Biomechanical Differences Between the Bulgarian Split-Squat and Back Squat.

Area of Science:

• Biomechanics
• Exercise Physiology
• Sports Science

Background:

• The Bulgarian split squat (BSS) is a unilateral exercise, but its mechanical demands are not fully understood.
• Understanding joint-specific forces in the BSS compared to the bilateral back squat (BS) is crucial for exercise prescription.

Purpose of the Study:

• To compare the net joint moment impulse (NJMI), net joint work (NJW), peak net joint moment (NJM), and peak joint displacement of the ankle, knee, and hip between the BSS and BS.

Main Methods:

• Twenty resistance-trained males performed the BSS and BS at 35% and 70% of their 1-repetition maximum (1-RM), respectively.
• Kinematic and kinetic data were collected to analyze joint-specific mechanical demands.

Main Results:

• Both BSS and BS are hip-dominant exercises, with greater hip NJMI, NJW, and peak NJM compared to ankle and knee joints.
• The BSS demonstrated significantly less knee joint peak displacement compared to the BS.
• While the BSS showed lower knee NJMI and peak NJM than the ankle, the BS showed higher knee NJMI than the ankle.

Conclusions:

• The BSS and BS primarily load the hip joint.
• The BSS can be utilized to emphasize hip extension while minimizing knee joint stress, making it suitable for early-stage knee rehabilitation or addressing hip extension deficits.