Thinning of the plantar soft tissue under the metatarsal heads in older adults is linked to both hallux valgus and lesser toe deformities, according to a case-controlled study published in the July 2011 issue of the Journal of Orthopedic Research.
Researchers from the University of Wollongong in Australia used ultrasound to measure non-weightbearing total soft tissue and fat pad thickness at the heel, first metatarsal head, and fifth metatarsal head in 312 men and women older than 60 years. They assessed all participants for the presence of hallux valgus or lesser toe deformities and compared the 108 individuals with these findings to gender-, age-, and BMI-matched controls.
Those with hallux valgus had significantly reduced total soft tissue thickness under the first metatarsal head compared with controls, while those with lesser toe deformities had a significant reduction in soft tissue thickness under the fifth metatarsal head.
Fat pad thickness, however, did not differ between cases and controls, leading
authors to suggest that musculotendinous complex compromise might reduce toe
function in those with toe deformities.