Validation of Plantar Orthoses for Abnormal Plantar Arch Using a New Non-invasive Clinical Imaging System: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Validation of Plantar Orthoses for Abnormal Plantar Arch Using a New Non-invasive Clinical Imaging System (NCT05163418), a non-randomized na study. The primary outcome is Change From Baseline in Body's Postural Symmetry Index(SSIM Gray) at 2 Months.

2. Clinical Question

The study therefore addresses both measurement and intervention questions: whether the imaging system can detect changes in posture, and how postural symmetry scores change after orthosis use in the two foot-arch groups. The registry summary states an intended system accuracy of 95% and an expectation that orthoses should improve the postural symmetry index. Those statements describe the project’s aims; they are not evidence that either goal was achieved. The primary endpoint is a change score over the intervention period, not a direct comparison of the two orthosis groups with a randomized control. Since the control group attended only at baseline, it cannot provide a corresponding change score. The record does not report an estimated treatment effect, uncertainty interval, or statistical test for the primary question.

3. Trial Design

This was a completed, parallel-group study with non-randomized allocation and no masking. The registry lists a total enrollment of 65 and identifies three groups: flat feet, high arches feet, and normal arches feet as a control group. The study dates recorded are a start on 2021-10-08 and primary completion on 2024-02-02. The phase is listed as not applicable.

Participants in the flat-feet group were described as having flat feet according to foot posture index, validated by clinical assessment; the high-arches group was described in a corresponding way. The control group consisted of people with normal arches. The interventions were devices: foot orthosis for flat feet and foot orthoses for high arches feet. The registry does not give further details about the devices, how they were fitted, how long or how often they were used, or other aspects of intervention delivery.

Because allocation was not randomized, the groups may differ in ways other than the intervention. The record does not describe a matching procedure or adjustment strategy. It also states that the normal-arches control group completed the baseline visit only. That group therefore cannot support a comparison of changes over time with the orthosis groups. These design features limit what can be inferred from differences between groups, even if numerical outcome results were available.

The registry lists six outcome measures and zero statistical analyses. Numerical primary outcome results and a detailed statistical plan are not reported in the registry record. Details such as eligibility criteria, participant flow, reasons for withdrawal, and analysis populations are also not reported in the registry record. The trial’s completion status indicates that the study is recorded as completed, but completion alone does not establish that all planned measurements were collected or analyzed.

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

Analysis population for the primary outcome, as defined in the registry: The normal arches control group only completed the baseline visit, therefore change from baseline outcome measures are not reported.

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 Change From Baseline in Body's Postural Symmetry Index(SSIM Gray) at 2 Months, measured over Baseline and 2 months.

The primary endpoint is change from baseline in the body’s postural symmetry index, SSIM Gray, at 2 months. It is recorded as a continuous measure, with a mean and standard deviation specified as the summary form. The measurement is calculated from a full-body image acquired with the Cryovision topographic color imaging system. The registry describes the scale as ranging from -1 to 1: 0 indicates no symmetry, 1 indicates perfect symmetry, and -1 indicates perfect anti-symmetry.

A change score expresses how a participant’s measured value differs from their baseline value over the stated follow-up period. In general, such an endpoint is used to characterize change during an intervention period; its interpretation depends on the measurement’s meaning, the quality and consistency of image acquisition, and the analysis used. Those are general considerations, not additional findings about this study.

The endpoint is relevant to the project’s stated aim of assessing postural symmetry and evaluating the imaging system. However, the record does not report the group means, standard deviations, change estimates, or uncertainty around those estimates. It also says the normal-arches control group completed baseline only, so change-from-baseline outcomes are not reported for that group. The scale description explains how to interpret values, but without observed results it does not establish the direction or size of any change in either orthosis group.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the primary measure as continuous and specifies a mean and standard deviation. In general, a mean describes the central value of observations, while a standard deviation describes their spread around that mean. For a change-from-baseline endpoint, the relevant value is the difference between a follow-up measurement and baseline for an individual, summarized across participants. The registry gives the endpoint timeframe as baseline and 2 months but does not report the resulting group summaries.

What does a change score represent?

Generally, a change score puts each participant’s follow-up measurement in relation to that participant’s starting measurement. It can describe the observed trajectory during the study period, but it does not by itself establish that the intervention caused the change. In a non-randomized study, other differences between groups or changes over time may also be relevant. For this trial, the normal-arches control group completed baseline only, so no control-group change score is reported.

How should uncertainty be considered?

In general, a point estimate is more informative when accompanied by a measure of uncertainty, such as a confidence interval. The interval helps readers judge the range of effects that remain compatible with the data and analysis. A p-value addresses a different question about data compatibility under a statistical model and null hypothesis; it does not measure the size or clinical importance of an effect. The registry record does not report primary outcome estimates, confidence intervals, or p-values, so none of these interpretations can be made for the primary endpoint.

What do the design choices imply?

Allocation was non-randomized and masking was absent. As a general principle, random allocation can help balance measured and unmeasured participant characteristics between intervention groups, while masking can reduce some forms of knowledge-related influence on measurement or assessment. Neither feature is present according to the registry. The record does not explain the allocation procedure or whether image assessment was performed independently of group information. These details are not reported in the registry record and should not be presumed.

