Richard K Shields1, Shauna Dudley-Javoroski. 1. Graduate Program in Physical Therapy and Rehabilitation Science, The University of Iowa, Iowa City, IA 52242-1190, USA. richard-shields@uiowa.edu
Abstract
OBJECTIVE: The purpose of this study was to determine whether long-term electrical stimulation training of the paralyzed soleus could change this muscle's physiological properties (torque, fatigue index, potentiation index, torque-time integral) and increase tibia bone mineral density. METHODS: Four men with chronic (>2 years) complete spinal cord injury (SCI; American Spinal Injury Association classification A) trained 1 soleus muscle using an isometric plantar flexion electrical stimulation protocol. The untrained limb served as a within-subject control. The protocol involved ~ 30 minutes of training each day, 5 days a week, for a period of 6 to 11 months. Mean compliance over 11 months of training was 91% for 3 subjects. A fourth subject achieved high compliance after only 5 months of training. Mean estimated compressive loads delivered to the tibia were approximately 110% of body weight. Over the 11 months of training, the muscle plantar flexion torque, fatigue index, potentiation index, and torque-time integral were evaluated periodically. Bone mineral density (dual-energy x-ray absorptiometry) was evaluated before and after the training program. RESULTS: The trained limb fatigue index, potentiation index, and torque-time integral showed rapid and robust training effects (P<.05). Soleus electrical stimulation training yielded no changes to the proximal tibia bone mineral density, as measured by dual-energy x-ray absorptiometry. The subject with low compliance experienced fatigue index and torque-time integral improvements only when his compliance surpassed 80%. In contrast, his potentiation index showed adaptations even when compliance was low. CONCLUSIONS: These findings highlight the persistent adaptive capabilities of chronically paralyzed muscle but suggest that preventing musculoskeletal adaptations after SCI may be more effective than reversing changes in the chronic condition.
OBJECTIVE: The purpose of this study was to determine whether long-term electrical stimulation training of the paralyzed soleus could change this muscle's physiological properties (torque, fatigue index, potentiation index, torque-time integral) and increase tibia bone mineral density. METHODS: Four men with chronic (>2 years) complete spinal cord injury (SCI; American Spinal Injury Association classification A) trained 1 soleus muscle using an isometric plantar flexion electrical stimulation protocol. The untrained limb served as a within-subject control. The protocol involved ~ 30 minutes of training each day, 5 days a week, for a period of 6 to 11 months. Mean compliance over 11 months of training was 91% for 3 subjects. A fourth subject achieved high compliance after only 5 months of training. Mean estimated compressive loads delivered to the tibia were approximately 110% of body weight. Over the 11 months of training, the muscle plantar flexion torque, fatigue index, potentiation index, and torque-time integral were evaluated periodically. Bone mineral density (dual-energy x-ray absorptiometry) was evaluated before and after the training program. RESULTS: The trained limb fatigue index, potentiation index, and torque-time integral showed rapid and robust training effects (P<.05). Soleus electrical stimulation training yielded no changes to the proximal tibia bone mineral density, as measured by dual-energy x-ray absorptiometry. The subject with low compliance experienced fatigue index and torque-time integral improvements only when his compliance surpassed 80%. In contrast, his potentiation index showed adaptations even when compliance was low. CONCLUSIONS: These findings highlight the persistent adaptive capabilities of chronically paralyzed muscle but suggest that preventing musculoskeletal adaptations after SCI may be more effective than reversing changes in the chronic condition.
Authors: Richard K Shields; Janet Schlechte; Shauna Dudley-Javoroski; Bradley D Zwart; Steven D Clark; Susan A Grant; Vicki M Mattiace Journal: Arch Phys Med Rehabil Date: 2005-10 Impact factor: 3.966
Authors: Shauna Dudley-Javoroski; Andrew E Littmann; Shuo-Hsiu Chang; Colleen L McHenry; Richard K Shields Journal: Arch Phys Med Rehabil Date: 2011-02 Impact factor: 3.966
Authors: M Invernizzi; S Carda; M Rizzi; E Grana; D F Squarzanti; C Cisari; C Molinari; F Renò Journal: Spinal Cord Date: 2015-04-21 Impact factor: 2.772
Authors: C M Cirnigliaro; M J Myslinski; M F La Fountaine; S C Kirshblum; G F Forrest; W A Bauman Journal: Osteoporos Int Date: 2016-12-05 Impact factor: 4.507
Authors: Ashraf S Gorgey; David R Dolbow; James D Dolbow; Refka K Khalil; David R Gater Journal: J Spinal Cord Med Date: 2014-07-08 Impact factor: 1.985