Abstract
Purpose
To investigate the effect of a semi-rigid backpack type thoracolumbar orthosis (TLO) on thoracic kyphosis angle (TKA) and potentially contributing factors of hyperkyphosis, including position sense and back muscle strength and endurance.
Method
This randomized, controlled trial was conducted on 48 older adults with hyperkyphosis, randomly allocated to an experimental or control group. The experimental group wore a semi-rigid TLO for 3 consecutive months. The control group received no external support or exercise. Thoracic kyphosis angle (TKA), joint position sense, back muscle strength and endurance were evaluated at the baseline and at the end of week 6 and week 12.
Results
The two-way (group × time) interactions were significant in terms of TKA (F = 37.88, p ≤ 0.001, ηp2 = 0.45), muscle strength (F = 26.005, p ≤ 0.001, ηp2 = 0.36), muscle endurance measured via load cell (F = 3.417, p = 0.039, ηp2 = 0.06), and endurance holding time of Ito test (F = 3.629, p = 0.045, ηp2 = 0.07). A further analysis using one-way repeated measures of ANOVA showed that TKA, muscle strength and endurance were significantly improved in the experimental group. Also, two-way interactions were significant for absolute error and variable error of trunk neutral repositioning test from a trunk flexed and/or extended position for global components and horizontal components trunk repositioning test.
Conclusion
Wearing a semi-rigid backpack type TLO even from an unknown brand for short periods during the day (e.g., 2–4 h) over 3 months not only modifies kyphotic posture but also can enhance back muscle performance in older adults with hyperkyphosis.
Prescription of a semi-rigid backpack type thoracolumbar orthosis for older adults has no adverse effects such as muscle weakness if it is applied for short periods during the day.
A semi-rigid backpack thoracolumbar orthosis can prevent position sense degradation in older adults with hyperkyphosis.
A semi-rigid backpack type thoracolumbar orthosis may counteract trunk flexion and kyphotic posture by applying the biomechanical principles of the three-point pressure system.
Improvement in spinal alignment resulting from wearing thoracolumbar orthosis should not occur in exchange for muscle deconditioning.
IMPLICATIONS FOR REHABILITATION
Acknowledgments
The authors would like to thank all participants for their valuable contributions.
Ethical approval
The study protocol was approved by the Research Ethics Committee at Iran University of Medical Sciences (IR.IUMS.REC.1398.435) and followed the principles of the Declaration of Helsinki. All participants signed a written consent before enrollment.
Trial registration
The trial was registered in the Iranian Registry of Clinical Trials (www.irct.ir) on 6th April 2020 as IRCT20190811044505N1.
Disclosure statement
No potential conflict of interest was reported by the author(s).