Sagittal Spinal Mobility and Back Extensor Muscle Function in Older Females with Age-Related Hyperkyphosis

Tayebeh Roghani; Amy Gladin; Saeed Talebian; Minoo  Khalkhali Zavieh; Hoda Niknam; Wendy B. Katzman

doi:10.18502/jmr.v16i2.9306

Tayebeh Roghani Department of Physical Therapy, Musculoskeletal Research Center, Faculty of Rehabilitation Sciences, Isfahan University of Medical Sciences, Isfahan, Iran.
Amy Gladin Chronic Pain Department, San Francisco Kaiser Permanente Medical Center, San Francisco CA, United States.
Saeed Talebian Department of Physiotherapy, School of Rehabilitation, Tehran University of Medical Sciences and Health Services, Tehran, Iran.
Minoo Khalkhali Zavieh Department of Physiotherapy, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Hoda Niknam Physiotherapy Research Center, Department of Physiotherapy, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Wendy B. Katzman Department of Physical Therapy and Rehabilitation Sciences, University of California San Francisco, San Francisco, CA, United States.

DOI: https://doi.org/10.18502/jmr.v16i2.9306

Keywords: Spinal range of motion, Hyperkyphosis, Muscle function, Aging

Abstract

Introduction: Spinal range of motion (ROM) is a potential and modifiable variable that may contribute to the maintenance of upright sagittal alignment. The present study aimed to compare spinal ROM in older females with and without hyperkyphosis and investigate associations between thoracic kyphosis and spinal ROM, back extensor strength (BES), and back extensor endurance (BEE).
Materials and Methods: Sagittal spinal curvature and ROM were measured with the Spinal Mouse. Also, BES and BEE were assessed with a load cell. Variables were compared between older females with and without hyperkyphosis with the independent sample t test. We used the Pearson correlation coefficient to calculate associations between variables. Multiple linear regression was used to find which variable is best associated with kyphosis.
Results: Lumbar and total spinal ROM were lower in the hyperkyphosis compared to the normal group (P<0.05). Thoracic kyphosis was associated with total lumbar ROM (r=-0.30, P=0.03), total spinal ROM (r=-0.35, P=0.01), BES (r=-0.73, P< 0.001), and BEE (r=-0.60, P< 0.001). Multiple linear regression analysis after adjusting for age, weight, and BMI showed that BES (P<0.001) and BEE (P=0.01) but not spinal ROM (P=0.16) were significantly associated with thoracic kyphosis.
Conclusion: Females with hyperkyphosis had lower spinal ROM than those with normal kyphosis. While thoracic kyphosis was significantly associated with total lumbar ROM, total spinal ROM, BES, and BEE, multivariate regression showed that ROM was not a significant contributor to thoracic kyphosis. BES and BEE were significant contributors to thoracic kyphosis and should be targeted in the rehabilitation of hyperkyphosis.