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 The Effect of Diathermy Therapy on Isolated Lumbar Extension (ILEX) Training (NCT06852872), a randomized na study. The primary outcome is Maximal Isometric Force of the Back Extensors.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT06852872 |
| Phase | NA |
| Condition | Resistance Training, Healthy Participants Study |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 26 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Applied Sciences and Arts of Southern Switzerland |
| Results posted | Yes |
2. Clinical Question
The study asks whether adding Capacitive Resistive Electric Transfer (CRET) therapy to Isolated Lumbar Extension (ILEX) training changes maximal isometric force of the back extensors, compared with sham CRET therapy alongside ILEX training. Its summary also describes an interest in preheating before resistance training. The primary measure is the force recorded during a maximal voluntary isometric contraction on the ILEX machine.
Population
Healthy participants, including males and females, with no prior experience with ILEX training, are described in the summary. The record’s enrollment figure is 26, while its summary describes a cohort of 14. How those figures relate is not reported in the registry record.
Intervention
The intervention group receives CRET therapy and ILEX training. The summary describes a 9-week training program with a total of 18 sessions. The specific delivery schedule for CRET therapy is not reported in the registry record.
Comparator
The sham group receives sham CRET therapy and ILEX training. This comparison is intended to separate the effect associated with active CRET therapy from changes occurring during ILEX training and the study period.
Primary question
How does maximal isometric force of the back extensors change over the stated assessment time points in the intervention group compared with the sham group? Numerical outcome results and a reported between-group effect are not reported in the registry record.
The primary outcome timeframe is listed as baseline, 3 weeks, and 6 weeks, while the summary describes follow-up measurements after the ninth and eighteenth sessions. These descriptions do not align exactly, and the record does not explain the difference. The study is marked completed, but completion status alone does not establish that results have been reported.
3. Trial Design
The registry describes a randomized, double-masked, parallel-group study. Participants are allocated to an intervention group receiving CRET therapy and ILEX training or a sham group receiving sham CRET therapy and ILEX training. The record does not say which people were masked, how randomization was generated or concealed, or whether masking was maintained.
The listed enrollment is 26. Separately, the brief summary describes recruiting a cohort of 14 healthy individuals with no prior ILEX training experience. The record does not clarify whether one figure refers to planned recruitment and the other to actual enrollment, or otherwise reconcile them. The study is marked completed. Its phase is listed as not applicable.
The summary describes a 9-week program consisting of a total of 18 training sessions. Baseline measurements were planned in the week before training began. It describes follow-up measurements after the ninth and eighteenth sessions, and says the final measurement would take place after a minimum break of 48 hours following the last training session. The primary-outcome timeframe, however, is listed as baseline, 3 weeks, and 6 weeks. How these time descriptions correspond is not reported in the registry record.
The primary outcome is maximal isometric force of the back extensors. The record also lists secondary outcomes concerning endurance, erector spine muscle thickness, lumbar flexibility and range of motion, perceived effort, discomfort, thermal sensation, and comfort. The registry marks the study completed, but it reports no analysis for the primary outcome. Details of the statistical analysis plan, participant flow, adherence, and handling of withdrawals are not reported in the registry record.
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.
Before assignment: 26 participants were enrolled, 25 completed the study. One participant withdrew voluntarily after baseline measurements due to scheduling conflicts and was excluded.
Overall Study
| Stage | Intervention Group | Sham Group |
|---|---|---|
| STARTED | 13 | 13 |
| COMPLETED | 12 | 13 |
| NOT COMPLETED | 1 | 0 |
Reasons for not completing this period:
| Reason | Intervention Group | Sham Group |
|---|---|---|
| Withdrawal by Subject | 1 | 0 |
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 | Intervention Group | Sham Group | Total |
|---|---|---|---|---|
| Participants analysed | 12 | 13 | 25 | |
| Age, Continuous | years | 22.8 (SD 3.2) | 21.8 (SD 1.5) | 22.3 (SD 2.5) |
| Sex: Female, Male: Female | Participants | 12 | 13 | 25 |
| Sex: Female, Male: Male | Participants | 0 | 0 | 0 |
| Race and Ethnicity Not Collected | Participants | — | — | 0 |
| Height | centimeter | 169.8 (SD 7.8) | 167.1 (SD 6.8) | 168.3 (SD 7.3) |
| Weight | kilogramm | 64.6 (SD 5.6) | 62.4 (SD 13.0) | 63.5 (SD 10.0) |
| Body mass index (bmi) | kg/m^2 | 22.5 (SD 1.6) | 22.3 (SD 3.7) | 22.4 (SD 2.8) |
| Lower body fat | percent | 30.3 (SD 2.4) | 27.7 (SD 7.8) | 29.0 (SD 5.9) |
6. Primary Endpoint
The registry lists the primary outcome as Maximal Isometric Force of the Back Extensors, measured over Baseline, 3 weeks, 6 weeks.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | Newton |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is maximal isometric force of the back extensors, measured in Newton. The registry identifies the summary measure as a mean with standard deviation. The measurement is made using the ILEX machine: participants fold their arms across the chest and perform a slow, continuous 2-3 s maximal-effort back extension against a fixed upper-back pad. Peak force is recorded electronically, and the higher of two trials is used for analysis.
