Wretenberg et al (1) examined the differences between high-bar (used by Olympic lifters in training) and low-bar (used by powerlifters in training and competition) squatting
techniques. They examined differences in moments of force at the knee and hip joints and EMG activity of the vastus lateralis, rectus femoris, and biceps femoris. 8 Swedish national
class Olympic weightlifters and 6 Swedish national class powerlifters were used in the study. Weightlifters performed high-bar squats and powerlifters performed low-bar squats; each
group of lifters did not perform both types due to lack of skill in the technique that did not correspond with their particular sport. In both groups, 2 depths of squatting were examined:
parallel (posterior border of hamstring parallel with ground) and full (knees maximally flexed). All subjects lifted 65% of their all-time 1 RM. Motion analyses were performed
using a video camera, with skin markers placed at the trunk, hip, knee, ankle, and foot. Coordinates of the markers were established using a video position analyzer. Ground reaction
forces were measured using a Kistler force platform; vertical, anteroposterior, and lateral forces were measured during the ascent phase. Knee and hip joint moments were calculated using
a computer program and the data from the markers and the force platform. EMG activity was related to a static reference position to compare muscle activity of both types of squats. A
parametric t-test was used as the statistical analysis.
RESULTS: Powerlifters placed more load on the hip joint while weightlifters had an equal distribution of the load between the
knee joint and hip joint. maximum moments at the hip joint were significantly higher for the powerlifters as compared to the Olympic lifters (324 Nm deep and 309 Nm parallel vs. 230 Nm deep
and 216 Nm parallel). In contrast, maximum moments at the knee joint were significantly higher in the Olympic lifters (139 Nm deep and 92 Nm parallel for powerlifters vs. 191 Nm deep and 131
Nm parallel for Olympic lifters), despite the powerlifters having heavier bodyweights and lifting heavier loads. Patello-femoral compression force was significantly higher in the
weightlifters as compared to the powerlifters (4700 N vs. 3300 N). Powerlifters showed greater EMG in all measured muscles, although only the rectus femoris was found to reach statistical
IMPLICATIONS: Low-bar squatting techniques involve greater hip flexion and thus greater hip moments of force, while in the high-bar technique the load is more equally
distributed. the greater amount of hip flexion allows the lifter to balance the bar closer to the knee, reducing the moment arm between the knee and the weight. this reduces knee
moment forces and the patello-femoral compression force. This also results in greater reliance in the hip and back musculature, allowing the individual to lift more weight, which is crucial
An interesting outcome of this study was the slightly higher muscle activity found in the knee extensors of the powerlifters, despite the weightlifters having higher knee
moments. The authors' explanation was that the calculated moments were net moments; the muscular co-contraction of antagonistic muscle groups was not included in the calculations.
the greater hip extension needed during the ascent phase of the low-bar squat, along with the greater need for compensatory ankle plantar flexion, would result in greater hamstring and
gastrocnemius activity during the lift. The increase in activity of these muscles would result in an increased knee extensor co-contraction, resulting in high knee extensor EMG activity
despite low moments of force at the knee.
The higher knee moments of the high-bar squat indicates that a low-bar squat would be beneficial in knee rehabilitation situations. In contrast,
the higher hip moments of the low-bar squat indicates that a high-bar squat would be beneficial in hip rehabilitation situations.
1. Wretenberg, P., Y. Feng, and U.P.
Arborelius. High- and low-bar squatting techniques during weight-training. Med. Sci. Sports Exerc. 28(2):218-224. 1996.