Effects of prophylactic knee bracing on lower extremity joint position and muscle activation during running

• Published in: The American journal of sports medicine 1993-09, Vol.21 (5), p.733-737
• Main Authors: Osternig, Louis R., Robertson, Rick N.
• Format: Article
• Language: English
• Subjects: Adult; Ankle Joint - anatomy & histology; Ankle Joint - physiology; Biological and medical sciences; Braces; Diseases of the osteoarticular system. Orthopedic treatment; Electromyography - methods; Equipment Design; Evaluation; Exercise Test; Hip Joint - anatomy & histology; Hip Joint - physiology; Humans; Hypermobility; Joint instability; Joints; Knee; Knee Joint - anatomy & histology; Knee Joint - physiology; Leg; Male; Medical research; Medical sciences; Medical supplies; Muscles - physiology; Muscular system; Orthopedic braces; Physiological aspects; Posture; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Running; Running - physiology; Space life sciences; Sports medicine; Weight-Bearing - physiology
• ISSN: 0363-5465; 1552-3365
• DOI: 10.1177/036354659302100518

The primary purpose of a prophylactic knee brace is to decrease injury potential without compromising joint function; however, the extent that these devices can alter knee muscle function is not clear. This study investigated effects of nonprescription prophylactic knee bracing on lower extremity joint position and muscle activation during running. Six healthy male col lege-aged recreational runners used a motor-driven treadmill under 6 conditions: fast or slow speeds, with and without wearing a prophylactic knee brace, and with and without wearing a weighted vest. Changes in hip, knee, and ankle joint position and electromyo graphic activity from 9 lower extremity muscles were monitored during the running cycle weightbearing phase. Results revealed significant changes (P < 0.05) in joint position and electromyographic activity for com parisons of slow versus fast, braced versus nonbraced, and weighted versus nonweighted conditions. From 83% to 89% of the braced and nonbraced comparisons generated significant differences in knee joint position while significant hip and ankle joint position changes occurred in 50% to 58% of comparisons. From 67% to 83% of braced and nonbraced comparisons for the 9 muscles produced significant differences in electromyo graphic activity. Findings suggest that neuromuscular control is altered when external prophylactic devices are applied.