Functional sit-to-stands evoke greater neuromuscular activation than orthopaedic bed exercises in healthy older adults

Abstract

OBJECTIVE: To compare EMG activity of the hip and thigh muscles during traditional static bed exercises and the sit-to-stand exercise in healthy older adults. METHODS: Twenty-four healthy, older adults (8 male; age 65±7 yrs) performed four static rehabilitation exercises: isometric contractions of the gluteal, abductor, inner quadriceps and quadriceps (ten, ~5 s submaximal contractions, with 60 rests), and the sit-to-stand test. Electromyographic (EMG) activity was recorded from the rectus femoris, vastus medialis, gluteus medius, biceps femoris and gluteus maximus, and root mean square-processed (RMS) in this observational preliminary study. Handgrip strength, 10 m walking speed and hamstring-quadriceps ratio represented participant characteristics. RESULTS: Hip and thigh muscles were activated differently between the isometric bed and sit-to-stand exercises. Greatest RMS activity was shown in the chair rising phase of the sit-to-stand exercise. No bed exercise exceeded the muscle RMS activity required to perform a sit-to-stand, and only for sit-to-stands were all muscles activated over 40% of maximal; the level required to stimulate muscle strength adaptation. CONCLUSIONS: Functional daily activities, such as sit-to-standing, produce greater muscle activity than static bed exercises in healthy older adults. Sit-to-stands should be included in exercise and rehabilitation programs for older adults, to evoke sufficient levels of neuromuscular activation for muscle strength adaptation.