Site-Specific Muscle Loss in the Abdomen and Anterior Thigh in Elderly Males with Locomotive Syndrome.

Although locomotive syndrome (LS) is a condition of reduced mobility, little information is available regarding the loss of site-specific skeletal muscle mass. The aim of the present study is to examine site-specific muscle loss in elderly males with LS. A total of 100 men ranging in age from 65 to 74 years were divided into two groups (LS and non-LS) using LS risk tests including the stand-up test, two-step test, and the 25-question geriatric locomotive function scale Muscle thickness (MTH) at eight sites-anterior and posterior thigh (AT and PT, respectively), anterior and posterior lower leg (AL and PL, respectively), rectus abdominis (RA), anterior and posterior upper arm (AU and PU, respectively), and anterior forearm (AF)-was evaluated using B-mode ultrasound. Furthermore, the 30-s chair stand test (CS-30), 10-m walking time, zig-zag walking time, and sit-up test were assessed as physical functions. There were no significant differences in age and body mass index between the LS and non-LS groups. The percentage of skeletal muscle was lower in the LS group than in the non-LS group. Although there were no differences in the MTH of AU, PU, AF, PT, Al and PL, site-specific muscle loss was observed at RA and AT in the LS group. CS-30, 10-m walking time, zig-zag walking time, and sit-up test in the LS group were all worse than those in the non-LS group. The MTHs of RA and AT were both correlated to those physical functions. In conclusion, the LS group had site-specific muscle loss and worse physical functions. This study suggests that site-specific changes may be associated with age-related physical functions. These results may suggest what the essential characteristics of LS are.