Immediate Effect of Anterior Cruciate Ligament Protective Knee Taping on Knee Landing Mechanics and Muscle Activations during Side Hops

Athletic taping is widely used in sports to prevent injury. However, the effect of anterior cruciate ligament (ACL) protective taping on neuromuscular control during dynamic tasks remains unclear. Therefore, this study aimed to investigate the immediate effect of ACL protective taping on landing mechanics and muscle activations during side hops in healthy individuals. Fifteen healthy individuals (11 males and 4 females; age, 23.1 ± 1.4 years; height, 175.1 ± 10.4 cm; weight, 66.3 ± 11.2 kg) volunteered to participate in this study. Landing mechanics and muscle activations were measured while each participant performed single-leg hops side-to-side for ten repetitions with and without taping. An optical motion capture system and two force plates were used to collect the kinematic and kinetic data during the side hops. Surface electromyogram recordings were performed using a wireless electromyography system. Paired t-tests were performed to determine the differences in landing mechanics and muscle activations between the two conditions (taping and non-taping). The level of significance was set at p < 0.05. Compared with the non-taping condition, participants landed with a smaller knee abduction angle, greater knee external rotation angle, and smaller knee extensor moment in the taping condition. Given that greater knee abduction, internal rotation, and knee extension moment are associated with a greater risk of ACL injury, our findings suggest that ACL protective taping can have an immediate effect on dynamic knee stability. Clinicians should consider using ACL protective taping to facilitate the use of favorable landing mechanics for ACL injuries.

Effect of lumbopelvic control on landing mechanics and lower extremity muscles’ activities in female professional athletes: implications for injury prevention

Background Lumbopelvic control (LPC) has recently been associated with function, kinesiology, and load distribution on the limb. However, poor LPC has not been studied as a risk factor for lower limb injury in sports requiring frequent jump landings. The present study investigated the effects of LPC on landing mechanics and lower limb muscle activity in professional athletes engaged in sport requiring frequent landing. Methods This study was conducted on 34 professional female athletes aged 18.29 ± 3.29 years with the height and body mass of 173.5 ± 7.23 cm and 66.79 ± 13.37 kg, respectively. The landing error scoring system (LESS) and ImageJ software were used to assess landing mechanics. Wireless electromyography was also used to record the activity of the gluteus medius (GMed), rectus femoris, and semitendinosus. Lumbopelvic control was evaluated using the knee lift abdominal test, bent knee fall-out, active straight leg raising, and the PRONE test using a pressure biofeedback unit. Based on the LPC tests results, the participants were divided into two groups of proper LPC (n = 17) and poor LPC (n = 17). Results There were significant differences between the groups with proper and poor LPC in terms of the LESS test scores (P = 0.0001), lateral trunk flexion (P = 0.0001), knee abduction (P = 0.0001), knee flexion (P = 0.001), trunk flexion (P = 0.01), and GMed muscle activity (P = 0.03). There were no significant differences in the activity of the rectus femoris and semitendinosus muscles, and ankle dorsiflexion (P > 0.05). Conclusions Poor lumbopelvic control affects the kinematics and activity of the lower limb muscles, and may be a risk factor for lower limb injuries, especially of the knee.

Differences in strength and landing biomechanics between female jumpers and swimmers

BACKGROUND: It remains unclear if plyometric training as a single component could improve landing mechanics that are potentially associated with lower risk of ACL injury in the long term OBJECTIVE: The purpose of this study was to investigate the influence of experience undertaking plyometrics on landing biomechanics in female athletes. METHODS: Non-jumpers with little experience in plyometric training (12 female college swimmers) and jumpers with five years of experience in plyometric training (12 female college long jumpers and high jumpers) were recruited to participate in two testing sessions: an isokinetic muscle force test for the dominant leg at 120∘/s and a 40-cm drop landing test. An independent t test was applied to detect any significant effects between cohorts for selected muscle force, kinematic, kinetic, and electromyography variables. RESULTS: While female jumpers exhibited greater quadriceps eccentric strength (P= 0.013) and hamstring concentric strength (P= 0.023) during isokinetic testing than female swimmers, no significant differences were observed in kinematics, kinetics, and muscle activities during both drop landing and drop jumping. CONCLUSIONS: The results suggest that the female jumpers did not present any training-induced modification in landing mechanics regarding reducing injury risks compared with the swimmers. The current study revealed that plyometric training as a single component may not guarantee the development of low-risk landing mechanics for young female athletes.