This measure is intended to quantify the force produced during a standardized isometric effort. A consistent machine-based procedure can make comparisons across assessments more interpretable by defining the posture, effort, equipment, and value selected from the trials. Repeated assessment can describe how the measure changes during training, while comparison of the randomized groups can address whether those changes differ between the active-therapy and sham-therapy conditions.
That interpretation depends on having reported outcome values and a clear analysis comparing groups over time. Neither numerical endpoint results nor an estimated treatment contrast is reported in the registry record. The listed assessment times also differ from the follow-up schedule described in the summary. Thus, the measurement procedure is described, but the posted record does not allow the size or precision of any group difference in force to be evaluated.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record establishes the study question and broad design, but it does not provide numerical results for maximal isometric force. It lists no analyses. Consequently, there is no reported group mean, change from baseline, between-group contrast, confidence interval, or significance test to interpret. The record does not establish whether force increased, decreased, or differed between the intervention and sham groups.
The study is marked completed, but that status is distinct from reporting outcome data. The stated endpoint uses a continuous measure, summarized as a mean and standard deviation. Without those values, readers cannot judge the observed spread of measurements or how precisely a treatment contrast was estimated. No conclusion about the direction or magnitude of an effect can be drawn from the design description alone.
Two descriptions of assessment timing appear in the record. The primary outcome timeframe lists baseline, 3 weeks, and 6 weeks. The summary instead describes measurements after the ninth and eighteenth sessions, within a 9-week program. The registry does not explain how these schedules correspond, so the intended time basis for interpreting changes is unclear.
Enrollment is also described in two ways: the registry figure is 26, while the brief summary describes a cohort of 14. Their relationship is not explained. This makes it important not to treat either figure as a confirmed count for a particular analysis population or outcome assessment.
Randomization is useful because, when implemented appropriately, it can support a fair comparison between study groups. But the record does not report methods for generating or concealing allocation, which people were masked, participant flow, or the analysis population. Those details cannot be inferred from the labels randomized and double-masked.
In general, confidence intervals communicate the range of effect values reasonably compatible with the observed data under an analysis model; they do not appear in the reported record. A p-value, if available, would address compatibility with a specified null model, not the size or practical importance of an effect by itself. Neither a p-value nor a confidence interval is reported. The absence of those estimates means the uncertainty around any comparison cannot be assessed.
The record reports zero serious adverse events in each listed group, with the stated groups at risk shown in the safety information. These figures describe only the reported serious-event counts and do not supply efficacy evidence. They also do not establish that all possible harms were measured or reported. Overall, the posted information supports description of the planned comparison and measurement procedure, not a conclusion about treatment effects.
9. Statistical Methods Explained
The registry identifies the primary outcome as a continuous measure: maximal isometric force of the back extensors, recorded in Newton and summarized by a mean and standard deviation. A continuous measure can take different values across a range, rather than being limited to categories such as event versus no event. A mean describes the central value of a group’s observations; a standard deviation describes their spread. These are general statistical meanings, not reported results for this study.
What does randomization contribute?
In general, random allocation aims to make study groups comparable at the start, including with respect to factors that may not have been measured. If allocation is implemented as intended and the groups are followed and analyzed appropriately, differences in outcomes can be interpreted as evidence about the assigned study conditions with less concern about systematic baseline selection. Randomization does not guarantee that groups will be identical, especially in a small study, and it does not correct later problems such as differential loss to follow-up or outcome measurement differences.
The registry calls this trial randomized but does not report how the sequence was generated, how assignments were concealed, or how the process was implemented. The double-masked designation is also not accompanied by details about who was masked. These reporting gaps prevent evaluation of the practical safeguards behind the design labels.
How could repeated measurements be compared?
The endpoint is described at multiple assessment times. In general, a repeated-measures analysis can account for the fact that observations from the same participant are related, rather than treating them as independent. An analysis might estimate change over time within each group and compare the patterns between groups. The choice of model, covariance assumptions, baseline adjustment, and method for handling incomplete measurements can affect the estimate and its uncertainty.
