HYPOTHESIS Loss of range of motion after injury or surgery of the elbow is a common complication. We hypothesized that an orthosis that used progressive stretch and stress relaxation principles would improve elbow range of motion. METHODS This study evaluated the result of a patient-directed, bidirectional orthosis that uses static progressive stretch and stress relaxation principles to impro...

OBJECTIVE Analyze in vitro the mechanical response of bovine calcaneus tendons subjected to static stretching in three different intervals (15, 30, 45 s). METHODS Six groups of bovine calcaneus tendons (n=10) were formed according to the static stretching protocol: three different intervals (15, 30, 45 s) and initial stretching percentage (2.5% and 3.5%). The control group (n=10) did not perf...

During animal development and homeostasis, the structure of tissues, including muscles, blood vessels, and connective tissues, adapts to mechanical strains in the extracellular matrix (ECM). These strains originate from the differential growth of tissues or forces due to muscle contraction or gravity. Here we show using a computational model that by amplifying local strain cues, active cell con...

Mention glutamate secretion to most physiologists, even neuroscientists, and they'll think only of excitatory synaptic neurotransmission in the central nervous system. Although by far its best known function, evidence from last 15 years shows it is also vital for controlling peripheral mechanosensory terminal responsiveness, via autogenic excitation. In an article appearing a previous issue The...

CONTEXT Greater musculotendinous stiffness may enhance spinal stretch reflex sensitivity by improving mechanical coupling of the muscle spindle and the stretch stimulus. This heightened sensitivity would correspond with a shorter latency and higher-amplitude reflex response, potentially enhancing joint stability. OBJECTIVE To compare spinal stretch reflex latency and amplitude across groups t...

KEY POINTS In tonic, isometric, plantarflexion contractions, physiological tremor increases as the ankle joint becomes plantarflexed. Modulation of physiological tremor as a function of muscle stretch differs from that of the stretch reflex amplitude. Amplitude of physiological tremor may be altered as a function of reflex pathway gains. Healthy humans likely increase their γ-static fusimotor d...

A linear lumped-parameter mechanical model of the muscle spindle is presented. It is shown that the model simulation exhibits the spindle behavior in most aspects of transient ramp-stretch performance. The requirements that such a model places on the mechanisms of fusimotor control are discussed. Then the efficacy of static γ and dynamic γ stimulation on primary ending output and secondary endi...