The parallel-group structure means groups are followed as separate sets of participants rather than as a crossover sequence. The group definitions are based on foot-arch status, and the treatments differ by that status. The normal-arches group is a control group, but because it attended only at baseline it does not serve as a follow-up comparator for the primary change endpoint. Any comparisons between the two orthosis groups would also need to account for their distinct baseline conditions; no such analysis is reported.

What does the planning illustration mean?

The registry describes planning illustrations based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The effect to detect is described as a stated fraction of the observed effect. For continuous outcomes, the planning quantities are expressed as participants per arm. The numerical planning values are not reported in the registry record.

In general, a sample-size calculation estimates how many participants may be needed under specified assumptions to detect a chosen effect with a selected probability of statistical significance. Such a calculation is a planning exercise, not a description of the study’s achieved precision. When an illustration uses an observed effect, it depends on that effect estimate and the stated assumptions; it does not establish that the original study had a particular probability of detecting the effect. These illustrations are not observed power. The registry does not report the original design’s sample-size justification or enough numerical information to assess the planning illustrations independently.

Why can variability matter?

As a general statistical concept, variability affects precision: greater spread in measurements can make a mean or change estimate less precise for a given amount of information. Continuous imaging-derived scores may vary across participants, and the recorded standard deviation would help describe that variability. The record specifies standard deviation as the intended dispersion measure but does not give observed values. It also does not report whether data distributions, outliers, or measurement reliability were assessed.

For count outcomes, over-dispersion is a general concern when observed variability exceeds what a simple count model assumes. That issue is not the stated form of the primary endpoint, which is continuous. The registry does not report a model for the primary outcome or for the adverse-event counts. Therefore, no claim about a particular distribution, model fit, adjustment, or over-dispersion assessment can be made.

Finally, the registry lists six outcome measures and zero statistical analyses. It does not report a prespecified hierarchy among outcomes, covariate adjustments, handling of multiple comparisons, missing-data methods, or analysis populations. Those methods are not reported in the registry record. Their absence from the record means readers cannot determine whether the numerical analyses, if conducted elsewhere, followed a prespecified strategy.

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("Experimental: Flat Feet", "Experimental: High Arches Feet")
n   <- c(22, 7)
m   <- c(-0.031, 0.01)
sp  <- c(0.054, 0.061)
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  Experimental: Flat Feet  22  -0.031  0.054  -0.055  -0.007
CARM  Experimental: High Arches Feet  7  0.010  0.061  -0.046  0.066

11. Multiplicity, Missing Data and Analysis Populations

The registry lists six outcome measures and zero statistical analyses. It does not identify a hierarchy among the outcomes, state which additional outcomes were confirmatory or exploratory, or report a strategy for controlling multiplicity. In general, examining multiple outcomes can increase the chance of finding an apparently notable result by chance if each is tested separately. A prespecified approach can help readers understand how that concern was handled. Such an approach is not reported in the registry record, so the scope of any multiplicity adjustment cannot be assessed.

Information about missing outcome data is limited. The registry explicitly states that the normal-arches control group completed the baseline visit only and that change-from-baseline outcomes are not reported for that group. It does not report the number of participants with paired baseline and 2-month measurements in either orthosis group, reasons for missing follow-up, or methods for handling missing values. Whether participants were excluded from any outcome analysis is not reported in the registry record.

The record also does not define analysis populations, such as whether all enrolled participants or only participants with available measurements were included. It does not report a plan for protocol deviations, withdrawals, or incomplete images. These details matter because the set of participants analyzed can affect the meaning of a group estimate. Enrollment of 65 does not indicate the number included in each endpoint analysis.

These gaps prevent assessment of whether outcome selection, missing follow-up, or analysis population decisions could have influenced the reported findings. Since numerical primary results and analysis details are not reported in the registry record, no correction for multiplicity or missingness can be evaluated.

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.

Most frequent non-serious adverse event terms

The registry reports serious adverse events for the flat-feet group as 0 among 34 at risk, for the high-arches group as 0 among 11 at risk, and for the normal-arches control group as 0 among 20 at risk. Deaths are listed as 0 in each group. These are the counts recorded in the registry, not evidence that no unrecorded events occurred.

For other adverse events, the record lists 4 among 34 at risk in the flat-feet group, 4 among 11 at risk in the high-arches group, and 0 among 20 at risk in the control group. The registry does not provide event descriptions in the listed serious-event terms, nor does it report further detail about timing, duration, severity, or whether an event was judged related to an intervention. Those details are not reported in the registry record.

These counts should be read as descriptive safety information. The study was non-randomized, and the groups differed in their foot-arch categories and size. The record does not give a statistical comparison of adverse events. The counts alone do not establish comparative risk, causation, or the completeness of safety surveillance.

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

The registry record documents a completed study intended to evaluate plantar orthoses and a non-invasive imaging system in people with flat or high arches. It defines a primary endpoint based on change in an image-derived postural symmetry score from baseline to 2 months. It also records the scale’s interpretation and lists adverse-event counts. These details clarify what the investigators set out to measure and what safety counts were entered in the registry.

