Effects of Task-Specific Step Training on Reactive Balance: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Effects of Task-Specific Step Training on Reactive Balance (NCT05734443), a non-randomized na study. The primary outcome is Trunk Angle at Touchdown of the First Recovery Step.

2. Clinical Question

The trial asks whether step training is associated with better reactive balance after tripping than no training, and how its results compare with treadmill training. Treadmill training is described in the registry record as a more commonly studied reactive-balance regimen that uses a specialized treadmill; step training is described as pragmatic and not requiring specialized equipment.

Participants completed step training, treadmill training, or no training, followed by a laboratory-induced trip to assess reactive balance. The primary measure was trunk angle at touchdown of the first recovery step, recorded one week after the three-week intervention. The endpoint description specifies an angle from vertical based on body-marker positions.

The registry record identifies a non-randomized, parallel-group design. Consequently, the group comparison is not equivalent to a randomized comparison: differences in participant characteristics or other factors could contribute to any observed group differences. The record does not report primary-outcome group means, variability, or an estimated comparison. It therefore does not establish from the posted results whether trunk angle differed among the groups.

3. Trial Design

This completed pilot trial is registered as NCT05734443 and is titled “Effects of Task-Specific Step Training on Reactive Balance.” The registry record lists a total enrollment of 30 and describes a parallel-group, non-randomized design with no masking. It lists step training, treadmill training, and control groups. The adverse-event record gives 10 participants at risk in each group. The record does not provide further detail about participant characteristics or eligibility.

Step training and treadmill training were each planned for two sessions per week over three consecutive weeks. Each session was described as lasting 0.5–1 hour, with 30 minutes of active training time per participant. Step training involved repeated volitional and reactive stepping movements that mimic movements needed for recovery. Treadmill training involved repeated exposure to simulated trips on a treadmill. The control group is described as receiving no training in the trial summary.

Participants experienced a laboratory-induced trip three weeks after the training period. The primary outcome was measured one week after the three-week intervention. The registry record lists five secondary outcomes: Recovery Step Length, Sacrum Height at Touchdown of the First Recovery Step, Gait Speed, Average Step Speed, and Trip Recovery Strategy. It reports seven outcome measures overall.

The trial is listed as completed, with a start date of 2022-11-01 and primary completion date of 2023-08-01. The sponsor is Virginia Polytechnic Institute and State University. The record does not report a statistical analysis plan, allocation procedure beyond the non-randomized designation, or the rationale for the enrollment target. It also does not report whether the outcome assessors were masked.

Because allocation was not randomized, the intervention groups may differ in ways that affect reactive balance, aside from the training itself. The record does not describe methods to address such differences. This design feature limits how directly any group contrast can be attributed to training, even if outcome estimates were available.

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.

6. Primary Endpoint

The registry lists the primary outcome as Trunk Angle at Touchdown of the First Recovery Step, measured over 1 week after the 3-week intervention.

The primary endpoint is trunk angle at touchdown of the first recovery step, measured in degrees. The registry defines it as the angle from vertical of a line connecting the midpoint of the greater trochanter markers and the midpoint of the acromion markers. The measurement is taken after a laboratory-induced trip, one week after the three-week intervention.

This endpoint captures a feature of body posture at a specific point in the recovery response: when the first recovery step touches down. In general, a measure tied to a defined event can make the timing of assessment more consistent than a measure taken at an unspecified point during movement. Trunk orientation offers a quantitative description of posture rather than a broad judgment of balance. The registry record does not report whether this measure has been validated for the trial population or how a change in its value should be interpreted clinically.

The endpoint is a continuous measure, and the registry identifies the planned summary as a mean with standard deviation. In general, a mean describes the central value of observations, while a standard deviation describes their spread around that mean. Neither summary alone shows how much individual participants overlap across groups. The registry record does not report the observed group means or standard deviations, an estimated group contrast, or its uncertainty. The direction and size of any observed difference therefore cannot be assessed from the posted results.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record identifies the primary measure as a continuous outcome summarized by a mean and standard deviation. It does not report the statistical analysis plan or any statistical analyses. The concepts below are general explanations of how such data are commonly interpreted; they are not descriptions of an analysis confirmed for this trial.

What does a mean describe?

In general, the mean is an average across participants’ measurements. For a continuous measure such as trunk angle, it provides a compact description of the group’s central value. The standard deviation describes how dispersed individual measurements are around that mean. A small standard deviation indicates less spread within the observed group, while a larger one indicates more spread. These summaries do not show the full distribution: unusual values, skewness, or clusters can be obscured by a mean and standard deviation.

The registry record names a mean and standard deviation as the outcome parameter and dispersion measure, but it does not report the actual values. It is therefore not possible to judge the observed spread, compare the group centers, or determine whether the data meet assumptions used by a particular model.

What would a group contrast mean?

In general, a group contrast expresses the estimated difference in an outcome between groups. A contrast is most informative when reported with uncertainty, such as a confidence interval. A confidence interval gives a range of values compatible with the data and the assumptions of the method. A narrow interval indicates greater precision than a wide interval. It does not, by itself, express the probability that a particular effect is true.

