Sling exercise training is a multifunctional training program involving various exercises for athletes. VMO activity and VMO : VL ratio of EMG may be effective indicators to assess the training effect. It is unclear what a suitable and safe movement of the exercises can improve VMOmuscle strength. The presence of effective therapeutic exercises of knee extension and hip adduction creates a dilemma for treating the patients with PFPS. Hip adduction exercise is also suggested for patients with PFPS.

, and they combined closed kinetic squats with isometric hip adduction exercises and found that the integrated movement more efficiently recruited quadriceps activity than did closed kinetic squat exercises alone. This is a finding supported by Earl et al. The hip adductor muscle training is often added to rehabilitation program of PFPS, because it can facilitate VMO contraction, which is preferentially recruited in hip adduction exercises. It can facilitate increasing VMO muscle activity because the origin of VMO muscle connects to the insertion of the hip adductor muscles. Hip adduction exercise is another specific therapeutic exercise for PFPS patients. An evidence-based approach indicated that VMO training, using open or closed kinetic chain exercise, effectively prevents and alleviates PFPS. Previous study has indicated that the value of VMO : VL ratio in patients with PFPS was 0.54 : 1 this is possibly because imbalance of VMO and VL muscle activities causes insufficient medial patellar strength, which induces patellar maltracking in PFPS. The electromyography (EMG) study represented that the ideal VMO : VL ratio for healthy individuals during knee extension is 1 : 1. During a knee extension exercise, the patella is pulled by the quadriceps muscle and the cranial slides within the femoral trochlear groove, and the exercise is an efficacious treatment for an imbalance of VMO and VL muscles, which is thought to be present in patients with PFPS, to stabilize patellar tracking. Previous study demonstrated that knee extension exercises with knee flexion angles between 0° and 60° were recommended for VMO activation. ĭifferent strengthening techniques have been suggested for VMO training, which can be categorized into open or closed kinetic chain exercises. Empirical evidences represented that an imbalance of VMO and VL muscle activities leads to excessive lateral tracking of the patella and rubbing of the lateral femoral condyle, which causes articular surface erosion and degeneration and induces pain. Because of muscle imbalance between the vastus medialis oblique (VMO) and vastus lateralis (VL), the VMO cannot antagonize the VL, resulting in patellar maltracking. Although the causes of PFPS are not clearly understood, this syndrome is related to abnormal patellar arrangement and biomechanics, for example, increased Q angle, patellar maltracking, excessive foot pronation, and excessive external torsion. Patellofemoral pain syndrome (PFPS) is a musculoskeletal disorder that often occurs in the lower extremities of athletes and has a high prevalence in women aged 18–35 years. It also had an appropriate VMO : VL ratio similar to sling-based hip adduction exercise and had beneficial effects on PFPS. The sling-based closed kinetic knee extension exercise produced the highest VMO activation.

VMO activations during the sling-based open and closed kinetic knee extension exercises were significantly higher ( P = 0.04 and P = 0.001) than those during hip adduction exercises and VMO : VL ratio for the sling-based closed kinetic knee extension and hip adduction exercises approximated to 1. Thirty male (age = 21.19 ± 0.68 y) and 30 female (age = 21.12 ± 0.74 y) patients with PFPS were recruited. The VMO and VL activations and VMO : VL ratios for the three exercises were analyzed and compared. Sling-based open and closed kinetic knee extension and hip adduction exercises were designed for PFPS, and electromyography was applied to record maximal voluntary contraction during the exercises.

To examine what changes are caused in the activity of the vastus medialis oblique (VMO) and vastus lateralis (VL) at the time of sling-based exercises in patients with patellofemoral pain syndrome (PFPS) and compare the muscular activations in patients with PFPS among the sling-based exercises.

Whats better quad sweep or vmo