Affiliations: [a] Cherokee High School, Marlton, NJ 08053, USA | [b] Division of Graduate Athletic Training in the
Department of Clinical Sciences, College of Allied Health Professions at the
University of Kentucky, Lexington, KY 40536-0003, USA | [c] Department of Kinesiology and Leisure Sciences at the
University of Hawaii at Manoa, Honolulu, HI~96822, USA
Note: [] Director -- Division of Graduate Athletic Training, CAHP
Building, Room 205, 121 Washington Avenue, University of Kentucky, Lexington,
KY 40536-0003, USA. Tel.: +1 606 323 1100 ext. 267; Fax: +1 606 257 1816;
E-mail: [email protected]
Abstract: The purpose of this study was to determine the effect of visual
feedback and verbal encouragement on concentric peak torque of the quadriceps
and hamstrings muscles of males and females at an isokinetic velocity of
60~deg/s. All testing was performed on the Biodex B-2000 isokinetic dynamometer
in three sessions, separated by 7 to 14 days. Fifteen males and 15 females (age
= 25.4 \pm 2.4 yrs, wt = 76.6 \pm 16.5
kg, ht = 173.61 \pm 9.5 cm) were tested under the following
conditions: (a) visual feedback, (b) verbal encouragement, (c) combined visual
feedback and verbal encouragement, and (d) no feedback (control). Testing order
was counterbalanced to control for possible learning effects. Two separate 2
\times 4 repeated measure analyses of variance (ANOVA) were
used to examine the difference among test conditions. Examination of quadriceps
force production revealed that subjects generated greater peak torque when
visual feedback was provided than when verbal encouragement or no feedback were
provided. Similarly, quadriceps force production was greater when combined
visual feedback and verbal encouragement was provided than when verbal
encouragement or no feedback were provided (p<0.05). Examination of
hamstrings force production revealed that subjects generated greater peak
torque when combined visual feedback and verbal encouragement was provided than
when verbal encouragement, and no feedback were provided. Additionally,
hamstrings force production was greater when visual feedback was provided than
when no feedback was provided (p<0.05). These results indicate that the use
of visual and combined visual and verbal feedback increased quadriceps and
hamstrings force production when compared to the control condition where no
feedback was provided.
