According to preliminary research by the Diagnosis Foundation, virtually everybody has at least one set of muscles with imbalanced strength. What does this mean and what are the implications?
What is balanced muscle strength? There are 3 types of muscle balance that may be looked at:
- Right side vs left side – Any muscles on one side of the body should be within 10% of the same strength as the same muscle on the opposite side of the body.
- Muscles around a joint – All of the muscles around any given joint need the correct amount of strength pulling in each direction. For example, the muscles that move your thigh backward, need similar strength compared to the ones that move your thigh forward, to the outside, to the inside, rotating the thigh inward and outward.
- Muscles along the kinetic chain – Movements start in one part of the body and moves along a ‘chain’ to some end point. For example, a baseball batter starts their power stroke where their feet meet the ground. They generate some of the power that will eventually end up at the point where the bat meets the ball at those points of contact with the ground. Additional power is added to the force generated at the ground through contributions from the ankles, knees, hips, waist etc. on up through the wrists and fingers. The total force put into the bat is the sum of all of these combined muscles working in a highly coordinated sequence or ‘chain’. Should any of the muscles along this chain not have enough strength to properly carry the force generated earlier in the chain along to the next link, energy will be lost and the maximal force put into the bat will be decreased because of this ‘weak link’.
What are the implications of imbalanced muscle strength?
1. Right vs. left side – When muscles connected or having influence on the spine are imbalanced, issues such as scoliosis can develop.
2. Muscles around a joint – If one muscle around a joint is stronger or weaker than the rest, the bones of that joint will not remain centered properly when you move. This causes a shift in the biomechanics of your joint which initially results in a loss of athletic performance (decreased power, speed & endurance).
If allowed to progress, the joint will tug to one side. This can cause stretching of the soft tissues and damage. At this stage, you might notice clicking in a joint, or that certain activities result in pain. As the tissues that hold you joint together become stretched your joint becomes ‘sloppy’ or loose. This leaves you more susceptible to injuries. If left uncorrected, the amount of damage in the affected joint accumulates, eventually resulting in joint disease or osteoarthritis.
How do I know if I have balanced muscle strength in my joints? There are a wide range of tests that can be done to evaluate muscle strength. The key to understanding this issue is to do testing that isolates individual muscles.
To accomplish this, subjects are placed in very specific starting positions and asked to do a very specific motion that puts most of the work load on one group of muscle fibers, and minimizes the contributions from others. For general strength purposes, do a test that measures the maximum force you can generate in 1 repetition.
State of the art testing where documentation is required for insurance or legal cases typically involves sophisticated equipment (i.e. Cybex, Biodex). While muscle strength testing with this type of equipment can be extremely accurate, it tends to be limited in the number of different muscles that can be measured and takes a relatively large amount of time and money to perform.
Manual muscle testing, with or without measurement or recording devices, offers a much broader range of muscles that can be measured and can be done in a much quicker time frame and lower cost. Accuracy will not be as good with manual testing, but it is still considered to be of good quality with “good internal and external validity” (1). In a balanced muscle strength screening, a skilled examiner can test ten to twenty muscles on both limbs in less than 10 minutes.
Where can I get this done? Professional sport teams and olympic athletes get tested for individual muscle strength on a regular basis. The typical doctor’s office however, does not do this type of testing. You will have to search for a health care provider who does this type of work. This service is currently available through our yoga studio by obtaining a YogAnalysis.
You can also learn how to do muscle strength testing yourself through our certification courses in YogAnalysis. These courses will teach you how to do strength testing on dozens of muscles throughout the body. Additionally, you will learn how to measure Ranges of Motion (ROMs), what to do for corrective exercises/stretches and how you might apply this information to a yoga program. For additional information see here.