Jumper’s Knee

We take this opportunity to have Dr. Kevin McIntyre of Burlington Sports Therapy introduce Jumper’s Knee.

Jumpers knee is a common term used to describe an overuse injury to the patellar tendon.  The technical term for this tendon injury is patellar tendinosis or patellar tendinopathy and is estimated to affect 45% of elite volleyball players.

So how do we apply our newest understandings of “Jumper’s Knee” to the athlete at risk? If a coach or trainer notices any of the above findings in one of their athletes they should be urged to try a soft landing technique, bending both the ankles and knees as much as possible to absorb the force of landing. If symptoms are present, frequency and intensity of jumping may need to be reduced. Supporting the patellar tendon with a brace to help alleviate pain. Of course, we always recommended that you consult with a doctor so that your condition can be diagnosed prior to any treatment.

According to the most current literature, patellar tendinosis is largely due to the eccentric load placed on the patellar tendon. That is, the tendon is lengthened under load when lowering for a jump and when bending the knee upon landing. (For an explanation of “eccentric contraction” please refer to our previous post about the prevention of hamstring strain). According to a study published in the British Journal of Sports Medicine, athletes who experienced patellar tendinosis had a tendency to land with a lesser degree of ankle and knee joint flexion on initial impact. That is, they didn’t bend their knees or ankles during landing to the extent of other athletes. The study also found that the rate at which the knee is forced into flexion upon landing may be a risk factor in the development of patellar tendinopathy.

ACL Injury Prevention

Here’s a great article we found on ACL Injury Prevention from Dr. Kevin McIntyre of Burlington Sports Therapy.  What makes this article great is it concisely describes common causes of ACL injuries, who is most likely to suffer from an ACL injury, and tips to prevent an ACL injury.

Last June we posted an entry on the prevention of anterior cruciate ligament (ACL) injuries. In that article, we learned that muscular co-contraction was very helpful in preventing an acute tear of this ligament. Today’s blog is going to review some of the more current understandings in sports medicine with respect to ACL injury and prevention, including some practical ways that coaches, parents and players can help identify those athletes at risk.

Most ACL injuries are non-contact, occurring during deceleration, landing or pivoting. In soccer, 58% of injuries are non-contact.  Athletes who run and change direction in a more upright position are at more risk of ACL injury.

Females are 4 to 6 times more likely to injure their ACL (some of the points below will help to explain this difference).  Hormonal changes have been shown to influence ligaments (like the ACL).  Such hormonal changes occur during monthly cycles and growth spurts.

Having “loose” joints can predispose you to ACL injury. For example, a positive measure of knee hyperextension increases the odds of anterior cruciate ligament injury status five-fold.  Greater knee laxity and increased general joint laxity are more prevalent in girls.  As boys get older there is a trend toward decreased joint flexibility and ligament laxity. Relative to boys, girls show more joint flexibility and ligament laxity with age.

A trend toward knee valgus (pictured below) has been well established in the literature as a risk factor of ACL injury.  Females tend to land from jumping in a more valgus position than males.  They also tend to land harder, suggesting less muscular recruitment and thereby less stabilization of the knee.

Prevention of ACL injuries would significantly reduce the chances of arthritis in adulthood. There is an estimated ten fold increase (incidence) after ligament injury.

Active and passive flexibility training may be contraindicated for preventing ACL injuries. Flexibility training does not provide protective effects from injury as has been previously reported in the literature.

Prevention works.  According to a recent study of 1435 female varsity soccer players, those who did the proper preventative exercises showed a 3 fold reduction in non-contact ACL tears.  There is a growing body of research validating ACL prevention programs.

Prevent ACL Knee Injuries
Prevent ACL Knee Injuries


Protect knees from sports injuries

In an article on CNN’s website, Dr. Melina Jampolis, a physician nutrition specialist, offers some great advice on how athletes can protect their knees from sports injuries.  The preventative technique she recommends focuses on teaching athletes improved awareness of injury risk as well as promoting proper motion patterns and muscle strengthening to minimize injury.  This program is called the HarmoKnee Preventative Training program and she summarizes the program as follows –

1. Warm-up: This phase involves jogging, backward jogging on the toes, high-knee skipping and two zigzagging and sliding exercises.

2. Muscle activation: This phase involves four-second contractions of major muscle groups in the lower body, including calves, quadriceps, hamstrings, hip flexors, groin, and hip and lower back muscles to help athletes increase awareness of individual muscle groups.

3. Balance: These exercises, which require careful form — including straight-line hip-knee-foot posture, shoulder-width apart, controlled landing on flexed knees, maintaining a low center of gravity, contraction of stomach and buttocks — should be performed slowly. They include backward and forward, single- and double-leg jumps lasting approximately 30 seconds each.

4. Strength: This phase, which requires similar form to the balance phase, including walking lunges, hamstring curls and single-knee squats with toes raised.

5. Core stability: The final phase also encourages proper form and includes sit-ups, plank on elbows and toes, and bridging (an exercise where your hips are lifted toward the ceiling and the position is held).

Dr. Jampolis notes this summary is just an outline that includes key components of a comprehensive knee injury prevention program and recommends you work with a coach or personal trainer to develop a similar program that works for you.

Click here to read Dr. Jampolis’ complete article on protecting knees from sports injuries.

Can foot orthotics relieve knee pain?

Foot orthoses provide knee pain relief in study

Prefabricated foot orthoses are superior to flat inserts in the short-term improvement of patellofemoral pain, according to a randomized clinical trial conducted at the University of Queensland’s School of Rehabilitation and Health Sciences in Brisbane, Australia. The study was published in the British Medical Journal.1

The four study test groups included those using Vasyli Medical foot orthoses, those wearing the flat inserts (placebo), those undergoing multimodal physiotherapy, and those using a combination of physiotherapy and foot orthoses. Participating in the study were 179 subjects, aged 18 to 40, who had clinical diagnoses of patellofemoral pain.

Subjects were evaluated over a 52-week period and all groups showed long-term improvement in patellofemoral pain management with no significant differences. At six weeks, the group using the Vasyli Medical foot orthoses experienced superior levels of knee pain relief when compared with the placebo group using flat inserts.

Think you might benefit from orthotics?  Shop our selection of  Foot Care products

Foot orthoses and physiotherapy in the treatment of patellofemoral pain syndrome: randomised clinical trial
Natalie Collins, PhD candidate,1 Kay Crossley, principal research fellow,2 Elaine Beller, director, biostatistics,3 Ross Darnell, statistician,1 Thomas McPoil, regents professor,4 and Bill Vicenzino, head of division, physiotherapy1