PT  - JOURNAL ARTICLE
AU  - Rob W Bisseling
AU  - At L Hof
AU  - Steef W Bredeweg
AU  - Johannes Zwerver
AU  - Theo Mulder
TI  - Relationship between landing strategy and patellar tendinopathy in volleyball
AID  - 10.1136/bjsm.2006.032565
DP  - 2007 Jul 01
TA  - British Journal of Sports Medicine
PG  - e8--e8
VI  - 41
IP  - 7
4099  - http://bjsm.bmj.com/content/41/7/e8.short
4100  - http://bjsm.bmj.com/content/41/7/e8.full
SO  - Br J Sports Med2007 Jul 01; 41
AB  - Objective: The aetiology of patellar tendinopathy (jumper’s knee) remains unclear. To see whether landing strategy might be a risk factor for the development of this injury, this study examined whether landing dynamics from drop jumps differed among healthy volleyball players (CON) and volleyball players with a jumper’s knee. The patients with jumper’s knee were divided into an asymptomatic group with a previous jumper’s knee (PJK) and a symptomatic group with a recent jumper’s knee (RJK). Methods: Inverse dynamics analyses were used to estimate lower extremity joint dynamics from 30, 50 and 70 cm drop jumps in the three groups (CON, n = 8; PJK, n = 7; RJK, n = 9). A univariate repeated measures analysis of variance was used to compare the different landing techniques. Results: Data analysis of the landing dynamics revealed that PJK showed higher knee angular velocities (p<0.01), and higher ankle plantar flexion moment loading rate (p<0.01). Furthermore, strong tendencies of higher loading rate of vertical ground reaction force (p = 0.05) and higher knee extensor moment loading rate (p = 0.08) were found compared with CON. Higher values for peak knee moment, peak knee power and knee work (all p<0.01) were found for CON compared with RJK. The comparison of the two jumper’s knee groups yielded higher knee angular velocities (p<0.01), together with higher ankle plantar flexion and knee extensor moment loading rate (p<0.01 and p<0.05, respectively). Conclusion: Where RJK used a landing technique to avoid high patellar tendon loading, PJK used a stiffer landing strategy, which may be a risk factor in the development of patellar tendinopathy.