TUCK JUMP ASSESSMENT AS AN INDICATOR OF PREVIOUS UPPER EXTREMITY INJURY

Background: When using the tuck jump as a dynamic movement assessment, clinicians note movement flaws to determine injury potential and provide further training in attempt to improve movement technique deficits. The Tuck Jump Assessment has been identified as a dynamic assessment for lower extremity injury susceptibility.[3-6] The purpose of the Tuck Jump Assessment is to identify postural neuromuscular imbalances, throughout the dynamic movement, that could potentially result in greater injury susceptibility.[5] With the focus of neuromuscular imbalances on Tuck Jump Assessment performance, as well as the common notion of the body acting as a kinetic chain functions most efficient when there is proximal stability for distal mobility,[1] it was our purpose to determine if the Tuck Jump Assessment can be used as a dynamic movement assessment to ascertain a previous history of upper extremity injury in overhead throwing sports such as baseball and softball. We hypothesized that a more flexed trunk and less elevated upper leg in the peak of the tuck jump would correlate with previous history of upper extremity injury for the overhead athlete. Methods: Seventy-one youth baseball and softball athletes (28 baseball/43 softball; 12.41 ± 2.22 yrs.; 161.98 ± 13.65 cm; 59.17 ± 14.90 kg) were recruited to participate. All participants were in good physical condition and had no injuries within the last six months. A health history form was completed by the participants prior to participation. If a participant indicated that they have had an upper extremity injury in the past year that had kept them from competition, then they were placed in the previous injury group (N = 18). All other participants were placed into the no previous injury group (N = 53). Participants that indicated they had a previous lower extremity injury were excluded from of the study. The University’s Institutional Review Board approved all testing protocols. Informed written consent was obtained from each participant and participant’s parents before testing.[2] Kinematic data were collected at 100 Hz using an electromagnetic tracking system (trakSTARTM, Ascension Technologies, Inc., Burlington, VT, USA) synced with the MotionMonitor® (Innovative Sports Training, Chicago, IL. USA). Participants were instructed to start with their feet shoulder width apart and initiate the jump with a slight downward crouch while holding their arms in front of their chest. As they jumped, they were instructed to pull their knees as high as possible during the jump aiming to reach a position where their thighs were parallel to the ground and to immediately begin the next tuck jump once landing.[5] A trial of 10 tuck jumps was collected. Analysis included jumps 4 through 8 to mitigate the Hawthorne effect. Values for trunk flexion and upper leg elevation were taken from peak leg elevation and averaged and a priori was set at a level of p = 0.05 to determine significance. Results: A logistic regression showed no significance in trunk flexion or upper leg elevation being able to determine upper extremity injury (&[Chi] &[sup]2 (&[sub]1, N = 71) = 3.55, p = .315). The model explained 7.2% of the variance in upper extremity injury and correctly classified 73.2% of all cases. Conclusion/Significance: While a direct link was not found between the Tuck Jump Assessment and upper extremity injury, further investigation into injury precursors should be performed. During our Tuck Jump Assessment, we only examined trunk flexion and upper leg elevation, which are two variables that make up the proximal control factor indicated by Lininger and colleagues. [3] In their exploratory factor analysis, it was concluded that three factors defined as fatigue, distal landing pattern, and proximal control should be examined to get the most benefit of the Tuck Jump Assessment in injury assessments.[3] Our results agree with their conclusion, that a simplified unidimensional construct of the Tuck Jump Assessment may not be the best way to use this dynamic movement assessment to identify previous upper extremity injury. In conclusion, examining only trunk flexion and upper leg elevation during the Tuck Jump Assessment is not enough for clinicians to recognize previous upper extremity injury. Even though the body behaves as a kinetic chain, simplifying the dynamic movement assessment while not specifying the type of upper extremity injury is not favorable for the clinician to identify previous injury. References Chu SK et al. PM R. 2016;8(3 Suppl): S69-77. Harris D et al. Int J Sports Med. 2017;38:1126-1131. Lininger MR et al. J Strength Cond Res. 2017;31(3):653-659. Myer GD et al. Strength and Conditioning Journal. 2011;33(3):21-35. Myer GD et al. Athl Ther Today. 2008;13(5):39-44. Myer GD et al. Am J Sports Med. 2010;38(19):2025-2033.