Search Results

The objectives of this study were to standardize measurement procedures and study the test-retest and interrater reliability of the belt-resisted method for measuring the lower extremity isometric strength of three muscle groups. The strength of 33 healthy, elderly, community-dwelling subjects was evaluated with a hand-held dynamometer using the belt-resisted method. Isometric strength testing of three muscle groups (hip flexors, knee extensors, and ankle dorsiflexors) was performed on two separate occasions, I week apart, by the same tester to determine test-retest reliability. The test results of two different examiners testing on different days were used to determine interrater reliability. Test-retest reliability was higher than interrater reliability. Test-retest reliability coefficients of the three muscle groups were high (J9-.95). For interrater reliability, intraclass correlation coefficients varied from .64 to .92. depending on the muscle group and side. For the two kinds of reliability, intraclass correlation coefficients increased from proximal to distal. The method for the hip muscle group should be modified to increase reliability of the measure.

This study evaluated the effects of a 4-month lower extremity strength-training program on mobility in older adults. Eighty-five older adults (43 experimental, ES, and 42 comparison, CS) with a mean age of 72.3 years served as participants. The ES strength-trained plantar flexors (PF), knee flexors (KF), and knee extensors (KE) 1 hr/day, 3 days a week for 4 months. Both the ES and CS were evaluated for PF, KF, and KE strength (1 RM) and the time required to complete floor rise, chair rise, 50-ft walk, and walking up and down stairs before and after the training intervention. The ES increased (p < .05) both absolute (51.9%) and relative strength (1 RM/body weight, 52.4%) after training. Only chair-rise and floor-rise tasks improved significantly after training. Baseline and posttraining mobility tasks predicted from 1 RMs had low to moderate R values. These results suggest that strength is necessary for mobility, but increasing strength above baseline provides only marginal improvement in mobility for reasonably fit older adults.

In order to obtain joint-specific baseline strength characteristics in older adults, clinicians and researchers must have knowledge regarding the relative stability of the various strength tests (the strength difference between repeated measures) and the number of prebaseline practice sessions required to obtain consistent data. To address these needs, the relative multiple-test stability and reliability associated with lower extremity isokinetic and 1-repetition-maximum (1RM) strength measures were assessed in a sample of older adults (N = 30, 65.2 ± 6.3 years), over 4 weeks (T1-T4). Isokinetic ankle plantar-flexion (30°/s) strength and 1RM ankle plantar-flexion, leg-press, and knee-flexion strength exhibited poor stability between Weeks T1 and T2 but stabilized between Weeks T2 and T3 and Weeks T3 and T4. The measures exhibited low incidence of injury and induced low levels of residual muscle soreness. Findings suggest that the 1RM measures require at least 1 prebaseline training session in order to establish consistent baseline performance and are more reliable than isokinetic ankle plantar-flexion tests.

It is unclear whether strength training (ST) or power training (PT) is the more effective intervention at improving muscle strength and power and physical function in older adults. The authors compared the effects of lower extremity PT with those of ST on muscle strength and power in 45 older adults (74.8 ± 5.7 yr) with self-reported difficulty in common daily activities. Participants were randomized to 1 of 3 treatment groups: PT, ST, or wait-list control. PT and ST trained 3 times/wk for 12 wk using knee-extension (KE) and leg-press (LP) machines at ~70% of 1-repetition maximum (1RM). For PT, the concentric phase of the KE and LP was completed “as fast as possible,” whereas for ST the concentric phase was 2–3 s. Both PT and ST paused briefly at the midpoint of the movement and completed the eccentric phase of the movement in 2–3 s. PT and ST groups showed significant improvements in KE and LP 1RM compared with the control group. Maximum KE and LP power increased approximately twofold in PT compared with ST. At 12 wk, compared with control, maximum KE and LP power were significantly increased for the PT group but not for the ST group. In older adults with compromised function, PT leads to similar increases in strength and larger increases in power than ST.

Community-based rehabilitative exercise programs might be an effective means to improve functional outcomes for hip-fracture patients. The purpose of this study was to evaluate the effectiveness of a community exercise program (CEP) for older adults recovering from hip fracture. Twenty-five older adults (mean age 80.0 ± 6.0 years; 24 women; 71 ± 23 days post–hip fracture) participated in this pilot study (17 exercise, 8 control). The CEP involved functional stepping and lower extremity–strengthening exercises. Control participants received only standard outpatient therapy. Measures of functional mobility, balance confidence, falls efficacy, lower extremity strength, and daily physical activity were evaluated at baseline and at 16 weeks. Improvements for self-reported physical activity, mobility, balance, and knee-extensor strength were observed for the CEP group. This study demonstrated that a CEP is beneficial for community-dwelling older adults post–hip fracture.