A Biomechanical Comparison Between the Safety-Squat Bar and Traditional Barbell Back Squat

The primary objectives for this investigation were to compare the kinematic and kinetic differences between performing a parallel back squat using a traditional barbell (TB) or a safety-squat bar (SSB). Fifteen healthy, recreationally trained male subjects (23 + 4 years of age) performed the back squat with a TB and an SSB at 85% of their respective 1 repetition maximum with each barbell while instrumented for biomechanical analysis. Standard inverse dynamics techniques were used to determine joint kinematic and kinetic measures. A 2 x 3 (exercise x joint) factorial analysis of variance with repeated measures was used to determine the kinetic and kinematic differences between the squats while using the different barbells. Fisher's least significant difference post hoc comparisons showed that the TB resulted in significantly greater maximum hip flexion angle (129.33 +/- 11.8 degrees vs. 122.11 +/- 12.1 degrees; p < 0.001; d = 1.80), peak hip net joint extensor torque (2.54 +/- 0.4 Nm<middle dot>kg-1 vs. 2.40 +/- 0.4 Nm<middle dot>kg-1; p = 0.001; d = 1.10), hip net extensor torque mechanical energy expenditure (MEE; 2.81 +/- 0.5 Nm<middle dot>kg-1 vs. 2.58 +/- 0.6 Nm<middle dot>kg-1; p = 0.002; d = 0.97), and ankle net joint plantar flexor torque MEE (0.32 +/- 0.09 J<middle dot>kg-1 vs. 0.28 +/- 0.06 J<middle dot>kg-1; p = 0.029; d = 0.63), while also lifting significantly (123.17 +/- 20.8 kg vs. 117.17 +/- 20.8 kg; p = 0.005; d = 0.858) more weight than the SSB. The SSB resulted in significantly higher maximum knee flexion angles (116.82 +/- 5.8 degrees vs. 115.65 +/- 5.6 degrees; p = 0.011; d = 0.75) than the TB, with no significant difference in kinetics at the knee. The TB may be preferred to the SSB for developing the hip extensors and lifting higher maximum loads. The SSB may be advantageous in situations where a more upright posture or a lower load is preferred while creating a similar demand for the knee joint.