As to which type of guitar capo will best suit your playing, you will need to match the capo to your guitar, the primary factor being whether you have a flat fretboard, like a nylon-stringed classical or some steel-string acoustics, or if the fretboard is curved, like on most steel-stringed acoustics and electrics.
However, note that other causes of the symptom 'Muscle mass loss' may be possible. Research the causes of these symptoms that are more broader types of symptom than Muscle mass loss: Muscle atrophy (351 causes)
What happens to muscles as we age? As many of us have already noticed, muscle mass decreases as we age. Beginning in the fourth decade of life, adults lose 3%-5% of muscle mass per decade, and the decline increases to 1%-2% per year after age 50.