Electrically induced muscle contractions influence bone density decline after spinal cord injury

Richard K Shields; Shauna Dudley-Javoroski; Laura A Frey Law

doi:10.1097/01.brs.0000201303.49308.a8

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Electrically induced muscle contractions influence bone density decline after spinal cord injury

Journal article

Peer reviewed

Electrically induced muscle contractions influence bone density decline after spinal cord injury

Richard K Shields, Shauna Dudley-Javoroski and Laura A Frey Law

Spine (Philadelphia, Pa. 1976), Vol.31(5), pp.548-553

03/01/2006

DOI: 10.1097/01.brs.0000201303.49308.a8

PMCID: PMC3270313

PMID: 16508550

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Abstract

Longitudinal repeated-measures; within-subject control. We examined the extent to which an isometric plantar flexion training protocol attenuates bone loss longitudinally after SCI. After spinal cord injury (SCI), bone mineral density (BMD) of paralyzed extremities rapidly declines, likely because of loss of mechanical loading of bone via muscle contractions. Six individuals with complete paralysis began a 3-year unilateral plantar flexor muscle activation program within 4.5 months after SCI. The opposite limb served as a control. Compliance with recommended dose was > 80%. Tibia compressive force was > 140% of body weight. Bilateral hip and untrained tibia BMD declined significantly over the course of the training. Lumbar spine BMD showed minimal change. Percent decline in BMD (from the baseline condition) for the trained tibia (approximately 10%) was significantly less than the untrained tibia (approximately 25%) (P < 0.05). Trained limb percent decline in BMD remained steady over the first 1.5 years of the study (P < 0.05). Compressive loads of approximately 1 to 2 times body weight, induced by muscle contractions, partially prevent the loss of BMD after SCI. Future studies should establish dose-response curves for attenuation of bone loss after SCI.

Compressive Strength - physiology

Bone Density

Spinal Cord Injuries - metabolism

Humans

Male

Muscle, Skeletal - physiology

Weight-Bearing - physiology

Electric Stimulation Therapy - methods

Bone and Bones - metabolism

Muscle Contraction - physiology

Adult

Female

Spinal Cord Injuries - physiopathology

Tibia - metabolism

Longitudinal Studies

Isometric Contraction - physiology

Details

Title: Subtitle: Electrically induced muscle contractions influence bone density decline after spinal cord injury
Creators: Richard K Shields - Graduate Program in Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, IA 52242-1190, USA. richard-shields@uiowa.edu
Shauna Dudley-Javoroski
Laura A Frey Law
Resource Type: Journal article
Publication Details: Spine (Philadelphia, Pa. 1976), Vol.31(5), pp.548-553
DOI: 10.1097/01.brs.0000201303.49308.a8
PMID: 16508550
PMCID: PMC3270313
NLM abbreviation: Spine (Phila Pa 1976)
ISSN: 0362-2436
eISSN: 1528-1159
Publisher: Lippincott Williams & Wilkins; United States
Grant note: R01 HD039445 / NICHD NIH HHS R01-HD 39445 / NICHD NIH HHS R01 HD039445-04 / NICHD NIH HHS
Language: English
Date published: 03/01/2006
Academic Unit: Orthopedics and Rehabilitation; Nursing; Physical Therapy and Rehabilitation Science
Record Identifier: 9984047680602771

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