Stature and Flexibility Variables as Discriminators of Foot Contact During the Squat

[3XL]

The Journal of Strength and Conditioning Research: Vol. 2, No. 2, pp. 24–26.


Stature and Flexibility Variables as Discriminators of Foot Contact During the Squat Exercise
Andrew C. Fry, Terry J. Housh, Roger A. Hughes, and Thora Eyford


Center for Youth Fitness and Sports Research, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0138




ABSTRACT
A problem for some novice trainees in a strength program is the inability to maintain complete foot contact with the ground during the parallel squat weight training exercise. The purpose of this study was to determine the relative contribution of selected physical characteristics in discriminating between subjects who were able to maintain complete foot contact with the floor during this exercise and those who could not. Fifty males ( age = 21.1 * 2.67 years) in beginning weight training classes were measured for height (HT), torso length (TL), femur length (FL), mean of right and left ankle dorsi-flexion (AF), and sit and reach flexibility (SR). Each subject performed three parallel squats with a 20 kg barbell across the top of the trapezius, and with feet shoulder-width apart. Those able to maintain complete foot contact with the ground were classified as Group 1 (n = 42) and all others as Group 2 (n = 8). A correlation matrix revealed that none of the five measured variables shared more than 18 percent common zero-order variance. A full-model multiple discriminant analysis correctly classified 94 percent of the subjects. The relative contribution of each variable to the explained variance from the discriminant function included HT (36.0 percent), TL (33.0 percent), SR (9.3 percent), FL (8.8 percent), and AF (6.9 percent).

These data indicate that physical stature and body segment dimensions are more potent discriminators than flexibility measures for the ability to maintain complete foot contact during the parallel squat exercise. Furthermore, tall subjects with relatively short torsos appear to have greater difficulty maintaining foot contact during this exercise than do shorter subjects with relatively long torsos

[3XL]

The Journal of Strength and Conditioning Research: Vol. 5, No. 2, pp. 77–81.


Stature Variables as Discriminators of Foot Contact during the Squat Exercise in Untrained Females
Andrew C. Fry and William J. Kraemer


Center for Sports Medicine, Pennsylvania State University, University Park, PA 16802
Khalid W. Bibi


Department of Sport, Leisure and Exercise Sciences, University of Connecticut, Storrs, CT 06269
Thora Eyford


Center for Youth Fitness and Sports Research, University of Nebraska-Lincoln, Lincoln, NE 68588-0138




ABSTRACT
Fry, A.C., Kraemer, W.J., Bibi, K.W. and T. Eyford. Stature variables as discriminators of foot contact during the squat exercise in untrained females. J. Appl. Sport Sci. Research. 5(2):77–81. 1991.—Previous research indicates that stature variables (height [HT], torso length [TL], femur length [FL] are potent discriminators of complete foot contact with the ground during the parallel squat exercise for males in a beginning weight training program. The purpose of this study was to determine if the same variables are also potent discriminators for untrained females. Females in beginning weight training classes (n = 26, age = 20.8 * 2.9 years) were measured for the three stature variables. After two weeks of introductory instruction and familiarization with the exercise, each subject performed three parallel squats with a 20-kg barbell across the top of the trapezius, and with feet shoulder width apart. Those able to maintain complete foot contact with the ground were classified as successful (n = 19), and all others as unsuccessful (n = 7). A correlation matrix revealed that none of the three stature variables shared more than 53 percent common zero-order variance (r2). A full-model multiple discriminant analysis correctly classified only 77 percent of the subjects (N.S., p > 0.05). The relative contribution of each variable to the explained variance from the discriminant function include FL (49.0 percent), TL (29.8 percent) and HT (0.8 percent).

These data indicated that stature variables are equally potent discriminators of proper foot contact during the squat exercise for females as for previously investigated males, but that the most potent discriminator for females (femur length) was different than that previously found for males (height). Furthermore, 20.4 percent of the variance was not explained, indicating that factors other than HT, TL or FL contribute to improper foot contact during the squat exercise with untrained females