| This investigation determined if the angle of pelvic inclination, viewed in the sagittal plane, affects the neuromuscular activation strategy of selected trunk and lower extremity muscles in asymptomatic, physically active females, during a well-controlled squat maneuver. Two groups of physically active females (x age = 22.16 ± 3.44yrs., x ht. = 164.63 ± 7.02 cm., x wt.= 64.07 ± 13.25 kg.) selected by sagittal view pelvic inclination were evaluated. The neutral pelvic position group (n = 7) was defined as those with pelvic inclination from 0–5 degrees (x = 4.11 ± 1.09 degrees). The anterior inclination position group (n = 15) was defined as those with pelvic inclination ≥10 degrees (x = 15.88 ± 2.90 degrees). The EMG data were analyzed using an ANOVA, assessing muscle onset latency reported in milliseconds (ms) and EMG amplitude values reported as mean normalized root means square in percent (%) for each of the six muscles, rectus abdominis (RA), external oblique (EO), erector spinae (ES), gluteus maximus (GM), rectus femoris (RF) and biceps femoris (BF). Selected muscle amplitude ratios were also evaluated using Student's t-test, to explore functional relationships between anterior and posterior muscle groups. No statistically significant differences were found for any of the variables, muscle onset latency, muscle amplitude or the ratio data suggesting that the position of the pelvis did not play a significant mechanical role in the neuromuscular recruitment of the trunk and lower extremity muscles. However, burst duration data indicated that most muscles were active during the entire squat maneuver suggesting that the task selection promoted a co-contraction behavior rather than the expected distinguishable bursting characteristics of a more demanding task. Clinicians should be cautious of discarding the practice of rehabilitating patients in the neutral pelvic position. Future research should repeat this study using a more demanding task. |
