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Skeletal Muscle Strength and Functional Ability in Older Adults Following 10 Days of Bed Rest
Author(s) -
Lombeida Juan Ignacio,
Symons Brock,
PaddonJones Douglas,
Kortebein Patrick,
Ferrando Arny,
Ronsen Ola,
Wolfe Robert,
Evans William,
Protas Elizabeth
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a382-c
Subject(s) - muscle strength , physical medicine and rehabilitation , balance (ability) , bed rest , medicine , gait , plantar flexion , rest (music) , physical therapy , leg muscle , population , ankle , surgery , cardiology , environmental health
Older adults tend to be less physically active than the general population. During the course of treatment for illness, trauma or major surgery, activity is further impaired by bed rest and may lead to declines in muscle strength and functional ability beyond those of normal aging. We evaluated the effects on muscle strength and overall function following 10 days of bed rest in healthy older adults (n=9, 67±5yrs). Primary outcome measures included leg press 1‐RM strength, unilateral knee extensor 1‐RM strength, and standing plantar flexion strength. Functional ability was assessed by the Short Physical Performance Battery (SPPB) (timed balance, timed 4m walk and timed chair rise) and by summing 4 tests (gait speed, timed floor transfer, timed 5‐step test and gait endurance). Ten days of bed rest decreased unilateral knee extensor 1‐RM strength by 12±12% ( p =0.02) and standing plantar flexion strength by 17±10% ( p =0.02); while leg press 1‐RM strength was unaffected ( p =0.08). Functional ability ( p =0.04) and the SPPB ( p =0.59) were unchanged. Ten days of bed rest resulted in decreased strength of the knee extensors and plantar flexors without an impairment of functional ability that could be assessed by our measures. This data suggests either the need for more sensitive tests of functional ability or the existence of a muscle strength threshold that must be breached before functional impairment occurs. AG 023591, MO1 RR 00073, RR14288