Activity of Trunk and Lower Extremity Musculature: Comparison Between Parallel Back Squats and Belt Squats.
Level 3 - non-randomized controlled study
Within-subject comparative biomechanical study with non-randomized repeated measures.
PubMed 32269663 · doi:10.2478/hukin-2019-0126
What was done
Ten resistance-trained participants (9 males, 1 female; mean age 29.3 ± 4.9 years, body mass 96.2 ± 17.8 kg) performed three sets of 5 repetitions of back squats and belt squats loaded to 100% bodyweight. Peak and integrated surface electromyographic (sEMG) activity across trunk, gluteal, and lower extremity musculature were normalized to maximum voluntary isometric contraction and compared using a one-way ANOVA.
What was found
Belt squatting significantly reduced muscle activation compared to back squatting: - Lumbar erectors: 45.4% decrease in impulse, 52.0% decrease in peak. - Gluteus maximus: 35.2% decrease in impulse, 32.1% decrease in peak. - Gluteus medius: 54.1% decrease in impulse, 55.2% decrease in peak. - Rectus abdominis: 44.3% decrease in impulse, 31.1% decrease in peak. - External obliques: 45.8% decrease in impulse, 53.7% decrease in peak. Activation of the quadriceps, hamstrings, and plantar flexors did not differ significantly between conditions.
Why it matters
Belt squats allow comparable quad and hamstring recruitment to back squats while roughly halving the demand on lumbar extensors and trunk stabilizers, making them a practical alternative when spinal loading must be minimized.
Limits
Small sample size (n = 10) with unbalanced sex distribution (9 men, 1 woman). Loading was normalized to bodyweight rather than a percentage of 1RM for each specific movement. Acute surface EMG measures recruitment rather than longitudinal hypertrophy or strength outcomes.
Cited by
- supports Belt squats eliminate axial loading on the spine compared to traditional barbell squats.