A p-value, in general, describes how unusual data at least as incompatible with a specified null hypothesis would be if that hypothesis and the model assumptions were correct. It is not a measure of effect size, clinical importance, or the probability that the null hypothesis is true. Because no contrast estimate, confidence interval, or p-value is reported in the registry record, these interpretations cannot be applied to trial results.

Why does allocation matter?

In general, randomization uses chance to assign participants and can reduce systematic differences between groups. In a non-randomized study, group membership may be related to participant characteristics or other factors that also affect the outcome. This creates the possibility of confounding: an observed group difference may reflect both the intervention and pre-existing differences. Statistical adjustment can sometimes address measured differences, but it cannot guarantee removal of unmeasured confounding. The registry record does not report adjustment methods or baseline group characteristics.

The parallel-group structure means the groups are assessed as separate intervention groups rather than as a planned sequence of treatments for each participant. In general, a comparison across such groups depends on how participants entered each group and on whether outcome measurements are available for comparable participants. Here, the record identifies the design as non-randomized and does not detail the allocation process.

How should precision be considered?

In general, precision reflects how much uncertainty surrounds an estimate. It depends on the amount and variability of outcome information, among other factors. A sample-size calculation is a planning exercise based on stated assumptions; it is not evidence that the observed effect is real or that the trial had a particular observed power. The registry record does not report the trial’s sample-size justification or its planned statistical power. It also does not report an effect estimate from which precision could be assessed.

A mean and standard deviation are descriptive summaries, while an inferential analysis attempts to estimate uncertainty in a contrast or test a specified hypothesis. Those are different tasks. Descriptive summaries alone do not establish whether a difference is statistically distinguishable from zero, nor whether an estimate is precise enough to be useful. No inferential results are reported in the registry record.

What assumptions might matter?

In general, methods for comparing means may rely on assumptions about independence of observations, the form of the outcome distribution, and the model used to describe variation. If observations are more variable than a model allows, uncertainty estimates can be too small; this is one reason over-dispersion matters in models designed for count data. The primary outcome in this trial is continuous, and the registry identifies a mean and standard deviation, but it does not name a model or report diagnostics. There is no basis in the registry record for saying which assumptions were checked or how any departures were handled.

Repeated training sessions do not by themselves mean that the outcome was analyzed as repeated measurements. The registry identifies a primary measurement after the intervention, but it does not report repeated outcome measurement, baseline outcome collection, or a longitudinal analysis. The statistical handling of any within-participant measurements is therefore not reported in the registry record.

What does the record establish?

The record establishes the intended endpoint, its unit, its measurement description, and its timeframe. It also identifies a non-randomized parallel design and lists secondary outcome names. It does not report results, analysis methods, missing-data procedures, or the population included in any analysis. Statistical interpretation must therefore remain focused on the design and measurement plan rather than on an unreported treatment-effect estimate.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Step Training", "Treadmill Training", "Control")
n   <- c(10, 10, 10)
m   <- c(27, 24.6, 28.4)
sp  <- c(8.2, 7.4, 6.9)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Step Training  10  27.000  8.200  21.134  32.866
CARM  Treadmill Training  10  24.600  7.400  19.306  29.894
CARM  Control  10  28.400  6.900  23.464  33.336

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists seven outcome measures overall and names five secondary outcomes in addition to identifying the primary outcome. It does not report how the outcomes were prioritized beyond the designation of a primary endpoint, or whether statistical testing was planned for each outcome. A multiplicity procedure, such as an adjustment for several simultaneous hypothesis tests, is not reported in the registry record.

In general, evaluating multiple outcomes can increase the chance of at least one apparently notable result occurring by chance when each is tested separately. The importance of this issue depends on the analysis plan, the relationship among outcomes, and the purpose of the comparisons. No testing strategy or multiplicity adjustment is reported, so it is not possible to assess how the trial’s outcome set was handled statistically.

The record does not report the number of participants with an observed primary outcome, the amount or pattern of missing data, or how missing measurements were treated. It also does not report whether any imputation, sensitivity analysis, or complete-case approach was used. These details affect interpretation because the analyzed participants may differ from those enrolled if measurements are missing.

The analysis population is not reported in the registry record. It is therefore unclear which participants, if any, were included in each outcome analysis and how deviations from the planned training schedule were handled. No statistical analyses are reported, so no analysis population can be inferred from posted estimates.

These are reporting gaps, not evidence that a particular method was or was not used outside the registry record. Without the statistical plan and outcome-level analysis details, the handling of multiple outcomes, missing measurements, and analysis populations remains unknown.

12. 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 registry record lists 10 participants at risk in each of the step training, treadmill training, and control groups. It reports zero serious adverse events, zero other adverse events, and zero deaths in each group. These figures describe the events recorded in the registry; they do not establish that no participant experienced an unlisted symptom or that the interventions carry no risk.

In general, zero observed events in a group do not imply that the underlying event risk is exactly zero. A small group can provide limited information about uncommon events, and uncertainty remains even when no event is recorded. These counts should therefore be read as a description of events reported during the trial, not as a precise estimate of safety or a comparison establishing equivalent risk between groups.

