Fig. 4.
Architectural gear ratio (AGR) during shortening and lengthening contractions across a range of contraction forces. Gear ratio is quantified as the ratio of muscle–tendon unit (MTU) velocity to muscle fascicle velocity measured during a period of constant force. (A) During shortening contractions, AGR decreases with increasing force. Data are fitted with a least-squares linear fit (AGR=–0.91P+2.01, where P is force; R2=0.69, P<0.001). (B) During lengthening contractions, AGR decreases with increasing force. Data are fitted with a least-squares linear fit (AGR=−2.97P+7.23; R2=0.61, P<0.001). Data are pooled from seven muscles and shown as means ± s.e.m. Po, maximum isometric force.