How to utilize body composition for evaluating muscle mass and effectiveness
Body composition analysis is a key tool for understanding a subject's muscle level! Understanding how much effective strength a person has makes it possible to provide a better level of care, and guide treatment more effectively.
After completing a comprehensive scan using Charder's Body Composition Analyzers, you will receive easy-to-understand indicators of a subject's whole-body and segmental muscle mass, as well as an estimate of their grip strength calculated taking into account cellular strength and overall health. These results can be used to identify areas that may be weaker due to muscle loss, and quantify risk through observing trends in both mass and strength.
Generally speaking, muscle can be divided into three types - cardiac, smooth, and skeletal. Of the three, skeletal muscle is used to move the body, and a decrease of skeletal muscle can exacerbate risk of falls and injury, especially for elderly subjects. There are several different skeletal muscle indicators provided for professional use:
The Muscle-Fat module displays the subject's proportion of muscle and fat. The black line gets longer with more mass, and shorter with less mass - if SMM (Skeletal Muscle Mass) results fall under normal range, that may be a sign of insufficient muscle.
Skeletal Muscle Index
If a specific cut-off point is required for diagnosis of sarcopenia, the SMI (Skeletal Muscle Index, using whole-body skeletal muscle) and ASMI (Appendicular Skeletal Muscle Index, using only muscle in the arms and legs) can be used as well.
SMI is the weight of skeletal muscle normalized for height. So for example, a person with 35.3 kg standing 182.5 cm tall would calculate their SMI as follows:
35.3 / (1.825*1.825) = 10.6
The cut-off point for defining sarcopenia can vary for different countries and populations, as different groups of people may have differing body composition as well as definitions for insufficient strength.
Another common method of evaluating sarcopenia is using ASMI, which does not use the entire SMM of the body, but rather the total weight of muscle in the arms and legs only, normalized for height. ASMI will thus inherently be smaller than SMI, as it does not include the trunk. Similar to SMI, different countries and populations will utilize their own cut-off points.
It is very important to make sure if you're using whole-body muscle (SMI) or appendicular muscle (ASMI) for evaluation, as using the wrong standard could result in mistaken evaluation - if you judge someone's ASMI results using SMI standards, you could very easily evaluate them as "under", rather than "normal"!
Research indicates that muscle quality declines more quickly than muscle mass in elderly populations. For example, in this paper published in the Journal of Gerontology exploring "The Loss of Skeletal Muscle Strength, Mass, and Quality in Older Adults", it was found that decline in strength was much more rapid than the concomitant loss of muscle mass in seniors. This would indicate that measurement of muscle mass is important but possibly insufficient for evaluation of sarcopenia or risks of falling that accompany decline in muscle strength.
Charder's unique Muscle Quality module utilizes a combination of muscle measurement and cellular health to calculate the client's grip strength, which is a widely accepted indicator of full-body strength. This differs from traditional grip strength dynamometers in that it avoids potential pitfalls caused by significant differences in grip measurement results caused by hand size or lack of coordination, analyzing at a cellular level instead.
If a subject's calculated Muscle Quality (represented by kgf of grip strength) declines continuously, it may be a sign of decreased muscle effectiveness, even if no significant decrease in muscle mass has been observed yet!
Effective utilization of professional body composition analyzers make it easy to identify and track muscle deficiency or decreasing effectiveness. This is of particular importance for screening purposes, as well as tracking recovery and rehabilitation. Contact us to learn more!