title: Knee joint angular velocities and accelerations during the patellar tendon jerk.
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.
authors.affiliation: Health 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
authors.forename: Maria K
authors.initials: MK
authors.lastname: Lebiedowska
authors.forename: Siddhartha
authors.initials: S
authors.lastname: Sikdar
authors.forename: Avinash
authors.initials: A
authors.lastname: Eranki
authors.forename: Lindsay
authors.initials: L
authors.lastname: Garmirian
mesh_terms: D000054:Acceleration; D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology; D004576:Electromyography; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000502:physiology; D017847:Patellar Ligament / Q000000981:diagnostic imaging / Q000502:physiology*; D010865:Pilot Projects; D012026:Reflex, Stretch / Q000502:physiology*; D014463:Ultrasonography