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Updated: Jun 2, 2026

An Inertial Measurement Unit Based Method to Estimate Hip and Knee Joint Kinematics in Team Sport Athletes on the Field
Published on: May 26, 2020
Knee joint angular velocities and accelerations during the patellar tendon jerk
Maria K Lebiedowska1, Siddhartha Sikdar, Avinash Eranki
1Health Effects Lab Division, Engineering and Control Technology Branch, National Institutes of Occupational Safety and Health, 1095 Willowdale Road MS 2027, Morgantown, WV 26505, USA. MLebiedowska@cdc.gov
Abstract:
Tendon jerk (TJ) is one of the most commonly used clinical tests in differential diagnosis of human motor disorders. There remains some ambiguity in the physiological interpretation of the test, especially with respect to its association to the functional status of patients. The TJ test inputs a non-physiological stimuli, but it is unclear to what degree the kinematics generated during the TJ test exceed the ranges that muscles encounter in activities of daily living (ADLs). The aim of our pilot study was to determine the range of angular knee kinematics (angular velocities and accelerations) corresponding to the muscle stretch elicited by TJ. We measured the longitudinal kinematics (velocities and accelerations) of the rectus femoris muscle in vivo using vector tissue Doppler imaging, an ultrasound-based method, and measured the angular kinematics of the knee in response to tendon taps with an electrogoniometer. We concluded that muscle longitudinal elongation accelerations elicited during the standard TJ test exceed angular accelerations (104.40-4534.20 rads⁻²) encountered in typical ADLs, but the velocities (0.82-6.21 rads⁻¹) elicited do not exceed those elicited by ADLs.
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