Can Exercise Build Muscle and Strength in People with Hip OA?

Are weakness and atrophy a cause of pain or a result of pain? It can be both but I find clinicians tend to focus on the former, blaming a patient’s pain on their weakness. If someone is in pain, their activity level tends to drop. If a muscle is not stimulated adequately, it will adapt negatively. We see this in patients with hip OA, as they often exhibit muscle atrophy, fatty infiltrate, and weakness in their symptomatic hips. Regardless of the cause, those findings are problematic, as they reduce the physical capacity of the individual. Therefore, a common aim in clinics is to improve muscle and strength and reduce fatty infiltration. Do the gluteals need to be specifically targeted to achieve those outcomes? This recent study (PMID: 36309690) compared targeted resistance training with a sham exercise intervention to help answer the question.

Twenty-seven participants with symptomatic hip OA were allocated to one of two groups. The targeted group's exercises were progressed as follows: (1) gait retraining; (2) glut min strengthening through split squat and bridge exercises; and (3) pelvic stability and global strengthening, involving high-intensity strength exercises, such as isometric hip hitches, double-leg squats and deadlifts at RPE 5-7. The sham group completed a general low-intensity lower-body multistage (stages 1–3) exercise program, aimed at multiple muscle groups and included unloaded (mostly seated) gluteal, quadriceps, and calf exercises. The programs lasted for 12 weeks.

It should come as no surprise that the targeted group experienced superior improvements in hypertrophy. The sham group saw no improvements in hypertrophy. Strength gains were similar for both. I think this study misused the term sham. This was a low vs. moderate intensity resistance training trial. The biggest takeaway is people with symptomatic hip OA can build muscle in three months with moderate-intensity training. If a patient is deconditioned, any resistance training will improve strength simply by improving motor recruitment efficiency, but they will plateau quickly. The literature continues to support the use of moderate to high-intensity resistance training in a clinical setting.