Validity of lower extremity strength and power utilizing a new closed chain dynamometer.
OBJECTIVE
The purpose of this study was to compare selected variables measured on a traditional isokinetic dynamometer (Cybex II) with a new lower extremity, closed chain dynamometer (Omnikinetic, OmK).


METHODS
Twelve subjects (6 male, 6 female, age = 28+/-5 yr, mean +/- SD) performed Cybex II knee flexion and extension at 1.05, 3.14, and 5.23 rad x s(-1). A maximal effort of 10 repetitions of lower extremity concentric extension and eccentric flexion at 36% of subject's 1-RM was performed on the OmK. Crank power and joint (ankle, knee, and hip) kinetics were recorded as a mean of 10 repetitions.


RESULTS
t-Tests revealed right versus left leg differences (P < 0.05) for Cybex II peak torque flexion at 5.23 rad x s(-1), and OmK knee and hip peak power and hip root mean square power (RMS) power. Cybex peak knee torques were related (Pearson r values 0.78-0.92, P < 0.01) to OmK peak knee torques. Cybex average power was related to OmK knee power (Pearson r values 0.71-0.96, P < 0.01) and OmK crank power (r = 0.62-0.94, P < .01). Correlations tended to be stronger comparing the OmK with the fastest (5.23 rad x s(-1)) Cybex II speed.


CONCLUSIONS
These results suggest that the OmK knee and crank kinetic data are comparable to Cybex It isokinetic dynamometry. The ability to evaluate lower extremity joint exercise at a subject's maximal movement speed, in addition to the use of a closed-chain, multi-joint motion, may allow for the OmK to provide a more global evaluation of lower extremity kinetics during seated concentric-extension, eccentric-flexion exercise.
Dolny
D G
DG
Human Performance Laboratory, University of Idaho, Moscow 83844, USA. ddolny@uidaho.edu
Collins
M G
MG
Wilson
T
T
Germann
M L
ML
Davis
H P
HP
D000328:Adult; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007700:Kinetics; D007866:Leg / Q000502:physiology*; D008297:Male; D009068:Movement; D015203:Reproducibility of Results; D012984:Software; D013177:Sports; D013718:Tensile Strength; D019415:Torque