Change in muscle thickness during exercise to stabilize the hip joint against a load in the ventral direction of the femoral head.

Only 10 healthy young men were tested, and all had no leg or spine problems, so the findings do not apply to people with hip pain or instability. Measurements were made lying supine, not during standing or walking, which are the positions where femoral head translation causes problems. The study measured ultrasound thickness, not direct muscle activity, and the authors state thickness change cannot show the degree of muscle activity. Slight hip extension movement occurred despite fixation, so the ventral muscles may have acted as hip flexors rather than only stabilizers. The probe may not have been vertical to the muscle. The anterior gluteus minimus may also have been squeezed by superficial muscle. These could affect thickness.

No potential conflicts of interest were disclosed. The work was supported by JSPS KAKENHI Grant Number JP19K24181.

Do not conclude that anterior gluteus minimus exercise prevents or treats hip joint disease caused by femoral head translation. The study measured muscle thickness in 10 healthy men lying supine, and the authors state that thickness change cannot show the degree of muscle activity.