Immediate effects of real time feedback and kinesiotaping on kinematics and muscle activity in athletes with dynamic knee valgus

Dynamic knee valgus (DKV) is a significant risk factor for anterior cruciate ligament (ACL) injuries. Real-time feedback (RTF) and Kinesio taping (KT) are common interventions used to prevent DKV. This study aimed to compare the immediate effects of RTF, with and without KT, on the kinematics and muscle activity in athletes with dynamic knee valgus. This randomized controlled trial study included 34 male athletes aged 20–25 years with DKV (> 10°) from jumping sports (handball, basketball, and volleyball) who were randomly assigned to two groups: RTF (age 21.94 ± 2.56 years, height 184.35 ± 5.27 cm, weight 74.50 ± 6.75 kg) and RTF + KT (age 22.29 ± 1.86 years, height 183.05 ± 6.01 cm, weight 73.50 ± 5.48 kg). Dynamic knee valgus was screened using Kinovea software during a landing from a 32 cm platform. All participants performed step-down, lateral step-down, double-leg squat and single-leg squat exercises under RTF and RTF with KT conditions. All kinematics and electromyographic variables were assessed during the single-leg vertical drop jump (SL-VDJ) task. Knee flexion, hip flexion, knee valgus and ankle dorsiflexion angles were measured by an IMU system and feedforward activity of hip and knee muscles was measured by an EMG device before and after the exercise intervention. 2 × 2 mixed-model ANOVA (group: RTF, RTF + KT, time: pretest, posttest) was used for data analysis at the significance level of p ≤ 0.05. There was a significant group-by-time interaction effect for peak knee flexion angle (F1,32=5.382, p = 0.027), gluteus medius activity (F1,32=5.9532, p = 0.004), and vastus medialis activity (F1,32=4.288, p = 0.047), with the RTF + KT group exhibiting greater pre-to-post increases in peak knee flexion, gluteus medius activity, and vastus medialis activity, compared to the RTF group. There was a significant main effect of time for peak hip flexion angle (F1,32=7.427, p = 0.010), peak knee valgus angle (F1,32=90.201, p = 0.001), peak ankle dorsiflexion angle (F1,32=4.211, p = 0.048), gluteus maximus activity (F1,32=17.069, p = 0.001), vastus lateralis activity (F1,32=35.908, p = 0.001), medial hamstring activity (F1,32=60.183, p = 0.001), and lateral hamstring activity (F1,32=36.983, p = 0.001), with both groups exhibiting similar changes over time. In summary, RTF + KT and RTF effectively altered kinematic and electromyographic ACL injury risk factors. The RTF + KT intervention demonstrated notable within-group enhancements for multiple measures, particularly in increasing knee flexion and activation of the gluteus medius and vastus medialis muscles. Consequently, while RTF alone constitutes an effective intervention, the RTF + KT combination may offer additional benefits for addressing deficits in knee flexion and specific muscle activations in athletes displaying DKV.