Mixed
Performing squats to depths greater than 90 degrees of knee flexion does not increase ACL or PCL injury risk and may enhance joint stability through increased soft tissue constraint, while maximizing quadriceps and gluteus maximus activation.
If you have healthy knees, squatting deep (past parallel) is safe and likely better for your ligaments than stopping at 90 degrees. It also recruits more muscle. If you have specific knee pain or cartilage issues, consult a professional to determine your safe depth.
These concerns [injury to soft tissue structures in the knee during high flexion], however, appear largely unwarranted. Although it is true that shear forces tend to increase with increasing knee angles, forces on the ACL and PCL actually decrease at high flexion... knee structures are highly constrained at angles greater than 120, resulting in much less anterior and posterior tibial translation... The upshot is better stability and greater tolerance to load.
Why this rating
Based on a review of multiple biomechanical studies (Li et al., Toutoungi et al., Escamilla) with consistent findings on ligament forces.
Source
Squatting Kinematics and Kinetics and Their Application to Exercise Performance
Brad J. Schöenfeld · The Journal of Strength and Conditioning Research · 2010
DOI 10.1519/jsc.0b013e3181bac2d7
More from this paper
- Front squats produce significantly lower maximal joint compressive forces at the knee and reduced lumbar stress compared to back squats, while maintaining similar quadriceps and hamstring activity.Good
- Maintaining a neutral spine and upright trunk posture during squats minimizes compressive and shear forces on the lumbar spine, whereas forward lean or lumbar flexion significantly increases injury risk.Good
Related findings · Mixed
- Bariatric surgery (VSG and RYGB) is the most effective and sustainable treatment for obesity, producing marked and sustained weight loss that non-surgical interventions cannot match.Strong
- Severely protein-deficient diets (2–3% energy) induce lean body mass loss and metabolic imbalance, whereas adequate protein intake (0.66 g/kg/d minimum) is a prerequisite for maintaining muscle, bone, and physiological function.Strong
- For patients with Class III obesity (BMI >39.9 kg/m2), metabolic bariatric surgery (MBS) is significantly more effective than any currently approved medication, with BilioPancreatic Diversion (BPD) showing the highest estimated weight loss.Strong
This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →