This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Effects of Two Supervised Training Programs for the Rehabilitation of Ankle Sprains (NCT01853462), a randomized na study. The primary outcome is Ankle Functional Stability, Via the Single-leg Hop for Distance Test.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01853462 |
| Phase | NA |
| Condition | Ankle Sprains |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Single |
| Enrollment | 22 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Lazaros Lazarou |
| Results posted | Yes |
2. Clinical Question
Population
The registry record concerns people with ankle sprains. It lists enrollment as 22, but eligibility details, participant characteristics, and the population's clinical setting are not reported in the registry record.
Intervention
One group received supervised proprioceptive neuromuscular facilitation (PNF) training. Details such as the exercises, session frequency, training duration, and adherence are not reported in the registry record.
Comparator
The other group received supervised balance training. The record does not report whether participants received any additional rehabilitation or other care alongside their assigned training.
Primary question
The trial aimed to assess ankle functional stability using the single-leg hop for distance test. The primary question is whether the recorded hopping distance differed over the assessment schedule between the PNF and balance training groups. The registry record does not report the group results or an analysis answering that question.
The stated purpose was to determine the effects of supervised balance and PNF training for rehabilitation of ankle sprains. The outcome description focuses on hopping forward using the sprained leg and maintaining the landing position. That makes the comparison about performance on a functional task, rather than a direct measure of pain or a specific joint motion. Pain, stability indices, range of motion, and ankle joint sense are among the listed secondary outcomes, but their results are not reported in the registry record.
3. Trial Design
The registry describes a randomized, single-masked, parallel-group trial. Participants were assigned to supervised PNF training or supervised balance training. The masking description does not identify who was masked, so it is not possible to tell from the registry record whether participants, assessors, or other study personnel were masked. The method used to generate the random allocation sequence and whether allocation was concealed are not reported in the registry record.
Enrollment is listed as 22. The adverse-event fields list 11 participants at risk in each group for other adverse events. These entries do not establish how many participants completed training or each assessment; completion, withdrawal, and missing-measurement details are not reported in the registry record. The listed study status is completed. The study start is recorded as 2014-12, and primary completion as 2015-11. Phase is listed as NA.
The primary endpoint was measured at baseline, after completion of training (follow-up 1), and eight weeks after completion of training (follow-up 2). The record does not describe the training schedule, assessment procedures beyond the endpoint description, or the exact timing of baseline relative to randomization and training.
The registry lists 31 outcome measures, including the primary hop-distance measure and secondary outcomes covering stability, dorsiflexion range of motion, pain, and joint sense. It lists no analyses. The analysis population, statistical model, handling of repeated measurements, and any adjustment for baseline values are not reported in the registry record. Consequently, the design can be described from the allocation and measurement schedule, but the analysis strategy and its execution cannot be reconstructed.
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
| Stage | Proprioceptive Neuromuscular Facilitation (PNF) | Balance |
|---|---|---|
| STARTED | 11 | 11 |
| COMPLETED | 10 | 10 |
| NOT COMPLETED | 1 | 1 |
Reasons for not completing this period:
| Reason | Proprioceptive Neuromuscular Facilitation (PNF) | Balance |
|---|---|---|
| Withdrawal by Subject | 1 | 1 |
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.
| Characteristic | Unit | Proprioceptive Neuromuscular Facilitation (PNF) | Balance | Total |
|---|---|---|---|---|
| Participants analysed | 10 | 10 | 20 | |
| Age, Continuous | years | 21.8 (SD 3.8) | 21.5 (SD 1.8) | 21.7 (SD 2.9) |
| Sex: Female, Male: Female | Participants | 7 | 7 | 14 |
| Sex: Female, Male: Male | Participants | 3 | 3 | 6 |
6. Primary Endpoint
The registry lists the primary outcome as Ankle Functional Stability, Via the Single-leg Hop for Distance Test, measured over Baseline, after the completion of training (follow-up 1), and eight weeks after the completion of training (follow-up 2).
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | Centimeters |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is ankle functional stability measured with the single-leg hop for distance test. Participants used the sprained leg to hop forward as far as possible and held the landing position for 2sec. They performed three trials, and the mean hopping distance was used for analysis. The unit is centimeters; the registered summary measure is the mean, with standard deviation as the dispersion measure.
