Ultrasound Findings of Thumb Muscles in 1st Carpometacarpal Osteoarthritis

The thickness of the thenar eminence muscles (longitudinal thickness of the first dorsal interosseous muscle (FDI), abductor pollicis brevis (APB), and opponens pollicis (OPP)) was measured using musculoskeletal ultrasound.

Muscle strength in both hands was evaluated using grip strength measured with a dynamometer (Jamar Hydraulic Hand Dynamometer, Nottinghamshire, UK)

Pressure pain threshold (PPT) for painful and non-painful finger joints was assessed using a hand-held algometer