Abstract des Autors

In order to compare kinematic variables during the front (FS), high bar (HBS), and low bar (LBS squats, 6 weight trained males (X+/-SD; age=24.8+/-7.2 yr, hgt.=181.5+/-9.7 cm, body wgt.=96.5+/-16.6 kg) performed 3 repetitions at 50% of 1 RM for each lift, and were videotaped perpendicular to the sagittal plane. A rigid body five link model was used with either the barbell center of mass (COM), or the 7th cervical vertebrae (C7) acting as the terminus of the trunk segment. Performances were analyzed with the Peak 2-D Motion Measurement System. Kinematic characteristics at the lowest position of the squat included shank and trunk angles relative to horizontal, and knee internal angles. A repeated measures ANOVA with a Tukey LSD post-hoc test was used for statistical analysis. No differences were observed between squat types for shank angles, but knee internal angles for the FS (60.0ø+/-11.8ø) were significantly less (p<0.05) than for the LBS (68.0ø+/-14.0ø). During the FS, the trunk segment angle using The C7 terminus (63.5ø+/-4.2ø) was significantly greater (p<0.01) than the trunk angle using the barbell COM (53.4ø+/-5.1ø). Additionally, using the C7 terminus, the trunk segment angle for the FS (63.6ø+/-4.2ø) was significantly greater (p<0.01) than for the HBS (46.3ø+/-4.8ø) or the LBS (40.7ø+/-5.8ø). However, when using the barbell COM terminus, the trunk segment angle for the FS (53.4ø+/-5.1ø) was significantly greater (p<0.01) than only the LBS (42.5ø+/-5.9ø). Using the barbell COM as the terminus of the trunk segment resulted in considerable kinematic error. This data clearly illustrates the kinematic differences between several commonly used barbell squat variations, as well as the importance of properly identifying the trunk body segment. Verf.-Referat