CHANGE IN KNEE SEPARATION DISTANCE IN ADOLESCENT ATHLETES AFTER A 6-WEEK NEUROMUSCULAR TRAINING PROGRAM

Background: Existing neuromuscular injury prevention programs have relied principally on lower extremity strengthening, agility, cutting and landing technique to improve jump landing mechanics in order to prevent non-contact knee ligament injuries. Purpose: To determine whether a 6-week neuromuscular training program emphasizing core (back & hip) strengthening and dynamic balance exercises can significantly improve normalized knee separation distance (nKSD) during a standard counter-movement jump landing maneuver. Methods: Fourteen adolescent athletes (11 boys, 3 girls, ages 12-15) volunteered to undergo a 2 day/week, 6-week off-season training program. On the first day of training, the athletes underwent assessments that included 2 trials of a counter-movement jump from a 40cm platform. The tests were recorded using a video camera in the frontal plane. Using Dartfish motion analysis software, knee separation distance (KSD) was measured as the distance (cm) between the femoral condyles at the lowest point of the jump landing, and intertrochanteric distance (ITD) as the distance (cm) between the femoral trochanters. Normalized knee separation distance was computed as nKSD = KSD/ITD. The training program focused on three progressions; increasing difficulty of core strengthening exercises, balance exercises, and agility drills. One-hour training sessions were subdivided as follows; 5 min dynamic warm-up, 10 min stretching, 10 min body weight core exercises, 15 min balancing exercises, 10 min dumbbell core exercises, 15 minute agility drills, 5 min of rest/hydration breaks. The athletes repeated the counter-movement jump test at the end of the 6 weeks. Results: There was a significant improvement (t = 2.740, p = 0.017) in nKSD between post-test (0.789 + 0.372) and pre-test (0.683 + 0.323) Conclusion: A 6-week neuromuscular training program focused on core strengthening and balance significantly improved jump landing mechanics which may reduce the risk of knee ligament injury.

Effect of Lumbopelvic Control on Landing Mechanics and Lower Extremity Muscles’ Activities in Female Professional Athletes: Implications for Injury Prevention

Background: Lumbopelvic control has recently been associated with function, kinesiology, and limb loading. However, poor lumbopelvic control has not been studied as a risk factor for lower limb injury in sports with frequent jump landings. The present study aimed to investigate the effects of lumbopelvic control on landing mechanics and lower limb muscle activity in professional athletes with frequent landing.Methods: This study was conducted on 34 professional female athletes aged 18.29±3.29 years with the mean height and weight of 173.5±7.23 centimeters and 66.79±13.37 kilograms, respectively. The lumbopelvic control of the subjects was evaluated using the knee lift abdominal test, bent knee fall-out, active straight leg raising, and PRONE test by the pressure biofeedback unit. Based on the test results, the participants were equally divided into two groups of with and without lumbopelvic control (n=17). Landing mechanics were evaluated by an expert blinded to the procedures using the landing error scoring system (LESS) and two-dimensional video analysis. In addition, electrical muscle activity in single-legged standing skills was assessed via surface electromyography.Results: The results of independent samples t-test indicated significant differences between the groups with and without lumbopelvic control in terms of the LESS test scores (P=0.0001), lateral trunk flexion (P=0.0001), knee valgus (P=0.0001), knee flexion (P=0.001), trunk flexion (P=0.01), and gluteus medius muscle activity (P=0.03). However, no significant differences were observed in the activity of the rectus femoris and semitendinosus muscles, and ankle dorsiflexion (P>0.05).Conclusions: Poor lumbopelvic control affects the kinematics and electrical activity of the lower limb muscles and may be a risk factor for lower limb injuries, especially knee injury.