Improving Functional Independence in People with Incomplete Spinal Cord Injury through Eccentric Resistance Training

Abstract

Individuals with an incomplete spinal cord injury (iSCI) experience physical and functional challenges from decreased metabolic efficiency and maximal oxygen consumption and musculoskeletal wasting. To minimize the impact of these changes, individuals with iSCI are encouraged to participate in physical activities to promote overall health and skeletal muscle development. Eccentric resistance training (ERT) is a promising modality for individuals with iSCI due to its inherently low metabolic cost and potential to stimulate musculoskeletal hypertrophy. To investigate the benefits of this training modality in this population, participants with iSCI to the cervical (n = 6), thoracic (n = 4), or lumbar (n = 1) region were included in the current sample. In the first study, changes in muscular strength (eccentric and isometric) and daily step physical activity (PA) were assessed following twice weekly sessions of ERT for 12 weeks. Secondly, data were evaluated to assess improved walking function following the ERT intervention. Participants completed a 10 meter walk test (10MWT; walking speed), timed up and go (TUG; mobility), Walking Index for Spinal Cord Injury (WISCI; walking independence), and Spinal Cord Independence Measure (SCIM; at home function) at baseline, after week 6 of training, and following the training program.

Following the ERT intervention, eccentric strength (p = .009; d = .473) and isometric strength (p = .005; d = .689) improved, but there was no change in daily step PA (p = .092; d = .256). Relative to function, participants improved walking speed (p = .005, d = .23), TUG mobility (p = .034, d = .62), and WISCI performance (p = .004, d = .73) as a result of the ERT. However, SCIM outcomes did not change (p = .20, d = .18). Further, 10MWT (r = .735, p = .01), TUG (r = -.708, p = .015), and WISCI (r = .829, p = .002) outcomes correlated with daily step PA, respectively, after 6 weeks of ERT. Correlations with daily step PA continued for TUG (r = -.689, p = .019) and 10MWT (r = .694, p = .018), respectively, post-test.

Overall, ERT improved measures of strength, walking speed, mobility, and independence in individuals with an iSCI. This information may help clinicians justify the implementation of ERT when seeking to improve strength and walking function in individuals with neurological disorders. Further, these improvements can be produced with low therapist and client burden. Future investigations seeking to determine the effectiveness of ERT on at home function may consider a measurement tool more sensitive than the SCIM.