The test captures performance on a task that requires forward propulsion and a controlled landing on the affected leg. It therefore offers a functional performance measure rather than a direct measurement of pain, range of motion, or a particular stability index. The registry record does not report the test's reliability, its threshold for a clinically important change, or how the endpoint was selected in relation to the secondary outcomes.
Assessment was planned at baseline and at follow-up 1 and follow-up 2. Repeated observations can describe both the endpoint at a given assessment and its pattern over time. However, the record does not report endpoint values, variability estimates, or between-group comparisons at any assessment. The endpoint description alone therefore explains what was measured, but not what the trial found.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies the clinical comparison and the primary measurement, but it does not report the primary outcome results. It gives no mean hopping distances, standard deviations, between-group estimates, confidence intervals, or p-values. It also lists no analyses. There is consequently no posted estimate of the difference between the supervised PNF and balance training groups to interpret, and no basis in the registry record for describing the direction or precision of a treatment contrast.
The primary endpoint was scheduled at baseline, follow-up 1, and follow-up 2. Those repeated measurements could be used to examine group patterns at each assessment or changes over time, depending on the chosen analysis. The registry record does not state which comparison was designated as the main inferential contrast, how baseline measurements would enter the analysis, or whether a group-by-time model was planned. It is therefore not possible to determine whether an analysis should be read as a comparison at a single follow-up, a comparison of change, or a joint assessment across follow-ups.
The enrollment entry is 22, and adverse-event fields list 11 participants at risk in each group. These details describe the registry record, but they do not supply outcome data or establish how many observations were available for analysis. Information about attrition, missing measurements, and analysis populations is not reported in the registry record. Precision cannot be judged without the observed endpoint values and their variability.
The registry lists secondary outcomes that include anterior-posterior, medial-lateral, and overall stability indices; ankle dorsiflexion range of motion; several pain measures; and ankle joint sense for 10° dorsiflexion. Their presence indicates a broader set of measurements, but no results for them are reported in the registry record. It would be inappropriate to infer that any outcome favored one group or that findings were consistent across outcomes.
The record's adverse-event fields list no affected participants for serious or other adverse events in either group, and no deaths. These are registry entries, not a substitute for a detailed safety analysis; definitions, collection procedures, and follow-up completeness are not reported in the registry record. Overall, the available record permits a description of the intended comparison and endpoint, but not an estimate of benefit, harm, or statistical uncertainty.
9. Statistical Methods Explained
What does a mean represent?
The registered primary summary is the mean hopping distance. In general, a mean is a measure of the center of a set of observations: individual distances contribute to a group average. A mean can be useful for describing a continuous measure such as distance, but it does not show how similar or different participants' measurements are. The registry also specifies standard deviation as the dispersion measure. In general, standard deviation describes the spread of observations around their mean. Neither group means nor standard deviations are reported in the registry record, so the size and variability of the observed distances cannot be assessed.
How would a group comparison be interpreted?
In general, an unadjusted comparison of group means describes the difference between the observed averages without accounting for other variables. An adjusted comparison can account for measured features or baseline values, depending on the model. Those approaches answer related but not identical questions. The registry record lists no analyses and does not report a model, a contrast, or an adjusted estimate. It is therefore not possible to say which approach was used or whether any recalculated comparison would match the sponsor's analysis. No sponsor analysis is reported in the registry record.
A confidence interval, in general, expresses the uncertainty around an estimate under the assumptions of the analysis. A narrow interval indicates greater precision than a wide interval, while an interval compatible with effects in different directions may leave the direction uncertain. The registry record does not report a confidence interval for the primary endpoint. A p-value, in general, describes how compatible the observed data are with a specified null model under the test's assumptions; it does not measure the size or clinical importance of an effect. No primary p-value or test is reported in the registry record. Neither type of statistic can be reconstructed from the endpoint description alone.
Why do repeated assessments matter?
