Muscle Size for Health Care
Overview
Muscle Size is considered here as the thickness of a muscle (“Muscle Thickness”) as measured by ultrasound at predetermined muscle locations. Research has shown that Muscle Thickness can be considered a surrogate for Muscle Mass/Volume, particularly in the lower limbs 1-3.
Currently we are able to assess muscle size of the thigh, both the Rectus Femoris (RF) and the Vastus Lateralis (VL). Future assessments will include other muscles of the lower limbs, the Hamstrings (HL) and the Calf/Gastrocnemius (GS).
Why is Muscle Size Important?
Skeletal muscle has a little known - but powerful - impact on a range of health issues. It is a unique and extensive body tissue that on average makes up approximately 40% of body mass, depending on gender, age and physical fitness. While it is typically only thought of as having a physical, movement-oriented role, in reality the skeletal muscle system is fundamental to life 4. It contributes to crucial health related functions including breathing, protein metabolism, digestion, blood circulation, immune system status, blood glucose regulation, and overall quality of life.
Why is Muscle Size Important in Health Care?
The size of our muscles, therefore, is an important component of the health of our muscles (Our “MuscleHealth”) and makes an essential contribution to wellbeing at any age and any level of fitness and mobility. However, muscle mass decreases on average by as much as 10% per decade between 30 and 70 years of age and up to 15% per decade thereafter 5, 6. In the healthcare field, there is now increasing awareness of the importance of slowing this decline in order to reduce the risk of a range of chronic health conditions. This is particularly important in older, more frail populations. For example loss of muscle mass is an important determinant of survival in cancer and cardiac disease. However, by far the greatest muscle-related health risk is “Sarcopenia”, the clinical term for loss of muscle tissue that occurs as a natural part of the aging process (‘Sarco-’ = ‘Flesh’, -’Penia’ = ‘Poverty’). It is a health- and age-related condition, regarded as the single most frequent cause of late-life disability.
While loss of muscle is, ultimately, inevitable with aging, the speed of such losses can be delayed and even transiently reversed with appropriate interventions such as strength training 7, 8. The key to achieving this, however, is the ability to easily monitor such changes.
Quantifying muscle mass has, until now, required expensive, complex and relatively inaccessible equipment such as MRI, DEXA or BIA. MuscleSound, in contrast, is a rapid, convenient and comfortable method of determining muscle size. Result can be downloaded within seconds to a tablet or laptop for later analysis or historical context.
In summary, Muscle Size is important in Health Care...
- Because it allows the monitoring of muscle mass levels related to the progression of sarcopenia
- In free-living populations
- In chronic disease patients
- In ICU patients
- Because it can determine the impact of clinical strengthening/rehab programs on muscle mass levels in patient populations
- Because it can determine the impact of nutritional rehab programs on muscle mass levels in these populations
- Abe, T., et al. Morphological and functional relationships with ultrasound measured muscle thickness of the lower extremity: a brief review. Ultrasound 23: 166–173, 2015
- Abe, T., et al. Ultrasound assessment of hamstring muscle size using posterior thigh muscle thickness Clin Physiol Funct Imaging 36: 206–210, 2016
- Ogawa, M., et al. Ultrasound Assessment of Adductor Muscle Size Using Muscle Thickness of the Thigh. Journal of Sport Rehabilitation 21: 244-248, 2012
- Wolfe, R., The underappreciated role of muscle in health and disease. Am J Clin Nutr 84: 475–82, 2006.
- Roth SM, et al. Strength training for the prevention and treatment of sarcopenia. J Nutr Health Aging 4: 143-55, 2000
- Malafarina V, et al., Sarcopenia in the elderly: Diagnosis, physiopathology and treatment. Maturitas 71: 109–114, 2012.
- Phillips WT & Hazeldene R. Strength and muscle mass changes in elderly men following maximal isokinetic training. Gerontology. 42: 114-120, 1996
- Peterson MD, Sen A, & Gordon PM. Influence of resistance exercise on lean body mass in aging adults: A Meta- Analysis. Med. Sci. Sports Exerc., Vol. 43, No. 2, pp. 249–258, 2011.