Investigating the relationship between spinal alignment and trunk muscle strength, sitting balance and function in spinal cord injury.

Objectives: This study aimed to investigate the relationship between spinal alignment and trunk muscle strength, sitting balance and functionality in individuals with spinal cord injury.

Methods: This study included 46 individuals with spinal cord injury (SCI) at T7 or below (AIS A or B) (mean age: 38.93 ± 14.43). Spinal alignment in a sitting posture was assessed using the DIERS Formetric Functional Spine and Posture Analysis System, while trunk muscle strength was measured with the DIERS Myoline Isometric Muscle Force Analysis System. Trunk balance was evaluated using the Trunk Control Test (TCT), Function in Sitting Test (FIST), and Modified Functional Reach Test (mFRT). Functional ability and independence were assessed with the Spinal Cord Independence Measure (SCIM-III).

Results: The analysis of the relationship between spinal alignment and trunk isometric muscle strength revealed a moderate positive correlation between trunk extensor strength and trunk length (r_s = -0.502) and a moderate negative correlation with vertebral rotation (+max) (r_s = -0.555). Also, a moderate negative correlation was found between trunk flexor strength and vertebral rotation (+max) (r_s = -0.480). No correlation was found between the spinal alignment and balance and functionality.

Conclusions: This study shows that trunk extensor strength is significantly associated with spinal alignment parameters, such as vertebral rotation and trunk length, in individuals with spinal cord injury. However, no relationship was found between spinal alignment and sitting balance or functional performance. These results suggest that combining postural assessment and trunk strengthening in rehabilitation may help improve posture and mobility.