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)
Some muscle mass loss with aging is inevitable, but that doesn't mean you have to end up with sarcopenia, a condition in which loss of muscle mass is associated with a decline in muscle function, according to Roger Fielding, Ph.D., director of the Nutrition, Exercise Physiology and Sarcopenia Laboratory at Tufts University.