Purpose of review: Contraction of the adductor pollicis muscle after electrical stimulation (electromyogram) or dynamometry (hand-grip tests) has been evaluated in a variety of clinical conditions as a parameter to assess nutritional status. However, adductor pollicis muscle thickness has not been investigated as an anthropometric parameter.
Recent findings: Prolonged immobilization and non-use of lower and upper limb muscles causes atrophy. Adductor pollicis muscle function is normal in patients with stable chronic obstructive pulmonary disease and multiple sclerosis, whereas the musculature of lower limbs suffers more pronounced functional alterations. Structure and function are relatively preserved in upper limb muscles, probably because of the maintenance of some daily activities involving the arms. Inactivity as a result of a reduction in daily activities is probably the driving factor for these changes. Forearm immobilization for 21 days caused no significant change in muscle morphology, but caused a deterioration in muscle function. Virtually all routinely developed activities requiring opposition of the thumb muscle and repetitive exercise of one muscle group for a given period of time maintain muscle size and function. Apathy is often observed as malnutrition progresses, reducing daily working activity and aggravating adductor pollicis muscle loss besides the muscular catabolism caused by disease.
Summary: This study provides the first estimates of adductor pollicis muscle thickness in normal healthy individuals. The adductor pollicis muscle has a positive correlation with anthropometric variables that estimate muscle mass, but fails to correlate with parameters that estimate fat mass. This measurement is now being evaluated as an anthropometric parameter in clinical studies.