The endpoint is scheduled at baseline, follow-up 1, and follow-up 2. Repeated measurements from the same participant are generally related, rather than independent observations. An analysis that treats them as independent can misrepresent uncertainty. A repeated-measures model can account for within-participant correlation, but its suitability and details depend on the data and assumptions. The record does not report whether such a model was planned or used, how measurements at the different assessments were compared, or how missing follow-up observations were handled.
Baseline measurements can help describe the groups before training and may be included in an analysis to improve the comparison. In general, a baseline-adjusted follow-up comparison and a comparison of changes from baseline use different statistical formulations. The registry record does not identify a primary follow-up contrast or state whether baseline adjustment or change scores were used. Without results and a specified model, no estimate of change or between-group difference can be interpreted.
What is the role of variability and distribution?
Standard deviation is a familiar summary when a continuous measure is reasonably represented by a mean and spread. In general, marked skew, outliers, or a distribution with unusual features can affect how well a mean-based model describes the data. Residual diagnostics and plots can help assess model fit, and robust methods may be considered when assumptions are not adequate. These are general considerations, not methods documented for this trial. The registry record does not report distributions, diagnostics, transformations, or any alternative analysis.
Over-dispersion is most directly relevant to count outcomes, where observed variability exceeds what a chosen count model assumes. The primary endpoint is continuous hopping distance, not a count, so over-dispersion is not the central issue for interpreting that endpoint. More generally, a method should match the outcome type and the way observations are collected. The record does not identify statistical methods for the listed secondary outcomes either.
What do the planning assumptions mean?
The sample-size planning description characterizes its figures as illustrations based on a stated fraction of the observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. It specifies participants per arm for outcomes other than time-to-event outcomes. Such calculations are planning illustrations: they describe the sample size that a hypothetical future study might require under stated assumptions. They are not observed power, evidence that the trial was adequately powered, or a substitute for the actual effect estimate and its uncertainty. The registry record does not report the numerical planning outputs or a sample-size justification from the trial's own design.
For a planning calculation to be informative, its assumed effect and variability must be credible for the intended future study. If the observed effect is uncertain, planning around it can produce unstable estimates of required sample size. This general limitation does not establish that any particular planning assumption was unsuitable. The registry record does not report the numerical observed effect, the detailed calculation inputs, or a trial-specific design justification.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 31 outcome measures, including a primary endpoint and secondary measures of stability, motion, pain, and joint sense. Assessing many outcomes can raise a multiplicity issue: in general, the chance of at least one apparently notable result can increase when many statistical comparisons are made. A prespecified hierarchy, a limited set of primary contrasts, or an adjustment procedure can help clarify interpretation. The registry record does not report a multiplicity strategy, and it lists no analyses. It is not possible to tell whether adjustments were planned or whether some outcomes were considered exploratory.
The primary endpoint has measurements at baseline, follow-up 1, and follow-up 2. Considering several assessments can add further choices about which contrast to emphasize. The record does not report whether the primary inference concerned a particular follow-up, an overall time pattern, or change from baseline. This makes it especially important not to select or imply a favorable comparison without a stated analysis plan and posted results.
Missing-data handling is also not reported in the registry record. The record does not provide participant flow, reasons for missing measurements, completion by group, or an analysis population. General methods for missing data rely on assumptions about why observations are unavailable; those assumptions cannot be evaluated from group enrollment entries alone. The listed adverse-event denominators do not establish the number of endpoint observations available.
Finally, the record does not report whether analyses followed intention-to-treat principles, used a per-protocol population, or applied another population definition. These omissions prevent a full assessment of analysis choices, but they do not show that a particular procedure was or was not used outside the registry record.
11. What the Result Does, and Does Not, Mean
The record supports a clear description of the intended comparison: supervised PNF training versus supervised balance training for rehabilitation of ankle sprains, with hopping distance as the primary functional outcome. It also identifies the measurement schedule and the summary measure. These details help readers understand what the trial set out to assess.
The record does not support a conclusion about which training group had greater hopping distance, whether the groups differed, or how precisely any difference was estimated. There are no reported primary outcome values or analyses. The absence of a reported result is not evidence that the groups were equivalent, nor is it evidence that one training approach was superior. Those interpretations require estimates and uncertainty from an analysis.
