Gluteal activation and increased frontal plane projection angle during a step-down test in young women

Abstract

Purpose. To investigate how the activation of gluteus maximus and gluteus medius interacts with different frontal plane projec tion angles (FPPA) in healthy young women presenting dynamic knee valgus in one limb while performing the stepdown test. Methods. The total of 18 young women presenting FPPA > 15° during the stepdown test in one limb (dynamic knee valgus) were assessed. The other limb should present less than 15° for comparisons. The amplitude of muscle activation was assessed through surface electromyography of gluteus medius and gluteus maximus during 8 subsequent weight bearing stepdown tests. Results. FPPA was positively correlated with gluteus maximus activation and with the assessed side showing FPPA > 15°, which also revealed increased activation of gluteus maximus. No differences were noted for gluteus medius. The principal component analysis explained 73% of the variance in 2 components, with gluteus maximus explaining 48% of the variance on the 1st component. Gluteus medius explained 25% on the 2nd component. Conclusions. Gluteus maximus seems to be a major component to explain dynamic knee valgus in women without symptoms of patellofemoral pain, probably owing to weakness and lack of stabilization of other proximal muscles of the hipknee complex during the task.

Effects of adding neuromuscular electrical stimulation to functional training on muscle recruitment, pain reduction, and knee joint function in patellofemoral pain syndrome patients

“…The VMO electrode was placed 4 cm above and 3 cm medial to the patella, at a 55° angle relative to the femur longitudinal axis. [17] During clam opening and closing, single and double bridge training, the NMES electrodes were attached to the GMAX to activate GMAX, the GMAX electrode was placed at the midpoint of the muscle belly in the line between the second sacral vertebra and the greater trochanter of the femur, [18,19] and the muscles contracted during training when an electric current passed through them, and rested when the electric current ceased. In order to avoid the muscle fatigue.…”

Weak Hip Strength Increases Dynamic Knee Valgus in Single-Leg Tasks of Collegiate Female Athletes

“…11,13 This provides evidence that clinicians should consider strengthening the hip to reduce knee injuries in collegiate female athletes participating in volleyball, basketball, and soccer. 1,9,11,[13][14][15] Increased hip strength leads to a reduction in injury risk at the knee, including pathologies like anterior cruciate ligament sprains, patellofemoral pain syndrome, and lateral ankle sprains, in addition to any causes for pain. [1][2][3][4]6,[9][10][11][13][14][15] These injuries occur due to malalignments that increase abnormal stressors over time, eventually injuring the structures.…”

Effects of differences in femoral anteversion and hip flexion angle on hip abductor muscles activity during clam exercise in females

“…Decreased strength and activity of the hip abductor muscles are associated with lower back [1], hip [2,3], and knee [4,5] pain and the risk of sports injuries, such as anterior cruciate ligament injuries, patellofemoral pain, and ankle instability [6][7][8][9][10][11]. Therefore, exercise training programs have emphasized increasing the hip abductor muscle activity during rehabilitation after sports injuries of the lower extremities and trunk [4,[8][9][10][11][12][13][14][15][16][17][18].…”