Ty B Palmer1, Ryan M Thiele, Eric C Conchola, Douglas B Smith, Brennan J Thompson. 1. 1Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, Texas. 2Department of Health and Human Performance, Oklahoma State University, Stillwater, Oklahoma. 3Department of Wellness, Oklahoma State University, Stillwater, Oklahoma. 4Neuromuscular Research Laboratory, Utah State University, Logan, Utah.
Abstract
BACKGROUND: Maximal and rapid strength characteristics of the knee extensor and flexor muscles play an important role in fall prevention and walking-related performances; however, few studies have investigated the ability of these variables to identify chair-rise performances in very old adults. PURPOSE: To examine the effectiveness of maximal and rapid isometric strength characteristics of the knee extensors and flexors to differentiate between very old adults who are able (higher functioning) versus unable (lower functioning) to independently rise from a chair. METHODS: Nine higher functioning (age, 87 ± 6 years) and 6 lower functioning (age, 89 ± 6 years) very old adults performed 2 isometric maximal voluntary contractions of the knee extensors and flexors. Peak moment and absolute and relative rate of moment development (RMD) at the early (0-50 ms) and late (0-200 ms) phases of muscle contraction were examined during each maximal voluntary contraction. RESULTS: Absolute and relative RMD values at 0 to 50 ms were greater (P = .02 and .03, respectively) in the higher functioning than in the lower functioning individuals for both the knee extensors and flexors. However, no group-related differences (P = .39-.58) were observed in either muscle group for peak moment or absolute and relative RMD at 0 to 200 ms. CONCLUSIONS: Early rapid moment production of the knee extensors and flexors may be an effective measure for discriminating between very old adults of different chair-rise performance abilities. Physical therapists and other practitioners may use these findings to help with the identification and early detection of older adults who are at a high risk for functional decline.
BACKGROUND: Maximal and rapid strength characteristics of the knee extensor and flexor muscles play an important role in fall prevention and walking-related performances; however, few studies have investigated the ability of these variables to identify chair-rise performances in very old adults. PURPOSE: To examine the effectiveness of maximal and rapid isometric strength characteristics of the knee extensors and flexors to differentiate between very old adults who are able (higher functioning) versus unable (lower functioning) to independently rise from a chair. METHODS: Nine higher functioning (age, 87 ± 6 years) and 6 lower functioning (age, 89 ± 6 years) very old adults performed 2 isometric maximal voluntary contractions of the knee extensors and flexors. Peak moment and absolute and relative rate of moment development (RMD) at the early (0-50 ms) and late (0-200 ms) phases of muscle contraction were examined during each maximal voluntary contraction. RESULTS: Absolute and relative RMD values at 0 to 50 ms were greater (P = .02 and .03, respectively) in the higher functioning than in the lower functioning individuals for both the knee extensors and flexors. However, no group-related differences (P = .39-.58) were observed in either muscle group for peak moment or absolute and relative RMD at 0 to 200 ms. CONCLUSIONS: Early rapid moment production of the knee extensors and flexors may be an effective measure for discriminating between very old adults of different chair-rise performance abilities. Physical therapists and other practitioners may use these findings to help with the identification and early detection of older adults who are at a high risk for functional decline.