The registry record does not list serious adverse-event terms or provide further event narratives, severity details, timing, or an analysis of differences between groups. The posted safety information is consequently limited to the recorded counts and the number at risk in each group.

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

The registry record documents a pilot study designed to compare task-specific step training with treadmill training and no training on reactive balance after a laboratory-induced trip. It specifies trunk angle at touchdown of the first recovery step as the primary endpoint and describes when and how that measure was to be collected. It also lists other balance- and gait-related outcomes.

Those design details explain what the trial set out to assess, but they are not results. Group summaries and statistical comparisons for the primary endpoint are not reported in the registry record. As a result, the posted information does not show whether the groups had different trunk angles, how large any difference was, or how precisely it was estimated. No conclusion about the relative results of the training approaches can be drawn from the registry entry.

The non-randomized allocation is also important. In general, without random assignment, differences between groups may reflect participant characteristics or other influences as well as training. The registry record does not report baseline comparisons or an adjustment strategy that would help assess these possibilities. Even an observed association would therefore require careful interpretation before attributing it to the training regimen.

The record identifies the trial as a pilot and reports enrollment of 30. In general, pilot trials can help establish whether procedures and measurements can be implemented and can inform later research. Enrollment alone does not establish that a study can estimate an effect with a particular level of precision. The sample-size rationale is not reported in the registry record.

The recorded absence of adverse events is limited to the counts entered in the registry. It does not rule out uncommon events or establish that the interventions have the same safety profile. The registry record also does not report missing-data handling or which participants contributed to outcome analyses. Taken together, the entry provides a description of the intended comparison and its methods, but does not provide enough outcome information for an estimate of benefit, harm, or comparative effectiveness.

14. Why This Trial Matters Statistically

This trial addresses a statistical question that is easy to overlook: how to evaluate a movement-based intervention when the outcome is a continuous measurement taken during a specific recovery event. Defining trunk angle at the touchdown of the first recovery step ties the measurement to a precise point in the response to a laboratory-induced trip. The registry also defines the body landmarks used to construct the angle, making the intended measurement more explicit.

The comparison includes two active training approaches and a no-training control. In principle, this structure can distinguish changes associated with training from what is observed without training, while also allowing comparison between different training approaches. The registry’s non-randomized designation is central to interpreting any such contrast: group differences may be confounded, and the record does not describe methods to address that issue.

The pilot framing also raises questions about estimation and uncertainty. In general, pilot work can help assess feasibility and inform design decisions, but an effect estimate from a small study may be imprecise. The registry record does not report a sample-size justification or primary-outcome estimates, so readers cannot assess the precision or statistical performance of this trial from the posted entry.

The record illustrates the distinction between a detailed outcome definition and an outcome result. It documents the intended measure, timeframe, and broad training schedule, but does not report the group-level data needed to quantify differences. That distinction matters for clinical researchers: a registered question and endpoint do not substitute for an analysis with interpretable estimates and uncertainty.

15. 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 registry entry is that primary-outcome results are not reported. Group means, standard deviations, between-group estimates, and uncertainty measures are absent, preventing quantitative assessment of the study question. The registry record also reports no statistical analyses.

The non-randomized design limits causal interpretation. The record does not describe the allocation procedure in detail, report baseline group characteristics, or identify an adjustment strategy. If groups differed before training, those differences could influence the measured response to the laboratory-induced trip.

The trial is identified as a pilot with enrollment of 30, but the sample-size rationale and intended precision are not reported. The record does not provide participant eligibility criteria or further demographic information, limiting assessment of who the findings might represent even if outcome results were available.

Important analysis details are also absent: the number of participants with outcome measurements, missing-data methods, analysis populations, model specification, and handling of multiple outcomes are not reported in the registry record. The record does not describe measurement reliability, assessor masking, or whether baseline outcome values were collected. These omissions make it difficult to evaluate possible sources of bias or the robustness of any analysis.

Finally, the safety record is limited to event counts and participants at risk. It does not provide event descriptions or detailed safety analyses. These limitations concern the information reported in the registry record; they do not establish what may have been collected or analyzed outside it.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Effects of Task-Specific Step Training on Reactive Balance — NCT05734443.
• Registry record last updated 2025-09-24; status last verified 2023-09.
• Results first posted 2025-09-24.
• 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.

19. Record Summary

NCT05734443 is a completed, non-randomized, parallel-group pilot trial sponsored by Virginia Polytechnic Institute and State University. It enrolled 30 participants and compared step training, treadmill training, and a no-training control. The training schedule was two sessions per week over three consecutive weeks, followed by a laboratory-induced trip for assessment.

The primary outcome was trunk angle at touchdown of the first recovery step, measured one week after the three-week intervention. The registry lists five secondary outcomes and seven outcome measures overall. It reports zero serious adverse events, zero other adverse events, and zero deaths in each group, with 10 participants at risk per group.

Primary-outcome results, statistical analyses, the analysis plan, and missing-data methods are not reported in the registry record. The posted entry therefore describes the trial design and intended assessment but does not quantify differences between groups.