Tendon injuries are common in athletes. Patellar tendonitis, also called “jumper’s knee,” is an overuse injury that causes pain at or near the kneecap (the patella). Medical professionals know that such factors as intense training, poor training techniques, or improper shoes can lead to patellar tendonitis. However, under the same conditions, some athletes develop patellar tendonitis and some don’t. These researchers wanted to find out if there were any differences between those two groups of athletes.
The researchers studied 138 physical education students in Belgium for two years. At the start of the study, the students underwent a series of tests to measure such physical characteristics as leg length and alignment, muscle tightness and strength, height, and weight. The students were examined every three months by a doctor and orthopedic surgeon. By the end of the study, 19 of the 138 students (about 14%) had developed patellar tendonitis.
The researchers then compared the measurements of the group who had developed patellar tendonitis with those who hadn’t. Both groups had taken part in the same types of sports for about the same amount of time. They also had similar results on all physical measurements–except one. The group who developed tendonitis tended to have less flexibility in their quadriceps and hamstring muscles at the beginning of the study.
This study involved only a small group of students. The authors caution that more research is needed to further understand what factors cause patellar tendonitis. They suggest that future studies focus on bigger groups and compare athletes within the same sport. But the authors also feel that stretching is in order for athletes who don’t have good flexibility in their hamstrings or quadriceps. Stretching could also be useful for athletes recovering from patellar tendonitis.