Effect of a Spinal Orthosis With Leaf Spring and Programmable Local Vibration on Kyphosis Angle and Trunk Muscle Strength in Hyperkyphosis: Development and Feasibility Study
Bibliographic record
Abstract
Abstract Background The application of spinal orthoses and local vibration in the treatment of hyperkyphosis is a developing concept. Further research is needed to determine the impact of leaf springs and local vibration techniques on the neuromusculoskeletal system. Objective This study aimed to evaluate the effect of the simultaneous application of a leaf spring and a programmed local vibration system in a spinal orthosis on thoracic kyphosis angle (TKA) and the function of trunk flexor and extensor muscles. Methods We used a soft thoracolumbar orthosis as a base for 2 parallel leaf spring bars made from AISI (American Iron and Steel Institute) 1075 steel (45 cm × 2 cm × 2 mm each). We added 4 solenoid actuators (60 g each) housed in 2 units positioned 12 cm apart, generating 20 N vertical force at 8 Hz frequency with 10 mm free displacement. A programmable Arduino microcontroller delivered 10-second vibration bursts followed by 5-minute rest intervals, repeated for 12 cycles per session, applied every other day. One participant with hyperkyphosis (baseline TKA=47.24°) used this device for 4 weeks. Outcomes included TKA (measured by photogrammetry) and trunk muscle function (assessed under isometric, isotonic, and isokinetic conditions). Feasibility outcomes included adherence, wear time, and adverse events. Results Bench testing confirmed an 8 Hz vibration frequency, a 10 mm free displacement, and an on-body contact pressure of 9.5 N/cm² (95 kPa). In the short-term assessment (N=10), mean acceptability scores were 7.95 (SD 0.83) for appearance and 7.6 (SD 0.07) for comfort, and no skin-related adverse events occurred. In the 4-week single-participant pilot (N=1), adherence was 100% (12/12 sessions completed), mean daily wear time was 1.4 (SD 0.3) hours, and no adverse events were reported. TKA decreased from 47.24° to 45.81° (change: −1.43°), which did not exceed the minimal detectable change (4.62°). Pre-post changes in muscle function outcomes are reported descriptively. Conclusions A semirigid thoracolumbar orthosis with integrated programmable vibration (8 Hz, 20 N free force) is technically feasible, showing reliable bench performance. Short-term assessment in 10 participants indicated acceptable comfort and appearance with no immediate safety concerns. The 4-week single-participant pilot demonstrated 100% adherence and no adverse events. The observed 1.43° kyphosis reduction was not clinically meaningful (below minimal detectable change). Larger controlled studies are needed to determine whether this device improves muscle function or spinal alignment.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".