The same caution applies to secondary outcomes and adverse events. The registry lists several additional outcome measures but does not report their results. Its adverse-event fields record no affected participants for serious or other events and no deaths, but definitions, ascertainment, and completeness of reporting are not described. These entries alone cannot establish comparative safety.
General statistical interpretation distinguishes the estimated size of a difference from its precision and from its clinical importance. A statistically uncertain estimate may still be compatible with a range of effects; a precise estimate does not by itself establish whether an effect matters to patients. The registry record does not provide the estimates or clinical-importance threshold needed for those judgments. Accordingly, its most defensible contribution is the description of the study question and design, not a claim about treatment effects.
12. Why This Trial Matters Statistically
Statistically, the trial illustrates the importance of separating a well-defined measurement from a reported result. The registry names a continuous functional endpoint, describes how hopping distance was collected, and specifies the mean and standard deviation as summaries. Those details identify the kind of data and the intended measurement, but they do not supply an estimate or its uncertainty.
The repeated assessment schedule also makes the analysis question important. Baseline, follow-up 1, and follow-up 2 measurements can support different contrasts, and observations from the same participant are generally correlated. Without a reported model or primary contrast, readers cannot determine how time and baseline values entered the analysis or what inferential question an estimate would answer.
The registry's listing of 31 outcome measures highlights another common issue: multiple outcomes can broaden a trial's descriptive scope while making the inferential plan more consequential. Transparent reporting of outcome hierarchy, analysis populations, missing-data procedures, and multiplicity handling helps readers distinguish prespecified evidence from exploratory findings. Those details are not reported in the registry record.
The record therefore serves as a reminder that registration information and outcome reporting have different roles. The design and endpoint descriptions clarify what was intended; posted estimates, uncertainty intervals, and a transparent analysis are needed to evaluate the findings. With no analyses listed, the statistical interpretation remains limited to the planned comparison and the information explicitly recorded about the study.
13. 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 main limitation for interpreting this trial is that the registry record does not report the primary outcome values or any analyses. Without group means, standard deviations, an effect estimate, or uncertainty intervals, the magnitude and precision of the primary comparison cannot be assessed. The record also does not report results for the listed secondary outcomes.
Important design and analysis details are absent from the registry record. These include participant eligibility and baseline characteristics, the randomization procedure, who was masked, training content and adherence, participant flow, missing measurements, analysis populations, and the statistical model. The record does not identify a primary follow-up contrast or describe how repeated measurements and multiple outcomes were handled. These are reporting gaps; they do not establish what the investigators did outside the registry record.
Enrollment is listed as 22, and the adverse-event fields list 11 participants at risk in each group. These entries do not show endpoint completion or the number included in any analysis. The sample-size planning description is an illustration based on the observed effect, but its numerical outputs and detailed inputs are not reported in the registry record. It should not be treated as a trial-specific design justification or evidence of observed power.
The endpoint description explains the hopping task but does not report its measurement properties or a threshold for clinically important change. Thus, even if a numerical difference were available, the registry information alone would not establish its practical importance. The study status is listed as completed, but completion status does not fill the gap in posted outcome results.
14. Related Tutorials
15. Related Statistical Calculators
16. Sources
- ClinicalTrials.gov: Effects of Two Supervised Training Programs for the Rehabilitation of Ankle Sprains — NCT01853462.
- Registry record last updated 2018-11-01; status last verified 2018-03.
- Results first posted 2018-11-01.
- 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.
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17. Record Summary
The registry record describes NCT01853462, titled “Effects of Two Supervised Training Programs for the Rehabilitation of Ankle Sprains.” It lists a randomized, single-masked, parallel design comparing supervised PNF training with supervised balance training. Enrollment is 22, status is completed, and phase is listed as NA. The recorded study start is 2014-12, with primary completion in 2015-11.
The primary outcome is ankle functional stability measured by single-leg hop distance, summarized as a mean with standard deviation at baseline, follow-up 1, and follow-up 2. The registry lists 31 outcome measures and 0 analyses. It does not report primary or secondary outcome results, analysis details, or missing-data procedures. The adverse-event fields list no affected participants for serious or other adverse events and no deaths in either group.