For single pliometric (lengthening) contractions initiated from optimal fiber length (Lf), the most important factor determining the subsequent force deficit is the work input during the stretch. We tested the hypothesis that regardless of the initial length, the force deficit is primarily a function of the work input. Extensor digitorum longus muscles of mice were maximally activated in situ a...

The activation of a muscle depends on the function that it is performing and on the architectural properties of that muscle; the two are inextricably linked. Activation conditions such as activation timing, duration and amplitude can be varied throughout a cyclical movement (such as locomotion) and the length change of the whole muscle tendon unit (MTU) can also be varied. Architecturally, musc...

Relaxed striated muscle cells exhibit mechanical fatigue when exposed to repeated stretch and release cycles. To understand the molecular basis of such mechanical fatigue, single molecules of the giant filamentous protein titin, which is the main determinant of sarcomeric elasticity, were repetitively stretched and released while their force response was characterized with optical tweezers. Dur...

The ability of rabbit trachealis to undergo plastic adaptation to chronic shortening or lengthening was assessed by setting the muscle preparations at three lengths for 24 h in relaxed state: a reference length in which applied force was approximately 1-2% of maximal active force (P(o)) and lengths considerably shorter and longer than the reference. Passive and active length-tension (L-T) curve...

This study provides the first in vivo measures of the passive length-tension properties of relaxed human muscle fascicles and their tendons. A new method was used to derive passive length-tension properties of human gastrocnemius muscle-tendon units from measures of ankle stiffness obtained at a range of knee angles. Passive length-tension curves of the muscle-tendon unit were then combined wit...

purpose: this study aimed to assess the effect of boston brace on trunk muscles length as well as lower limbs and trunk range of motion in patients with idiopathic scoliosis. methods: five patients with idiopathic scoliosis with c shape curve and mean (sd) age, height, and weight of respectively 12.61(1.16) years, 1.53(0.08) m, and 35.6(6.1) kg participated in this study. spatiotemporal paramet...

In this study, the malondialdehyde (MDA) levels in the muscle, liver and kidney tissues and the antioxidant vitamin (A, C, E) levels in the muscle tissue of juvenile rainbow trout were investigated under different oxygen levels (3.5 mg O2/l, 4.5 mg O2/l and 7 mg O2/l) at the end of the 8 hour trial. Fish (initial weight and length, 30.19±2.2 g and 13.15±0.22 cm, respectively) were distributed i...