A recent study found that the pectineus and piriformis are codependent in working to stabilize the hip joint.
Researchers monitored 10 patients (five men, five women) as they each completed 13 hip rehabilitation exercises. Eligible participants were healthy adults who were simultaneously evaluated for iliopsoas and gluteus medius muscle activation. Electromyography electrodes inserted under ultrasound guidance into the participants’ muscles recorded the activation levels of the pectineus and piriformis during exercise.
Study results showed that the highest peak and mean pectineus activations were recorded while participants performed a supine hip flexion exercise, 62.8% ± 26.6% maximum voluntary contraction (MVC) and 33.1% ± 17.4% MVC, respectively. The highest peak piriformis activation was observed during a single-legged bridge (MVC, 35.7% ± 25.7%) and the highest mean piriformis activation was recorded during a prone heel squeeze (MVC, 24.3% ± 8.2%). Moderate activation of the pectineus was recorded during single- and double-legged bridges and both phases of a stool hip rotation exercise. Similar piriformis activation levels were found during single-legged hip abduction and resisted hip extension.
“The pectineus was highly activated during hip flexion exercises and moderately activated during exercises requiring rotational hip stabilization in either direction, rather than with internal hip rotation only,” researchers said. “The piriformis was most activated during static external rotation and abduction while the participants’ hips were in slight extension. These observations indicate that … both muscles contribute to hip stabilization.”
Disclosure: See the study for a full list of relevant disclosures.