Enhancing Muscle Force and Femur Compressive Loads Via Feedback-Controlled Stimulation of Paralyzed Quadriceps in Humans

Shauna DUDLEY-JAVOROSKI; Andrew E LITTMANN; Shuo-Hsiu CHANG; Colleen L MCHENRY; Richard K SHIELDS

doi:10.1016/j.apmr.2010.10.031

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Journal article

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Peer reviewed

Enhancing Muscle Force and Femur Compressive Loads Via Feedback-Controlled Stimulation of Paralyzed Quadriceps in Humans

Shauna DUDLEY-JAVOROSKI, Andrew E LITTMANN, Shuo-Hsiu CHANG, Colleen L MCHENRY and Richard K SHIELDS

Archives of physical medicine and rehabilitation, Vol.92(2), pp.242-249

2011

DOI: 10.1016/j.apmr.2010.10.031

PMCID: PMC3056337

PMID: 21272720

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https://www.ncbi.nlm.nih.gov/pmc/articles/3056337View

Open Access

Abstract

Objective: To compare paralyzed quadriceps force properties and femur compressive loads in an upright functional task during conventional constant-frequency stimulation and force feedback-modulated stimulation. Design: Crossover trial. Setting: Research laboratory. Participants: Subjects (N=13; 12 men, 1 woman) with motor-complete spinal cord injury. Interventions: Subjects performed 2 bouts of 60 isometric quadriceps contractions while supported in a standing frame. On separate days, subjects received constant-frequency stimulation at 20Hz (CONST) or frequency-modulated stimulation triggered by a change in force (FDBCK). During FDBCK, a computer algorithm responded to each 10% reduction in force with a 20% increase in stimulation frequency. Main outcome measures: A biomechanical model was used to derive compressive loads on the femur, with a target starting dose of load equal to 1.5 times body weight. Results: Peak quadriceps force and fatigue index were higher for FDBCK than CONST (P<.05). Within-train force decline was greater during FDBCK bouts, but mean force remained above CONST values (P<.05). As fatigue developed during repetitive stimulation, FDBCK was superior to CONST for maintenance of femur compressive loads (P<.05). Conclusions: Feedback-modulated stimulation in electrically activated stance is a viable method to maximize the physiologic performance of paralyzed quadriceps muscle. Compared with CONST, FDBCK yielded compressive loads that were closer to a targeted dose of stress with known osteogenic potential. Optimization of muscle force with FDBCK may be a useful tactic for future training-based antiosteoporosis protocols.

Neurology

Osteoporosis. Osteomalacia. Paget disease

Miscellaneous

Cerebrospinal fluid. Meninges. Spinal cord

Diseases of the osteoarticular system

Biological and medical sciences

Medical sciences

Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects)

Nervous system (semeiology, syndromes)

Details

Title: Subtitle: Enhancing Muscle Force and Femur Compressive Loads Via Feedback-Controlled Stimulation of Paralyzed Quadriceps in Humans
Creators: Shauna DUDLEY-JAVOROSKI - Physical Therapy and Rehabilitation Science, Carver College of Medicine, The University of Iowa, Iowa City, IA, United States
Andrew E LITTMANN - Physical Therapy and Rehabilitation Science, Carver College of Medicine, The University of Iowa, Iowa City, IA, United States
Shuo-Hsiu CHANG - Physical Therapy and Rehabilitation Science, Carver College of Medicine, The University of Iowa, Iowa City, IA, United States
Colleen L MCHENRY - Physical Therapy and Rehabilitation Science, Carver College of Medicine, The University of Iowa, Iowa City, IA, United States
Richard K SHIELDS - Physical Therapy and Rehabilitation Science, Carver College of Medicine, The University of Iowa, Iowa City, IA, United States
Resource Type: Journal article
Publication Details: Archives of physical medicine and rehabilitation, Vol.92(2), pp.242-249
DOI: 10.1016/j.apmr.2010.10.031
PMID: 21272720
PMCID: PMC3056337
NLM abbreviation: Arch Phys Med Rehabil
ISSN: 0003-9993
eISSN: 1532-821X
Publisher: Elsevier; New York, NY
Language: English
Date published: 2011
Academic Unit: Orthopedics and Rehabilitation; Physical Therapy and Rehabilitation Science
Record Identifier: 9984047626502771

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