THE NEUROMUSCULAR ACTIVITY DIFFERENCES OF QUADRICEPS AND HAMSTRING MUSCLES DURING DROP-VERTICAL JUMP AND 180-DEGREE PIVOTING MANOEUVRE: A QUASI- EXPERIMENTAL STUDY

Abstract

Background: The drop-vertical jump (DVJ) is one of the most common screening tools used for ACL injury risk, whilst another screening tool which has been used for the risk of anterior cruciate ligament (ACL) injury is the side-cutting manoeuvre. However, it was reported that 180-degree pivot provides a more realistic game risk than side-cutting. Whilst a limited number of studies have investigated the biomechanical demands of the 180-degree pivoting manoeuvre, no studies have investigated its neuromuscular requisites. Aim of the study: The study aimed to investigate the neuromuscular activity differences of hamstring and quadriceps muscles during DVJ and 180-degree pivoting manoeuvres in healthy adults. Design: A quasi-Experimental study, within-subjects design. Methods: This study includes 32 physically active adults (aged 20-50 years-old) who were uninjured, the participants were recruited equally from the two genders. The participants were recruited in a single session to measure their hamstring and quadriceps muscle activity during DVJ and 180-dgeree pivoting manoeuvre. Results: The study’s results showed that there was no statistically significant difference in the quadriceps muscles during DVJ and 180-degree pivoting manoeuvre (P-value=0.556, 0.779) respectively. Whilst there was a statistically significant difference in the hamstring muscles during DVJ and 180-degree pivoting manoeuvre (p-value=002, 003) respectively. The second outcome measured vastus lateralis-semitendinosus differences, no statistically significant difference was found during the DVJ (p-value = 0.360), a statistically significant difference was found during the 180-degree pivoting manoeuvre (p-value < 0.001). Conclusion: The findings suggest that the quadriceps muscles do not seem to have a significant effect during dynamic tasks, whilst the hamstring muscles were the dominant muscles during both tasks, especially during the 180-degree pivoting manoeuvre. This may indicate that the hamstring muscles are the muscles responsible for stabilising the knee joint.