However, the numerical primary outcome results are not reported in the registry record. The stated goal that Cryovizion should detect posture changes with an accuracy of 95%, and the expectation that orthoses should improve postural symmetry, are aims described in the study summary. They cannot be treated as observed results. Without group estimates and uncertainty measures, the record does not show the direction, size, or precision of postural symmetry changes.

The findings should also not be interpreted as a randomized comparison. Allocation was non-randomized, and the normal-arches control group completed baseline only. That group therefore has no reported change-from-baseline result for comparison. The record does not report adjustments for baseline differences or other characteristics. These limitations matter even before considering the lack of numerical outcome findings.

More generally, an observed change in a continuous measure is not by itself proof that an intervention caused that change. Interpretation requires the outcome estimates, their uncertainty, the measurement context, and an appropriate account of the study design. Those elements are not available in the registry record for the primary endpoint. The available safety counts likewise do not establish whether events were caused by an intervention or whether the groups had comparable event ascertainment.

The defensible conclusion is therefore narrow: the record describes the study design, endpoint, stated aims, and recorded safety counts, but does not provide enough primary outcome information to assess the effect or performance of the imaging system. This is a statement about what the registry record reports, not a conclusion about results that may exist outside it.

14. Why This Trial Matters Statistically

This trial is statistically interesting because it combines an intervention question with a measurement question. The project aimed to assess plantar orthoses and to evaluate whether a non-invasive imaging system could detect postural change. These questions are related but distinct. An imaging system’s ability to measure change is not the same as evidence that an intervention changes the measured outcome. Keeping measurement performance separate from intervention effects is important when interpreting a study’s aims and results.

The endpoint is a continuous, image-derived score with a defined scale from -1 to 1. Continuous measures can describe the magnitude and direction of change, but useful interpretation depends on transparent estimates and uncertainty. The registry specifies a mean and standard deviation but does not report those outcome summaries. This means readers cannot assess the observed variation, precision, or practical interpretation of the score from the registry record.

The design also highlights the importance of a suitable comparator. Non-randomized allocation can leave differences between groups that influence outcomes, and the normal-arches group completed baseline only. A baseline-only group cannot show how its score changed over the same follow-up period. This makes the distinction between a control label and a usable follow-up comparison especially important.

Finally, the record shows how registry entries can convey useful methods and safety information while leaving key analytical details unavailable. It lists six outcome measures and zero statistical analyses, and does not report primary outcome estimates or missing-data methods. That absence constrains interpretation and makes clear why study aims, endpoint definitions, and numerical findings must be considered separately. The study matters statistically as a case in which measurement validity, group comparability, follow-up, and transparent reporting all shape what conclusions can be drawn.

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.

Several trial-specific limitations affect interpretation. First, the study was non-randomized, so the intervention groups may differ for reasons related to their foot-arch status or other characteristics. The registry does not report an adjustment strategy, matching procedure, or detailed allocation process. Group comparisons would therefore require caution even if numerical outcome estimates were available.

Second, the normal-arches control group completed only the baseline visit. It cannot provide a 2-month change score, so it is not a like-for-like follow-up comparator for the primary endpoint. This leaves the primary change question focused on the two orthosis groups, with no reported control-group change for context.

Third, the registry does not report the primary outcome’s numerical results, group-specific sample sizes for analysis, or measures of precision. It also does not describe image acquisition consistency, assessor masking, measurement reliability, or how unusable images were handled. Those details are not reported in the registry record, so the performance of the imaging measure cannot be evaluated from the entry.

The record lists six outcome measures but zero statistical analyses. Prespecification, multiplicity handling, missing-data methods, and analysis populations are not reported in the registry record. Enrollment of 65 does not establish how many participants completed follow-up or contributed to the primary endpoint.

Finally, the safety information is limited to event counts. Descriptions, timing, severity details, attribution, and ascertainment procedures are not reported in the registry record. Together, these limitations restrict assessment of both the intervention findings and the imaging system’s intended role.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Validation of Plantar Orthoses for Abnormal Plantar Arch Using a New Non-invasive Clinical Imaging System — NCT05163418.
• Registry record last updated 2025-07-30; status last verified 2025-07.
• Results first posted 2025-07-30.
• 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

NCT05163418 is recorded as a completed, non-randomized, parallel-group study with no masking and phase listed as not applicable. Enrollment is 65. The study began on 2021-10-08 and reached primary completion on 2024-02-02. It concerns flat feet, high-arched feet, plantar orthoses, and a non-invasive imaging system.

The primary endpoint is change from baseline in SSIM Gray at 2 months, based on full-body images from the Cryovision system. Numerical primary outcome results are not reported in the registry record. The normal-arches control group completed baseline only, and change-from-baseline outcomes are not reported for that group. The record lists six outcome measures and zero statistical analyses.

Serious adverse-event counts are 0 in each group; other adverse-event counts are 4 in the flat-feet group, 4 in the high-arches group, and 0 in the control group. The registry does not report enough outcome or analysis detail to assess the primary effect or its precision.