The registry does not report the model or analysis strategy. It therefore cannot be assumed that a particular repeated-measures method, baseline adjustment, or comparison was used. The timing is also not fully consistent across the descriptions: the primary outcome lists baseline, 3 weeks, and 6 weeks, while the summary describes follow-ups after the ninth and eighteenth sessions. Clear timing is essential for interpreting a change estimate, since the assessment occasion defines what change is being measured.
Why do estimates and uncertainty matter?
In general, an effect estimate describes the size and direction of a comparison, while its confidence interval describes uncertainty around that estimate under the chosen statistical model. A narrow interval indicates greater precision than a wide interval, though precision alone does not determine whether an effect is important. A p-value addresses how compatible the observed data are with a specified null hypothesis and model. It does not measure the probability that the null hypothesis is true, and it does not replace an effect estimate or interval.
No primary-outcome estimates, confidence intervals, or p-values are reported in the registry record. The record lists zero analyses, so no numerical inferential result can be explained. The absence of a reported result is not evidence that the groups were equal; it means the record does not provide the analysis needed to assess a difference.
What is over-dispersion, and does it apply?
Over-dispersion is a general concern for count outcomes when the observed variability exceeds what a model assumes. It can lead to uncertainty estimates that are too small if ignored. The primary endpoint is a continuous force measurement, not a count outcome, so over-dispersion is not the central issue for the stated primary measure. The registry does not report a statistical model or diagnostics, and no claim about model adequacy can be made from the record.
How should planning illustrations be read?
Sample-size illustrations are planning aids, not evidence that a study had a particular probability of detecting its observed result. The stated illustration assumptions describe a two-sided significance level of 0.05, equal allocation, a normal approximation, and effects expressed as a stated fraction of the observed effect. Such calculations depend on their assumptions and are not the trial’s own design justification. The registry does not report a sample-size justification or explain whether these assumptions informed the study’s planning. In particular, an illustration based on an observed effect should not be described as observed power.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary outcome and multiple secondary outcomes, including endurance, muscle thickness, lumbar flexibility and range of motion, and several participant ratings. It does not report a statistical plan specifying which comparisons were primary, how repeated assessment times were handled, or whether any adjustment for multiple testing was planned. When many outcomes or time-point comparisons are examined, the chance of at least one apparently unusual finding can increase. General approaches include prespecifying a primary contrast, controlling the family-wise error rate, or interpreting secondary analyses as exploratory. The record does not say which approach, if any, was used.
The stated primary-outcome timing is baseline, 3 weeks, and 6 weeks, whereas the summary describes follow-ups after the ninth and eighteenth sessions. The record does not reconcile these schedules. It also does not report whether every planned assessment was completed or which time points contributed to any analysis.
Missing-data methods and analysis populations are not reported in the registry record. There is no description of exclusions, withdrawals, imputation, or whether participants were analyzed according to their randomized group. These details matter because incomplete follow-up can affect the group comparison, particularly if missingness differs between groups or relates to outcomes.
The record reports no analyses for the primary outcome. It therefore provides no basis for assessing multiplicity adjustments, missing-data handling, or the population included in an effect estimate. The absence of this information should be treated as a reporting limitation, not as evidence that all outcomes were measured or all participants contributed data.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Intervention Group | 0 | 12 | 0.0% |
| Sham Group | 0 | 13 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Intervention Group | 0 of 12 |
| Sham Group | 0 of 13 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Intervention Group | 0 of 12 |
| Sham Group | 0 of 13 |
The registry lists zero serious adverse events in the intervention group, with 12 at risk, and zero in the sham group, with 13 at risk. It also lists zero deaths in both groups. These are the serious-event figures recorded for the groups. The registry reports zero other adverse events in each group as well, using the listed at-risk counts of 12 and 13.
A zero count means that no event of the specified type is recorded in that group in this registry entry. It does not establish that the intervention has no risks, nor does it rule out events that were not captured, classified, or entered. The record does not give further detail on how adverse events were collected, the observation period for safety reporting, or whether all participants were assessed for harms.
The at-risk figures are not the same as a complete account of safety surveillance or participant follow-up. Because the record does not explain their relationship to the enrollment figure of 26 and the summary’s cohort of 14, they should not be used to infer a total study population. The serious-event counts should be read descriptively and separately from the unreported primary-outcome results.
12. What the Result Does, and Does Not, Mean
The record describes a randomized comparison of CRET therapy plus ILEX training with sham CRET therapy plus ILEX training in healthy participants without prior ILEX training experience, as stated in the summary. It identifies maximal isometric force of the back extensors as the primary endpoint and describes how that measure was obtained. It also lists secondary measures and reports serious adverse-event counts.
