Risk of injury analysis in depth jump and squat jump

Introduction: The depth jump (DJ) and squat jump (SJ) are accepted ways to assess and train power producing ability but are not without risk of injury. Methods: Sixteen male participants (age = 21.7 ± 1.54 yrs., height = 177.7 ± 11.4 cm, mass = 77.7 ± 13.6 kg) were evaluated for power exertion capabilities while being assessed for risk of injury in the knee and low back through a range of resistances based on a percentage of participants’ heights in the DJ (0% through 50%) and bodyweights for the SJ (0% through 100%). Two variables were used to assess the risk of injury in the knee: valgus angle and internal abduction moment (IAM). Four variables were used in the low back: compression and shear force at the L5/S1 vertebrae, intra-abdominal pressure (IAP), and erector muscle tension. Results: With increasing DJ drop height, participants showed increased risk of injury in the knee through the valgus angle and IAM. In the low back, significant correlation occurred between increasing drop height and the shear force and IAP while compression force and erector muscle tension were more correlated with the power exertion of the participants than the drop height. With increasing SJ resistance, no significant increased risk of knee injury was detected. However, all low back variables except the IAP were significantly influenced by the increased resistance. Conclusion: Risk of injury in the knee and low back can be strongly dependent not only on the type of jump, but also the amount of resistance. The resulting power exerted by the athlete can also influence the risk of injury

Risk of injury analysis in depth jump and squat jump

Introduction: The depth jump (DJ) and squat jump (SJ) are accepted ways to assess and train power producing ability but are not without risk of injury. Methods: Sixteen male participants (age = 21.7 ± 1.54 yrs., height = 177.7 ± 11.4 cm, mass = 77.7 ± 13.6 kg) were evaluated for power exertion capabilities while being assessed for risk of injury in the knee and low back through a range of resistances based on a percentage of participants’ heights in the DJ (0% through 50%) and bodyweights for the SJ (0% through 100%). Two variables were used to assess the risk of injury in the knee: valgus angle and internal abduction moment (IAM). Four variables were used in the low back: compression and shear force at the L5/S1 vertebrae, intra-abdominal pressure (IAP), and erector muscle tension. Results: With increasing DJ drop height, participants showed increased risk of injury in the knee through the valgus angle and IAM. In the low back, significant correlation occurred between increasing drop height and the shear force and IAP while compression force and erector muscle tension were more correlated with the power exertion of the participants than the drop height. With increasing SJ resistance, no significant increased risk of knee injury was detected. However, all low back variables except the IAP were significantly influenced by the increased resistance. Conclusion: Risk of injury in the knee and low back can be strongly dependent not only on the type of jump, but also the amount of resistance. The resulting power exerted by the athlete can also influence the risk of injury

Comparison of Drop Jump and Resisted Squat Jump

Measuring maximum power an athlete can produce is key to developing proper strength and conditioning programs, assessing progress in injury recovery, and evaluating overall athleticism. A vertical jump action is a widely accepted way to assess power producing ability. Power production is dependent upon the force applied against resistance and the velocity of the movement. This resistance is in the form of drop height in a drop jump and external weight in a squat jump. The power can be observed either as the peak power produced at any instant during the movement or as the average power produced throughout a defined time period of the motion. In this investigation, subjects’ power producing abilities were tested in a drop jump and a squat jump through a range of levels of resistance. The resistances were based on percentage of the subjects’ individual anthropometric data set at 0-, 10-, 20-, 30-, 40-, and 50% of the subjects’ heights in the drop jump and 0-, 20-, 40-, 60-, 80-, and 100% of the subjects’ body weights for the squat jump. Objective #1 sought the optimal resistance level for both jumping movements in which maximum power production is possible. These movements are not without potential injury. Objective #2 assessed six variables through modeling to predict the risk of injury in the movements in the knees and lower back. The variables included the valgus angle and the corresponding internal abduction moment of the knee, the compression and shear forces at the L5/S1 vertebrae, the abdominal pressure, and the lower back muscle tension. The type of jump and the resistance level of the jumps proved to have an effect on the risk of injury. Objective #3 established a method to use the peak or average power obtained by one of the jumping movements at any resistance level to estimate the peak or average power at any resistance level in either jumping movement. This translation of performance assessment would allow an athlete to be assessed for power production in a preferred jumping movement to avoid the risk of injury, while predicting their power production in another movement

