title: Sit-to-stand test to evaluate knee extensor muscle size and strength in the elderly: a novel approach.
abstract: The present study examined whether a sit-to-stand score can be related to the force-generating capacity of knee extensor muscles. Fifty-seven subjects (28 men, 63.0+/-7.8 yrs, and 29 women, 64.2+/-7.5 yrs, means+/-SDs) performed a 10-repeated sit-to-stand test as fast as possible, on a steel molded chair. The time taken (T(sit-stand)) was measured with a manual stopwatch. The leg length (L), defined as the distance from the great trochanter of the femur to the malleolus lateralis, was measured using a tape. A power index of the test (P(sit-stand)) was calculated by using the following equation: P(sit-stand)=(L-0.4) x body mass x g x 10/T(sit-stand). The cross-sectional area of the quadriceps femoris muscle (CSA(KE)) and the maximal voluntary isometric knee extension force (F(KE)) were measured using MRI and a static myometer, respectively. There was no significant correlation between T(sit-stand) and each of CSA(KE) and F(KE). On the other hand, the P(sit-stand) was highly correlated with CSA(KE) and F(KE), even after the influence of body mass and L was statistically eliminated. These results indicate that P(sit-stand), derived from three variables of body mass, leg length, and time taken for a sit-to-stand test, can be a useful index to assess the force-generating capacity of the knee extensor muscles of elderly individuals.
authors.affiliation: Graduate School of Sport Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama 359-1192, Japan. pacific-t1981@akane.waseda.jp
authors.forename: Yohei
authors.initials: Y
authors.lastname: Takai
authors.forename: Megumi
authors.initials: M
authors.lastname: Ohta
authors.forename: Ryota
authors.initials: R
authors.lastname: Akagi
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kanehisa
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kawakami
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Fukunaga
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D007717:Knee / Q000502:physiology*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000502:physiology*; D013997:Time Factors