Kellie Huxel Bliven and Karrie L. Hamstra-Wright
Karrie L. Hamstra-Wright and Kellie Huxel Bliven
The gluteus medius (GM) is thought to play an important role in stabilizing the pelvis and controlling femoral adduction and internal rotation during functional activity. GM weakness, resulting in decreased stabilization and control, has been suggested to be related to lower extremity dysfunction and injury. Many clinicians focus on strengthening the GM to improve lower extremity kinematics for the prevention and rehabilitation of injury. An indirect way to measure GM strength is through electromyography. It is generally assumed that exercises producing higher levels of activation will result in greater strengthening effects.3 Understanding what exercises result in the greatest level of GM activation will assist clinicians in their injury prevention and rehabilitation efforts.
Focused Clinical Question:
In a healthy adult population, what lower extremity exercises produce the greatest mean GM activation, expressed as a percentage of maximum voluntary isometric contraction?
Karrie L. Hamstra-Wright, Burcu Aydemir, Jennifer Earl-Boehm, Lori Bolgla, Carolyn Emery and Reed Ferber
Hip- and knee-muscle-strengthening programs are effective in improving short-term patient-reported and disease-oriented outcomes in individuals with patellofemoral pain (PFP), but few to no data exist on moderate- to long-term postrehabilitative outcomes. The first purpose of the study was to assess differences in pain, function, strength, and core endurance in individuals with PFP before, after, and 6 mo after successful hip- or knee-muscle-strengthening rehabilitation. The second purpose was to prospectively follow these subjects for PFP recurrence at 6, 12, and 24 mo postrehabilitation.
For 24 mo postrehabilitation, 157 physically active subjects with PFP who reported treatment success were followed. At 6 mo postrehabilitation, pain, function, hip and knee strength, and core endurance were measured. At 6, 12, 18, and 24 mo, PFP recurrence was measured via electronic surveys.
Sixty-eight subjects (43%) returned to the laboratory at 6 mo. Regardless of rehabilitation program, subjects experienced significant improvements in pain and function, strength, and core endurance pre- to postrehabilitation and maintained improvements in pain and function 6 mo postrehabilitation (Visual Analog Scale/Pain—pre 5.12 ± 1.33, post 1.28 ± 1.14, 6 mo 1.68 ± 2.16 cm, P < .05; Anterior Knee Pain Scale/Function—pre 76.38 ± 8.42, post 92.77 ± 7.36, 6 mo 90.27 ± 9.46 points, P < .05). Over the 24 mo postrehabilitation, 5.10% of subjects who responded to the surveys reported PFP recurrence.
The findings support implementing a hip-or knee-muscle-strengthening program for the treatment of PFP. Both programs improve pain, function, strength, and core endurance in the short term with moderate- and long-term benefits of improved pain and function and low PFP recurrence.