The pendulum test for evaluating spasticity of the elbow joint.
OBJECTIVE
To develop a modification of the pendulum test to allow evaluation of elbow spasticity.


METHODS
The main difficulties of directly applying the conventional pendulum test to the elbow were the small inertia of the forearm and the uncomfortable posture. We designed an experimental apparatus similar to a clock pendulum and developed an elbow biomechanic model to measure objectively spasticity of the elbow joint. The model consisted of linear stiffness and damping and gravity contribution.


METHODS
A referral medical center in Taiwan.


METHODS
Eleven stable stroke patients and 11 able-bodied subjects.


METHODS
A custom-designed accessory apparatus to facilitate the pendulum test in elbow joints.


METHODS
By using an optimization technique, we estimated parameters of the proposed elbow biomechanic model as the candidate indicators of spasticity.


RESULTS
The stiffness constant remained relatively consistent in all groups. Both the damping coefficient and damping ratio increased in the affected side of stroke patients and tended to increase with the severity of spasticity. Damping ratio had marginally better differentiation capability than the damping coefficient.


CONCLUSIONS
The damping ratio derived from the proposed model differentiated spasticity from normotonus and increased as spasticity increased.
Lin
Chou-Ching
CC
Department of Neurology, University Hospital, Tainan, Taiwan. cxl45@mail.ncku.edu.tw
Ju
Ming-Shaung
MS
Lin
Chun-Wang
CW
D000328:Adult; D000368:Aged; D000465:Algorithms; D001696:Biomechanical Phenomena; D004551:Elbow Joint / Q000503:physiopathology*; D004576:Electromyography; D006801:Humans; D008875:Middle Aged; D009128:Muscle Spasticity / Q000175:diagnosis* / Q000503:physiopathology / Q000534:rehabilitation; D000071939:Stroke Rehabilitation