Hip muscle strength, dynamic balance and functional capacity of community-dwelling older adults aged 60 and older: A cross-sectional study.

The objective of the present study was to evaluate the association of hip muscle strength, dynamic balance and functional capacity in the older adults aged 60 to 79 years and older adults aged 80 years and older. A total of 191 community-dwelling older adults participated in this study. Isometric muscle strength was quantified as the peak torque (PT), measured using an isokinetic dynamometer. Functional capacity was determined by the forward step test (ST) and the dynamic balance by the tandem gait (TG) test. The hip flexor, extensor, abductor and adductor PT in the older adults aged 60 to 79 years had a positive influence on the execution of the step test (p < 0.05). The peak adductor torque did not show a significant association with tandem gait (p = 0.649). In older adults aged 80 years and older, the peak adductor torque was the only one that showed an association with the performance of the ST (p = 0.001) and TG (p = 0.024) tests. The hip adductors may have a higher contribution in adults aged 80 years and older during the execution of clinical tests. These findings are relevant to clinical practice as they can help in the development of appropriate physical exercise programs targeting older adults of different age groups.

The effect of unilateral muscle fatigue of hip abductor muscles on balance and functional capacity in community-dwelling older women.

BACKGROUND: Hip abductor muscles are important for the maintenance of postural stability, mainly on the mediolateral direction and unipodal support conditions. The objective of the present study was to evaluate the effect of unilateral induced fatigue of hip abductor muscles on balance and functional capacity of older women. METHODS: The study included physically independent women aged 60-75 years. We assessed static balance with the single limb stance test (SLS) and evaluated functional capacity with the maximum gait speed (MGS) and step test (ST). We ran the protocol of hip abductor muscle fatigue with a Biodex isokinetic dynamometer. Assessment of balance and functional capacity happened before and after the muscle fatigue protocol. We applied the t-test for repeated measures to determine whether unilateral hip abductor muscle fatigue influences the performance in the tests (SLS, MGS and ST). RESULTS: The protocol of hip abductor muscle fatigue negatively affected all three evaluated tasks: SLS (p = 0.000), ST (p = 0.000) and MGS (p = 0.000). However, the single limb stance test was the most task affected (effect size = 0.51, pre- and post-fatigue difference = 28.1 %). CONCLUSION: After the unilateral muscle fatigue of hip abductors, we observed the worst performance on clinical tests, mainly regarding the SLS test, which shows the involvement of hip abductors during usual motor tasks. However, the small magnitude of the limitation of functional tests (MGS and ST) suggests the presence of postural compensations.

Diagnostic Accuracy of Clinical Tests for the Indirect Assessment of Hip Abductor Muscle Strength in Community-Dwelling Older Women.

OBJECTIVE: The objective of this study was to determine the accuracy of 3 clinical tests (lateral step [LS], tandem gait [TG], and single-leg stance [SS]) in identifying older women with reduced hip abductor muscle strength and to determine the post-test probability of each test and of their combination in changing the certainty of diagnosis. METHODS: In this cross-sectional study, a total of 123 older women received clinical testing to obtain the variables LS height, time for TG execution, percentage of errors in TG, and time of permanence on SS and were tested for isometric hip abductor peak torque using an isokinetic dynamometer. Only the dominant lower limb was evaluated. Multiple linear regression analysis with adjustment was performed to determine the association among variables, followed by the receiver operating characteristic curve to identify clinical variables that can discriminate older women with reduced abductor muscle strength. Post-test probability was then calculated based on the receiver operating characteristic curve data. RESULTS: Although the 4 clinical variables showed correlation with abductor peak torque, only LS and TG time were able to discriminate reduced abductor muscle strength with low accuracy (area under the curve was between 0.5 and 0.7). However, the combination of LS and TG time increased post-test probability from 47% (prevalence of weakness in the population) to 76% when both tests were positive and reduced it from 47% to 18% when both tests were negative. CONCLUSION: The combination of the LS test and TG time is useful for the indirect assessment of hip abductor strength in community-dwelling older women. IMPACT: Hip abductor muscle strength is extremely important for function in older women. This study presents clinicians with simple, fast, and inexpensive methods for assessing hip abductor muscle strength.