Gail F. Koshland

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Studies of multijoint arm movements have demonstrated that the nervous system anticipates and plans for the mechanical effects that arise from motion of the linked limb segments. The general rules by which the nervous system selects appropriate muscle activities and torques to best deal with these intersegmental effects are largely unknown. In order to(More)
We have used the phenomenon that speed increases with movement amplitude as a rehabilitation strategy. We tested the hypothesis that the generalized training of amplitude in the limb motor system may reduce bradykinesia and hypokinesia in the upper and lower limbs in subjects with Parkinson’s disease (PD) across disease severity (Stage I, n=6; Stage II,(More)
In a reaching movement, the wrist joint is subject to inertial effects from proximal joint motion. However, precise control of the wrist is important for reaching accuracy. Studies of three-joint arm movements report that the wrist joint moves little during point-to-point reaches, but muscle activities and kinetics have not yet been described across a range(More)
1. Hindlimb paw-shake responses were assessed before and after unilateral deafferentation (L3-S1) in chronic-spinal cats (n = 5), spinalized at the T12 level 1 yr earlier. Selected ankle flexor [tibialis anterior (TA)] and extensor [lateral gastrocnemius (LG)] and knee extensor [vastus lateralis (VL)] muscles were surgically implanted with chronic(More)
A fundamental issue in the neuromotor control of arm movements is whether the nervous system can use distinctly different muscle activity patterns to obtain similar kinematic outcomes. Although computer simulations have demonstrated several possible mechanical and torque solutions, there is little empirical evidence that the nervous system actually employs(More)
Intralimb coordination of the paw-shake response (PSR) was studied in five normal and eleven spinal adult cats. Representative extensor and flexor muscles that function at the hip, knee, and ankle joints were recorded, and in six spinal cats the kinematics of these joints were determined from high-speed cinefilm. The PSR was characterized uniquely by mixed(More)
Muscle activities and joint rotations were examined at the shoulder, elbow, and wrist joints for pointing movements to targets in the horizontal plane. In such movements, multiple arm configurations are possible for a given target location. Thus, starting from the same initial configuration and for the same target location in space, the joint excursions(More)
the changes in the electromyogram patterns of two antagonist muscles were studied when female subjects performed a motor task with and without an auditory rhythm. During the performance of the motor task without the rhythm, the subjects demonstrated a common and consistent personal tempo and a common electromyogram pattern. With the imposed timing of an(More)
Whether or not a lesion confined to the pyramidal tract produces spasticity in humans remains an unresolved controversy. We have studied a patient with an ischemic lesion of the right medullary pyramid, using objective measures of hyper-reflexia, spasticity, and weakness. Electromyographic activity (EMG) of the biceps muscles was recorded under the(More)
A unique feature of trunk muscles is that they can be activated to meet functional requirements for combined behaviors, including those related to posture and breathing. Trunk muscles therefore may have developed mechanisms for dealing with simultaneous inputs for different task requirements. This study was designed to test the hypothesis that a linear(More)