If in those which require the strength and vivacity of youth, I readily admit the charge.” [2] Although aging has always been perceived as a paradox that plagues humanity, the idea of formulating preventative treatments didn't advance until the latter part of the 20th century.
With the rapid advancement of today's technology and the unprecedented growth rate of the world's older population, the drive of the scientific community to delay the aging process has significantly increased.
Muscle strength appears to be a critical component in maintaining physical function, mobility, and vitality in old age, which is why it's imperative to identify and study contributing factors of dynapenia.
More recent studies by Xue et al.[15] have observed that faster decline in hip flexor and grip strengths individually predicted mortality after accounting for potential contributors.
Lack of consensus upon how to properly diagnose the disease has prevented practitioners from determining if muscle weakness likely plays a role in an individual's disability or poor physical performance.
[citation needed] Possible biological contributors to dynapenia include the nervous system’s deteriorating control of voluntary skeletal muscle activation and a decreased number of functioning motor units.
Studies involving the dissection of cadavers have uncovered a 43% decrease in the cell body size of neurons found in the premotor cortex compared to those of younger adults.
[25] New studies have recently verified this finding in living subjects using high resolution magnetic resonance imaging (MRI).
Particularly, impairments in the release of calcium (Ca2+) from the sarcoplasmic reticulum have been suggested to explain why decreased muscle quality is so prevalent in older adults.
In contrast, participants who consumed more protein (mean: (≥1.0 g/kg body weight/d) than the RDA had a lower risk of developing mobility limitations over the 6 year follow-up.
[48] Resistance training has been shown to greatly influence virtually all of the strength related physiological mechanisms of the nervous and skeletal muscle systems - even into very late life.
The other factor is a direct relationship between increased resistance training volume, which is the total number of exercise sets performed in a session, and improvements in lean body mass.
By defining strength cutoff values and establishing a clinical definition of dynapenia, treatment and prevention plans could be developed to decrease the physical limitations of older adults.
The creation of an agreed-upon definition of dynapenia could give clinicians the ability to diagnose patients with decreased muscle function and expand research on the subject by providing a universal standard, which in turn could lead to the development of effective interventions and treatment options.
[1] Gathering a firmer understanding of what causes dynapenia will help determine the degree of variance in the biological contributions of participants, and provide insight into how treatment options may be adapted to fit patients’ unique needs.