HOME HELP CONTACT US SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:
Sign In to gain access to subscriptions and/or personal tools.

This Article Full Text Full Text (PDF) All Versions of this Article: 33/2/197    most recent 0363546504266484v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Request Reprints Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (8) Citing Articles via Google Scholar Google Scholar Articles by Noyes, F. R. Articles by West, J. Search for Related Content PubMed PubMed Citation Articles by Noyes, F. R. Articles by West, J. Related Collections Kinematics and kinetics Female Athletes Knee

The Drop-Jump Screening Test

Difference in Lower Limb Control By Gender and Effect of Neuromuscular Training in Female Athletes

From the Cincinnati Sportsmedicine Research and Education Foundation, Cincinnati, Ohio

^* Address correspondence to Sue D. Barber-Westin, 2146 Hidden Links Drive, Fort Myers, FL 33913 (e-mail: sbwestin{at}csmref.org).

Background: A valgus lower limb alignment has been noted during noncontact anterior cruciate ligament injuries. A video drop-jump test can indicate an athlete’s ability to control lower limb axial alignment in the coronal plane.

Hypotheses: Female athletes have decreased knee separation distances on landing and acceleration; male athletes have a neutrally aligned lower limb position. A neuromuscular training program will significantly increase knee separation distance in female athletes.

Study Design: Cohort study; Level of evidence, 2.

Methods: The authors tested 325 female and 130 male athletes aged 11 to 19 years. The distance between the hips, knees, and ankles was measured during a drop-jump test. The separation distance between the knees and ankles was normalized by the hip separation distance. A neuromuscular training program (Sportsmetrics) was completed by 62 female athletes, and their jump-landing characteristics were reexamined.

Results: A marked decrease in knee separation distance was found on takeoff in 80% of female athletes and in 72% of male athletes. There was no difference between male and female athletes in the normalized knee and ankle separation distance during the landing and takeoff phases. The knee separation distance on landing was 23 ± 9 cm in the female athletes and 22 ± 8 cm in the male athletes. The normalized knee separation distance was 51% ± 19% in the female athletes and 51% ± 15% in the male athletes. After training, statistically significant increases were found in the female athletes in the knee separation distance on landing (29 ± 8 cm, P < .0001) and in the normalized knee separation distance (68% ± 18%, P < .0001). The trained female athletes had significantly greater knee separation distance and normalized knee separation distance than did the males (P < .0001).

Conclusions: The majority of untrained female and male athletes demonstrated a valgus alignment appearance on the video test. After neuromuscular training, female athletes had improved knee separation distances and a more neutral lower limb alignment on landing and takeoff.

Key Words: video drop-jump test • lower limb alignment • neuromuscular training

This article has been cited by other articles:

				M. Liederbach, F. E. Dilgen, and D. J. Rose Incidence of Anterior Cruciate Ligament Injuries Among Elite Ballet and Modern Dancers: A 5-year Prospective Study Am. J. Sports Med., September 1, 2008; 36(9): 1779 - 1788. [Abstract] [Full Text] [PDF]

				M. Joseph, D. Tiberio, J. L. Baird, T. H. Trojian, J. M. Anderson, W. J. Kraemer, and C. M. Maresh Knee Valgus During Drop Jumps in National Collegiate Athletic Association Division I Female Athletes: The Effect of a Medial Post Am. J. Sports Med., February 1, 2008; 36(2): 285 - 289. [Abstract] [Full Text] [PDF]

				A. M. W. Chaudhari, T. N. Lindenfeld, T. P. Andriacchi, T. E. Hewett, J. Riccobene, G. D. Myer, and F. R. Noyes Knee and Hip Loading Patterns at Different Phases in the Menstrual Cycle: Implications for the Gender Difference in Anterior Cruciate Ligament Injury Rates Am. J. Sports Med., May 1, 2007; 35(5): 793 - 800. [Abstract] [Full Text] [PDF]

				T. Hewett, L. Snyder-Mackler, K. P. Spindler, F. R. Noyes, and S. D. Barber-Westin Letters to the Editor * Authors' Response Am. J. Sports Med., January 1, 2007; 35(1): 145 - 147. [Full Text] [PDF]

				R. P. Pfeiffer, K. G. Shea, D. Roberts, S. Grandstrand, and L. Bond Lack of Effect of a Knee Ligament Injury Prevention Program on the Incidence of Noncontact Anterior Cruciate Ligament Injury J. Bone Joint Surg. Am., August 1, 2006; 88(8): 1769 - 1774. [Abstract] [Full Text] [PDF]

				S. D. Barber-Westin, F. R. Noyes, and M. Galloway Jump-Land Characteristics and Muscle Strength Development in Young Athletes: A Gender Comparison of 1140 Athletes 9 to 17 Years of Age Am. J. Sports Med., March 1, 2006; 34(3): 375 - 384. [Abstract] [Full Text] [PDF]

				S. D. Barber-Westin, M. Galloway, F. R. Noyes, G. Corbett, and C. Walsh Assessment of Lower Limb Neuromuscular Control in Prepubescent Athletes Am. J. Sports Med., December 1, 2005; 33(12): 1853 - 1860. [Abstract] [Full Text] [PDF]