Comparison of Drop Jump and Resisted Squat Jump

Measuring maximum power an athlete can produce is key to developing proper strength and conditioning programs, assessing progress in injury recovery, and evaluating overall athleticism. A vertical jump action is a widely accepted way to assess power producing ability. Power production is dependent upon the force applied against resistance and the velocity of the movement. This resistance is in the form of drop height in a drop jump and external weight in a squat jump. The power can be observed either as the peak power produced at any instant during the movement or as the average power produced throughout a defined time period of the motion. In this investigation, subjects’ power producing abilities were tested in a drop jump and a squat jump through a range of levels of resistance. The resistances were based on percentage of the subjects’ individual anthropometric data set at 0-, 10-, 20-, 30-, 40-, and 50% of the subjects’ heights in the drop jump and 0-, 20-, 40-, 60-, 80-, and 100% of the subjects’ body weights for the squat jump. Objective #1 sought the optimal resistance level for both jumping movements in which maximum power production is possible. These movements are not without potential injury. Objective #2 assessed six variables through modeling to predict the risk of injury in the movements in the knees and lower back. The variables included the valgus angle and the corresponding internal abduction moment of the knee, the compression and shear forces at the L5/S1 vertebrae, the abdominal pressure, and the lower back muscle tension. The type of jump and the resistance level of the jumps proved to have an effect on the risk of injury. Objective #3 established a method to use the peak or average power obtained by one of the jumping movements at any resistance level to estimate the peak or average power at any resistance level in either jumping movement. This translation of performance assessment would allow an athlete to be assessed for power production in a preferred jumping movement to avoid the risk of injury, while predicting their power production in another movement

Optimal depth jump height quantified as percentage of athlete stature

Purpose: An individual’s optimal depth jump platform height provides a resistive force which allows an athlete to rebound with substantial velocity resulting in maximum power exertion. The objective of this investigation was to show that the optimal platform height in a depth jump can be quantified as a percentage of individual body stature which can serve as measurable quantified value. Although athlete height is not highly correlated to power ability nor does a universal height exist, this value can provide a basis for a rehabilitation or strength and conditioning program. The desired intensity of a program can be prescribed as a percentage of the individual’s optimal drop height. Methods: Sixteen male participants (age = 21.7 ± 1.54 yrs., height = 177.7 ± 11.4 cm, mass = 77.7 ± 13.6 kg; mean ± SD) were tested in a depth jump through a range of platform heights based on percentage of the individual anthropometric data defined at 0-, 10-, 20-, 30-, 40-, and 50% of the participants’ stature using a 3-D motion capture system (Qualysis) and force plates (Bertec) to calculate power. Results: The optimal drop height was found to be 21.3 (±10.3)% of the participants’ heights for maximum peak power and 27.5 (±15.3)% for maximum average power. Conclusions: These results suggest that an individual optimal drop height does exist as a percentage of stature and could be applied to a rehabilitation or power-based training program using the drop height as a quantified basis allowing an athlete to gradually work toward their individual optimal drop height and exhibit maximum power. Keywords: Kinematics; Kinetics; Lower extremity assessment; Plyometrics; Power

Frontal plane comparison between drop jump and vertical jump: Implications for the assessment of ACL risk of injury

The potential to use the vertical jump (VJ) to assess both athletic performance and risk of anterior cruciate ligament (ACL) injury could have widespread clinical implications since VJ is broadly used in high school, university, and professional sport settings. Although drop jump (DJ) and VJ observationally exhibit similar lower extremity mechanics, the extent to which VJ can also be used as screening tool for ACL injury risk has not been assessed. This study evaluated whether individuals exhibit similar knee joint frontal plane kinematic and kinetic patterns when performing VJs compared with DJs. Twenty-eight female collegiate athletes performed DJs and VJs. Paired t-tests indicated that peak knee valgus angles did not differ significantly between tasks (p = 0.419); however, peak knee internal adductor moments were significantly larger during the DJ vs. VJ (p \u3c 0.001). Pearson correlations between the DJ and VJ revealed strong correlations for knee valgus angles (r = 0.93, p \u3c 0.001) and for internal knee adductor moments (r = 0.82, p \u3c 0.001). Our results provide grounds for investigating whether frontal plane knee mechanics during VJ can predict ACL injuries and thus can be used as an effective tool for the assessment of risk of ACL injury in female athletes