Asymmetry

Asymmetry is defined as the absence of symmetry, or when one side is not the same as the other. This is something that can be considered in everything we see or do. When looking at the human body we can consider symmetry in a variety of things, for example, symmetry of the: face, muscle, posture, strength, flexibility, etc. The most common asymmetry experienced hand dominance, where one hand or side of the body is more competent than the other, known as ‘Laterality’.  A key feature that Bodybuilders and Figure model competitors are judged on is symmetry.

But how important is symmetry in life?

Asymmetry is considered the 2^nd biggest precursor to future injury (behind previous injury). If there is a hindrance in movement, whether it be to do with strength, flexibility, or mobility from the left to right side, there is a large chance, that if left untreated, some kind of injury or problem will develop. This is largely due to imbalances imposed on the body, by favoring muscles that should not be favored, the following issues can occur:

• Tightness
• Overuse
• Growth
•  Irritation
•  Pain 

Depending on how long a lateral asymmetry is left untreated, correction can be a relatively simple task, however, if left unattended, can become very problematic with an extensive rehab process. A simple postural analysis or movement screen can identify asymmetries, which can be used to prescribe corrective work to address the issues. Corrective work for any area is infinite and widely varied not just between areas of injury, but from the coach whom prescribes it. Corrective work can consist of:

•  Stretching - PNF and AIS stretching have been shown to be the most effective forms of stretching
• Isometric strengthening
• Dynamic Strengthening of gross and synergistic muscle groups
•  Stabilizing
• Repatterning movements - basically teaching how to perform activities from a foundational level. Repatterning is the most common corrective exercise. Without functional movement as a base, an athlete is typically overpowered due to their reliance on functional performance and skill (Grey Cook). If you build a house with a poor foundation, it will likely collapse.

However, asymmetry is not only important when addressing the left and right sides. If we look at the body from front to back, we typically find numerous asymmetries. The most common problems we see are:

• Quadricep dominance over the Hamstrings - Quad dominance is very common, and is mainly caused by overuse. People who consistently squat or lift without also working the hamstrings are the most commons subjects with this asymmetry, causing them issues with hip hinging (bending at the hips) and very often low back pain due to excessive pressure on the pelvis and lumbar spine. A worst case scenario of hamstring to quad strength should  be 3:5, if the hamstrings are 60% weaker than the quads, the subject is at greater risk of experiencing injury.
•  Chest/Pectoral dominance over the Scapula (Shoulder Blades) - Pectoral dominance again is very common and is typically caused by overuse of the pecs, and poor posture, it causes tightening of the chest and anterior rounding of the shoulders, leading to: Kyphosis (excessive curve of upper spine), restricted shoulder mobility, poor strength, postural changes, and in many cases, breathing issues.

 Again, this type of asymmetry can be relatively simple to deal with, but if left untreated can cause major issues.

The ‘Janda Approach’ and ‘Crossed Syndrome’ are theories that deal specifically asymmetries of the anterior and posterior. Janda suggests that if you look at pain in one area of the body, the spot directly anterior will be having the opposite issues, for instance chest tightness through the pectorals will cause scapula weakness creating rounding of the shoulders. He then suggest the joints above or below will be having the opposite issues, so a subject with: tight pectorals and weak scapula/rhomboids, will likely experience tight trapezius and weak neck flexors, or tight lumbar spine and weakened abdominals.

Corrective exercises are much like those used for lateral asymmetries, with the most effective typically being aggressive stretching of the dominant muscle, and strengthening/repatterning the weakened muscle groups.

As stated earlier, without intervention, asymmetry is the second biggest precursor to future injury. It is therefor very necessary to identify asymmetries before they are able to progress, by performing some form of postural analysis or movement screening, even the smallest problem can be identified.

Cook, G., Athletic Body in Balance. Human Kinetics, 2003.

Janda, V., The Janda Approach to Chronic Pain Syndromes. www.jandaapproach.com. 2012