# Comparative Analysis of Performance in the High-Bar vs. Low-Bar Squat
## 1 Introduction
The latter, in turn, has two variations: the high bar (the bar is either centered across the shoulders just below the spinous process of the C7 vertebra), or the low bar (the bar is placed on the back across the spine of the scapula) [22]. Several studies have confirmed that a variation in where the bar is placed modifies the muscles involved [22; 23]. Also, lifters adopt different postural control strategies based on the intensity of the load while performing both techniques [24]. The high bar squat permits a greater flexion of the knee, lesser flexion of the hip, a more upright torso, and a deeper squat. In the low-bar squat, there is more hip flexion and therefore more forward lean [16; 25]. In terms of muscular activation, the high bar squat consists of increased activity of the quadriceps muscle, while in the low-bar squat, greater muscle activity of the erector spinae, adductor, and gluteal muscles can be observed [13]. Furthermore, [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], and [PERSON] [23] conclude that there are significant differences in the activation of the posterior muscle chain between the two squat techniques. The erector spinae, gluteus maximus, biceps femoris, rectus femoris, vastus lateralis, and vastus medialis muscles are more active during the eccentric phase of the low-bar squat than during the high-bar squat. In the case of the knee extensor muscles, the differences between the techniques are rather negligible. Finally, in both techniques, the most crucial muscles--the gluteus maximus and biceps femoris--show higher levels of activation in the low-bar squat. Since the differences in muscular activation are known, a question arises as to whether this translates to a difference in force and power production using one technique or another. This becomes an important factor in training athletes who use one technique more than the other. Among strength and power sports, powerlifting and weightlifting are the most widely practiced and popular, representing the two most common disciplines globally [26, 27]. For example, powerlifting is a strength sport that consists of three attempts at maximal weight on three lifts: squat, bench press, and deadlift [27]. In this sport, [PERSON] and [PERSON] [28] reported that the most used technique is the low-bar squat. On the other side, weightlifters primarily use the high-bar technique, as it more closely mimics the movements involved in their snatch and clean and jerk competitions [29]. As there are different characteristics between techniques, it is necessary to have specific references in terms of force and velocity values during the execution of this exercise, which can help adapt the velocity-based training program accurately and achieve optimal results. Another important question to be consider in this context is the difference in strength between genders. Sex-based differences can be appreciated in skeletal muscle fiber type composition and function [30]. Females have more of the slower Type I and -IIA fibers than males, which means a lower contractile velocity, an important factor during a squat. As we can see in a study performed by [PERSON], et al. [31], there are differences in muscle activity between men and women during the back squat, with the biceps femoris showing a greater activation in men. Biomechanically, we can appreciate differences when they perform the Overhead Squat and Single Leg Squat [32]. For example, males displayed the Overhead Squat with greater peak knee frontal plane projection angles, peak hip flexion, and peak trunk flexion angles. Therefore, the main objective of the present study was to compare the 1 Repetition Maximum (RM) performance (lifted load, mean propulsive velocity, and force) in the parallel squat exercise with the low-bar and high-bar techniques and to analyze the gender differences. A secondary objective was to analyze the differences in the force-velocity profile between the low and the high bar squat technique.