Comparison of neuromuscular and abductor strengthening exercises in the hip abductor muscle strength: A randomized controlled trial

Decreased hip abductor strength has been associated with a range of knee pathologies. Hip abduction muscles play a critical role in providing pelvic stability and leg alignment during weight-bearing movements by eccentrically controlling hip adduction. Poor hip control can result in abnormal lower extremity motions, and studies have reported that lower limb problems such as patellofemoral pain (PFP),1 knee osteoarthritis (OA),2 and ACL injuries,3,4 are linked with altered lower limb kinematics, with a higher prevalence in females.5 A body of literature suggests that increased dynamic knee valgus is associated with hip abductor weakness.6 Moreover, several studies have shown that interventions such as neuromuscular training (NMT) programs can lower the incidence of lower extremity problems. An NMT program emphasizing optimal alignment of the trunk and lower limb joints relative to each other, along with quality movement performance while dynamically and functionally strengthening the lower limb muscles, may be better at enhancing hip muscle strength. Therefore, we performed a randomized controlled trial evaluating the effects of NMT in comparison to a progressive resistance training program (PRT) on muscle hip abductor strength. To investigate whether a 6-week NMT can improve the hip abductor muscle strength better than a PRT. The present study was a single-blind randomized controlled trial aiming to investigate the effects of two interventions on asymptomatic females, aged 18-35 years old. Sample size calculation revealed that 26 participants per group were required. Following a baseline assessment, 52 participants were randomly assigned to either a 6-week PRT or NMT intervention involving 3 sessions per week. The PRT intervention consisted of hip abductor exercises performed in an open kinetic chain, with three to four sets of ten repetitions at a target intensity of 6-8 RPE.7,8,9 The NMT intervention focused on improving functional stability, balance, proprioception, strength, agility, postural function, and orientation,10,11 consisting of weight-bearing positions. The participants were assessed after the 6-week intervention. Mean peak hip abduction, concentric and eccentric torque, were measured by a blinded assessor on a Biodex System 3 Pro isokinetic dynamometer at 60°/s. Dependent t-tests showed significant improvements in CON60, and ECC60 after both interventions (<0.05) (Table 1). Two-way mixed ANOVAs did not reveal statistically significant Group*Time interactions for the CON60 and ECC60. The results from the comparison of the effectiveness of each intervention are visually presented in Figs. 1 and 2. Download : Download high-res image (114KB)Download : Download full-size image Both PRT and NMT improved abductor strength. However, both groups had similar overall differences in strength before and after the intervention. Since no intervention is superior to the other, neuromuscular training might be clinically preferred as it combines dynamic and functional strengthening of the individual.