Tetanic neuromuscular electrical stimulation (at 100 Hz) over ankle dorsiflexors and plantarflexors in persons with and without spinal cord injury can evoke contractions, which are considered spinal of origin, extra to those due to stimulating motor axons directly. Presently, we determined whether H-reflexes contribute to “extra” plantarflexion contractions, evoked in relaxed neurologically-int...

MEASUREMENT of the ankle reflex time by means of a kinemometer has been shown to be a useful aid in the clinical diagnosis of hypothyroidism (Abraham, Atkinson, and Roscoe, 1966). It is not known whether it will also serve as a screeing procedure for this disorder. In the Birmingham region a follow-up system has recently been initiated to effect the continued surveillance of thyrotoxic patients...

A parallel-cascade system identification technique was used to examine the intrinsic and reflex contributions to overall ankle stiffness in normal (control) and spastic spinal cord injured (SCI) subjects as a function of voluntary contraction level. Intrinsic dynamics were modeled as a linear, 2nd-order system relating intrinsic torque to joint position. Reflex dynamics were described by a line...

An obstacle contacting the dorsal surface of a cat's hind foot during the swing phase of locomotion evokes a reflex (the stumbling corrective reaction) that lifts the foot and extends the ankle to avoid falling. We show that the same sequence of ipsilateral hindlimb motoneuron activity can be evoked in decerebrate cats during fictive locomotion. As recorded in the peripheral nerves, twice thres...

Running title: Stumbling correction reflexes during fictive locomotion. SUMMARY An obstacle contacting the dorsal surface of a cat's hind foot during the swing phase of locomotion evokes a reflex (the stumbling corrective reaction) that lifts the foot and extends the ankle to avoid falling. We show that the same sequence of ipsilateral hindlimb motoneuron activity can be evoked in decerebrate c...

Ankle inversion sprains are the most frequent acute musculoskeletal injuries occurring in physical activity. Interventions that retrain muscle coordination have helped rehabilitate injured ankles, but it is unclear which muscle coordination strategies, if any, can prevent ankle sprains. The purpose of this study was to determine whether coordinated activity of the ankle muscles could prevent ex...

The identification of a dynamic, nonlinear model of human ankle stiffness is considered in a minimum mean squared error framework. The model consists of two parallel pathways, one representing the intrinsic dynamics, the other representing the reflex contribution to the stiffness. The model is shown to be linear in all of its parameters, except for those used to describe a single static nonline...

Using the ankle musculature, subjects balanced a large inverted pendulum. The equilibrium of the pendulum is unstable and quasi-regular sway was observed like that in quiet standing. Two main questions were addressed. Can subjects systematically change sway size in response to instruction and availability of visual feedback? If so, do subjects decrease sway size by increasing ankle impedance or...

A patient suffering from acute smoke inhalation also had a long medical history that included reflex sympathetic dystrophy syndrome of the left foot and ankle. The entire foot and ankle were tender and cool to palpation; range of motion was severely reduced. She was referred for hyperbaric oxygen therapy, and 15 min into the the first treatment (46 min at 60 fsw) she reported a lessening of the...

Moon, of Dundee, in November 1893. He was then reported to be childish in manner, usually absolutely taciturn, although cheerful and talkative at times ; patellar reflex absent; loss of control of bladder and rectum ; walking and standing steadily ; occasionally sliding off his chair on to the floor with a thump, and remaining stiff; eyes sometimes open, sometimes closed; no spasm. I found him ...