%0 Journal Article %T Evaluations of neuromuscular dynamics of hyperactive reflexes poststroke %A Jie Liu %A BS %A Dali Xu %A PhD %A Yupeng Ren %A MS %A Li-Qun Zhang %A PhD %J Journal of Rehabilitation Research and Development %D 2011 %I Rehabilitation Research and Development Service, Department of Veterans Affairs %X Tendon reflexes are widely used in clinics to conveniently evaluate various neurological disorders. This study characterized neuromuscular dynamics of tendon reflexes at the elbow with multiple quantitative measures in both patients with stroke and nondisabled controls. We employed a handheld instrumented hammer to tap the triceps muscle tendon at various elbow flexion angles and measured the tapping force, triceps electromyography, and elbow extension torque to characterize neuromuscular dynamics of tendon reflexes quantitatively in terms of the tendon reflex gain, contraction rate, half relaxation rate, reflex loop delay, and reflex threshold in tapping force. We found that the tendon reflex gain, contraction rate, and half relaxation rate were significantly higher while the reflex threshold was significantly lower across different joint angles in patients with stroke than in nondisabled controls (p < 0.05), indicating hyperactive neurological state and muscle contraction dynamics poststroke. This study presents a convenient and quantitative method to evaluate reflex excitability and muscle contraction dynamics. %K contraction rate %K half relaxation rate %K neurological disorder %K reflex gain %K reflex loop delay %K reflex threshold %K rehabilitation %K spasticity %K stroke %K tendon reflex %U http://www.rehab.research.va.gov/jour/11/485/pdf/doaj/liu485.pdf