MULTI-PLANAR ANALYSIS OF THE TRADITIONAL BACK SQUAT AND SMITH MACHINE BACK SQUAT

This study evaluated the kinetic differences between the traditional back squat (T-BS) and Smith machine back squat (SM-BS) performed at a variety of loads. Ten subjects were tested in six conditions including the T-BS and SM-BS each performed at 50%, 80%, and 100% of the subject’s five repetition maximum load on a force platform. The analysis of vertical ground reaction forces (GRF) revealed significant main effects for exercise load (p ≤ 0.001) but not for squat condition or the interaction of load and squat condition (p \u3e 0.05). The analysis of sagittal plane GRF revealed significant main effects for exercise load (p ≤ 0.05), squat condition (p ≤ 0.001), and the interaction between load and condition (p ≤ 0.05). The analysis of frontal plane GRF revealed no main effects (p \u3e 0.05). The SM-BS offers the user a resistance stimuli in the sagittal plane against which the exerciser can produce greater sagittal force

KINETIC AND SUBJECTIVE ANALYSIS OF KNEE ROLLERS, HANDS FREE CRUTCH, AND CONVENTIONAL CRUTCHES

This study assessed the kinetic demands of ambulatory assistance devices and the subject’s perceptions of each. Twelve subjects used a knee roller (KR), a hands free crutch (HFC), and conventional axillary crutches (CC), while walking over a force platform. Ground reaction forces (GRF) were obtained for each device for the unaffected and the affected limb. Significant differences in GRF for each device were found for each limb (p ≤ 0.001). No gender interaction was found (p \u3e 0.05). The GRF of the un-affected limb was highest for the CC and lowest for the KR (p ≤ 0.05). The GRF of the affected limb was higher for the KR compared to the HFC (p =.045). For the unaffected limb, the CC produced 45% more kinetic demand than the KR, and 11% more than the HFC. However, the qualitative analysis suggested that the CC and KR were favored over the HFC

GENDER ANALYSIS OF HIP ABDUCTOR AND ADDUCTOR FORCE RATIOS

The strength of hip abductors (ABD) and adductors (ADD) have been implicated in athletic injuries. This study assessed ABD:ADD in a variety of testing conditions and sought to assess gender differences therein. Fifteen men and fifteen women participated in this study. Subjects performed maximum voluntary isometric muscle actions for hip ABD and ADD against a portable force plate which was manually applied statically by research personal. Subjects were tested in four conditions included supine, supine with hip flexion, seated with knee extension, and standing. Results revealed no significant main effects or gender interaction for testing position for ABD:ADD, ABD force, or ADD force (p ≤ 0.05). Results show that easy to use, valid, and reliable methods of assessing ABD:ADD exist, irrespective of testing position