The effect of spinal orthosis on trunk muscle force control in hyperkyphotic elderly

Background: The back extensor muscles are the main spinal supportive factors which function establishes spinal stability and erect posture of the spine. Spine deviation from the ideal alignment, like abnormal increase in the forward curvature of the thoracic spine may cause changes in the trunk muscle activity which can lead to a change in the spinal proprioception. It seems that the corrected spinal alignment as a result of an orthotic treatment course facilitates the back muscles activity and improve proprioception. The present study aimed to investigate the changes occurring in thoracic kyphosis, trunk extensor muscle strength and trunk extensor force sense after using the Spinomed orthosis in elderly people with hyperkyphosis. Methods: Twenty-six elderly people with hyperkyphosis who met the eligibility criteria participated in this preliminary study at School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran, from August to November of 2017. Subjects were randomly allocated to the experimental (wearing the orthosis with maintaining the daily physical activities) and control (maintaining daily physical activities) groups. Degree of kyphosis, absolute error of force sense and trunk extensor muscle strength were measured in all participants before and after intervention for 9 weeks. Results: Thirteen elderly people with 63.85±4.63 years old in the experimental group and thirteen elderly people with 66.92±3.25 years old were participated in data analysis. The results showed significant reduction in degree of kyphosis (P<0.001) and absolute error of force sense (P=0.001), and improvement of trunk extensor muscle strength (P=0.021) in the experimental group. Independent t-test results showed a significant difference between experimental and control groups with better outcomes in terms of posture correction (P<0.001) strength (P=0.002) and force sense (P=0.035) in the orthosis group. Conclusion: Using Spinomed orthosis for 2 months (2 hours per day) appears to have some benefit in terms of back extensor muscle strength and muscle force control. Also, Spinomed orthosis can be prescribed to improve spinal posture.