Performance characteristics of the Kin-Com dynamometer.
OBJECTIVE
The purpose of this study was to assess the performance characteristics of a Kin-Com dynamometer (model #500-11) under controlled conditions.


METHODS
Comparisons were made between measurements of force, angle, and velocity obtained from the Kin-Com and measurements acquired from an external recording system of known weights, angles, and user-set velocities. The strength of the linear relationships between measurements obtained with the different recording systems was analyzed using a coefficient of determination (r2). An intraclass correlation coefficient (ICC[2,1]) was used to examine the reliability of the force, angle, and velocity measurements obtained with each recording system on 2 different days.


RESULTS
In all conditions, the coefficient of determination for the force, angle, and velocity comparisons was above .99. The ICC for between-day comparisons for all force, angle, and velocity measurements was above .99.


CONCLUSIONS
Our results indicate that the static measurements of force and angle that are necessary for use in the gravity-correction procedure and isometric testing are accurate and replicable between days. The Kin-Com dynamometer's control system regulating lever arm velocity is also accurate and replicable under a no-load condition. It was ascertained during the velocity testing that the use of any acceleration and deceleration mode other than "high" resulted in a loss of excursion of the lever arm.
Department of Physical Therapy, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298.
T P
TP
Mayhew
J M
JM
Rothstein
S D
SD
Finucane
R L
RL
Lamb
D000054:Acceleration; D015982:Bias; D001696:Biomechanical Phenomena; D002138:Calibration; D003654:Deceleration; D003936:Diagnosis, Computer-Assisted / Q000295:instrumentation*; D004568:Electrodiagnosis / Q000295:instrumentation*; D004867:Equipment Design; D006112:Gravitation; D006801:Humans; D016014:Linear Models; D008422:Materials Testing; D009119:Muscle Contraction / Q000502:physiology; D026741:Physical Therapy Modalities / Q000295:instrumentation*; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D016474:Weight-Bearing