Squats are great. Lower back pain is not so great. Lower back pain triggered by squats is something I see much too regularly. With the increased popularity of high intensity training, which has great health and fitness benefits, the prevalence of low back pain from squatting has increased. It is not high intensity training or squats to blame, rather a lack of attention to technique and the factors that can put your lower back at risk. 

It is the lumbar discs that most commonly become irritated, triggering muscle spasm in the back and hips as a protective response. How do these discs become irritated? We'll get back to this. First, think about the curvature in your lower back when you stand upright. If there's a mirror close by stand side on to it and have a look at your lower back posture. It should curve in - otherwise known as a lumbar lordosis. The extent of the curve is variable amongst individuals, whatever yours is like this is your 'neutral' curve for your lumbar spine.

Maintaining this neutral curve when performing a squat is the most important thing to prevent back injuries. If we lose it by flexing or rounding through our lumbar spine the load on the lumbar spine increases and as a result there is increased compression of the lumbar discs. It is the deepest or 'turning point' of the squat (transitioning from a downward to upward motion) that we are most likely to flex, ruining our nice neutral lumbar spine.

Factors contributing to the spine flexing include:

• Deeper the squat = higher the chance of flexing
• Restricting the knees from moving past the toes increases forward lean of your trunk and therefore flexion through the lower back.
• Higher loads or weights = increased chance of flexing.
• Squatting near fatigue results in an increased risk of flexing. 

It is interesting to note that due to structural differences, females are more at risk of lower back injury with squats. 

Please do not give up on the squat - I believe the benefits far outweigh the risks. Rather, be aware of good technique and implement this in to your training. So the optimal squat technique.... Fortunately for me these two S & C gurus, Paul Comfort and Peter Kasim, have digested the literature on squats and come up with these four key steps:

1. Wide stance - at least shoulder width
2. Natural foot position
3. Unrestricted movement of the knees
4. full depth while the lordotic curvature of the lumbar spine is maintained

With lower back injury prevention in mind some additional tips from me:

• Only squat as deep as you can maintain a neutral spine position 
• Perform a lumbar extension manoeuvre at the turning/deepest point of the squat to help maintain lumbar lordotic curve
• If squatting deep don't overload it. More weight = more likely to lose the curve.
• Be extra aware of your technique when fatigued - if you're too fatigued to maintain good form you've done enough
• Ask a trainer or spotter to keep an eye on the curve in your lower back

Squats are a highly effective strengthening exercise. It is unfortunate that occasionally they can contribute to injury. An awareness of the risk factors for injury and good technique can help ensure squats will remain an important part of your training program and keep you off the physio table.

Stuart McKay
APA Physiotherapist & Owner of Total Physiotherapy

References:
Hartmann H, With K, Klusemann M. Analysis of the Load on the Knee Joint and Vertebral Column with Changes in Squatting Depth and Weight Load. Sports Med. 2013; 43:993-1008

Comfort P & Kasim P. Optimizing Squat Technique. Strength and Conditioning Journal. 2007; 29 (6), 10-13