be answered from the posted results. Although the record names a primary endpoint and states a hypothesis, neither identifies the observed direction or size of change.

The single-group design has no separate control group. A change across baseline (week 0), midseason (weeks 4-6), and end-of-season (weeks 10-12) would be a change over time among assessed athletes, not a controlled estimate of the program’s effect. The record does not report whether other seasonal activities or exposure were considered.

Important operational details are not reported in the registry record, including eligibility criteria, participant characteristics, recruitment procedures, training dose, adherence, assessment procedures, and assessor reliability. The number contributing LESS data at each assessment, missing-data handling, analysis population, and statistical methods are also not reported. These omissions limit appraisal of measurement quality, completeness, and analytic choices.

The record lists 2 outcome measures but does not describe the other outcome information in the registry record used for this analysis, and it lists 0 analyses. It does not report a multiplicity plan, sample-size justification, or a protocol-based analysis plan. The planning assumptions described for a two-arm comparison do not match the single-group model and cannot stand in for those missing design details.

Finally, enrollment is 62 while the adverse-event risk count is 60, and the registry record does not explain the difference. The safety entries are not a substitute for outcome denominators or a full account of event ascertainment. These limitations constrain interpretation of both effectiveness-related questions and the completeness of reporting.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Serial Movement Assessment in Collegiate Athletes Who Perform Injury Prevention Training — NCT04748718.
• Registry record last updated 2024-04-01; status last verified 2024-03.
• Results first posted 2024-04-01.
• 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

NCT04748718 is a completed, single-group study sponsored by Northern Vermont University. It enrolled 62 and evaluated collegiate athletes performing an exercise-based neuromuscular injury prevention program. The study began on 2021-08-17, with primary completion on 2022-03-29. The registry lists phase and allocation as NA and masking as NONE.

The primary outcome is Landing Error Scoring System (LESS) Score, measured at baseline (week 0), midseason (weeks 4-6), and end-of-season (weeks 10-12). The score counts errors on a scale from 0-17, with lower scores indicating a better outcome. The stated hypothesis is that movement quality will improve over the season.

Numerical primary outcome results and analysis details are not reported in the registry record. The record lists 2 outcome measures and 0 analyses. Safety entries report 0 serious adverse events, 0 other adverse events, and 0 deaths among 60 at risk; the difference between this risk count and enrollment is not explained.