What the record does not establish is the effect of adding active CRET therapy. There are no reported primary-outcome values, between-group estimates, confidence intervals, or p-values, and the record lists no analyses. Therefore, it cannot show whether force changed, whether change differed by group, or how precise any difference might be. Study completion status does not fill this reporting gap.
The design could in principle support a comparison of the two assigned conditions, but interpretation would also require clarity about assessment timing, participant flow, analysis populations, and statistical methods. The registry’s primary timeframe and the summary’s follow-up schedule differ, and the enrollment figure and cohort description are not reconciled. These issues constrain interpretation even before considering the absence of numerical results.
The reported zero serious adverse events are limited to the event counts recorded in the registry. They do not show that all possible adverse effects were absent or fully assessed. Similarly, the study’s listed secondary outcomes indicate topics of measurement, not evidence of changes in those outcomes.
The appropriate reading is therefore descriptive: the registry outlines the study question, intervention conditions, measurement procedure, and some safety counts, but it does not provide outcome analyses sufficient to determine an effect or its uncertainty. No treatment recommendation or conclusion about benefit can be drawn from this record alone.
13. Why This Trial Matters Statistically
This study raises a focused statistical question: whether the group receiving CRET therapy with ILEX training has a different pattern of maximal isometric back-extensor force from the group receiving sham CRET therapy with the same training. Because both groups train, the comparison is designed to distinguish the active-therapy condition from the shared training program and study context, rather than simply comparing training with no training.
The endpoint is a continuous, machine-recorded measure, and the summary describes a standardized effort procedure. For such an endpoint, interpretation depends not only on the average values but also on variability, the time points analyzed, and the uncertainty around the between-group comparison. None of those outcome estimates are reported in the registry record.
The record also illustrates why clear alignment between the study schedule and endpoint timeframe matters. Baseline, 3 weeks, and 6 weeks are listed for the primary outcome, while the summary describes follow-up after the ninth and eighteenth sessions in a 9-week program. Without clarification, readers cannot tell how those assessment descriptions map to the intended analysis.
Finally, differences between the enrollment figure and the cohort description, and the absence of reported analyses, limit what can be learned from the registry entry. A completed status, a randomized design, and a detailed measurement procedure are useful context, but they do not substitute for results. Statistical interpretation requires reported estimates and methods, together with enough information to understand who contributed data and how comparisons were made.
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 most important limitation for interpreting this trial is that the registry record does not report numerical primary-outcome results or analyses. Without outcome summaries and a between-group estimate, there is no way to assess effect direction, magnitude, or precision. No confidence interval or significance test is reported.
The record contains unresolved differences in study descriptions. Enrollment is listed as 26, while the summary describes a cohort of 14. The primary outcome timeframe is baseline, 3 weeks, and 6 weeks, while the summary describes measurements after the ninth and eighteenth sessions in a 9-week program. The record does not explain either difference. These are reporting ambiguities; they do not establish which description is correct.
Information about randomization implementation, allocation concealment, masking roles, participant flow, adherence, withdrawals, analysis populations, and missing-data handling is not reported in the registry record. A statistical analysis plan, sample-size justification, and approach to multiple outcomes or time points are also not reported. As a result, the robustness of any intended comparison cannot be evaluated from this entry.
The summary describes healthy participants without prior ILEX experience, which limits the population described by the study and does not establish how results would apply to other populations. However, because numerical findings are absent, even conclusions for the described participants cannot be drawn. The safety entry gives event counts but does not explain ascertainment or follow-up. These limitations are specific to what the registry reports and should not be treated as proof that unreported procedures or results do not exist elsewhere.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: The Effect of Diathermy Therapy on Isolated Lumbar Extension (ILEX) Training — NCT06852872.
- Registry record last updated 2026-10-30; status last verified 2026-10.
- Results first posted 2026-10-30.
- 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.
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18. Record Summary
The registry describes a completed, randomized, double-masked, parallel-group study of CRET therapy with ILEX training compared with sham CRET therapy with ILEX training. The primary outcome is maximal isometric force of the back extensors, measured in Newton using the ILEX machine and summarized as a mean with standard deviation.
The summary describes a 9-week program with a total of 18 sessions. The primary-outcome timeframe and the summary’s follow-up schedule are not aligned, and the enrollment figure differs from the cohort size described in the summary. The registry does not explain these discrepancies.
No primary-outcome analysis or numerical result is reported. The record lists zero serious adverse events and zero deaths in both groups. The statistical methods, analysis populations, missing-data procedures, and multiplicity approach are not reported in the registry record.