Many of our members at CrossFit Leyland compete in CrossFit and other sports such as netball, hockey, football and rugby. The latter sports in particular, can place a huge amount of stress on the knee joints, due to repeated cutting (changing direction at speed), turning, acceleration / deceleration, jumping and landing.
CrossFit on the other hand, predominantly takes place in the sagittal plane (up and down movements of flexion / extension), with little rotation, or change of direction with the exception of certain events at the CrossFit Games (pictured).
Therefore, in CrossFit the biggest risk of knee injury occurs in jumping, or more specifically the landing / rebounding phase of the jump.
If there is a lack of mobility, stability and strength around the ankles, knees and hips, then the risk of injury upon landing, or rebounding is much greater. Individuals at the greatest risk are those who have not developed foundational stability /strength (i.e. beginners), or those who have lost these attributes (i.e. athletes returning from injury, following an extended period of not training). It is advisable for these individuals to scale high impact movements (e.g. Box jumps > single jumps with no bounding / air squats / step ups).
Female athletes are also more susceptible to knee injuries due to the Q-angle of the hips (the angle at which the upper leg, meets the lower leg). This biomechanical gender difference (amongst other factors) puts females at a greater risk of knee injury, particularly when landing / rebounding, or changing direction.
The following injury reduction strategies can help reduce the risk of non-contact knee injuries and would be useful for all athletes, but especially those in the high risk categories mentioned above;
- Ankle, knee, hip mobility
- Balance + stability exercises
- Lower body strength development exercises
- Landing mechanics drills
- Low level (basic) plyometric exercises
Take home message:
- Beginners, female athletes and athletes returning from injury are more susceptible to knee injuries when performing dynamic / explosive movements.
- Spend time developing stability and strength in a given movement pattern before power and endurance.
- Take caution with jumps / landings from large heights, particularly when fatigued.
- Consider stepping down, rather than bounding on high box jumps.
Useful links…..
Female Athletes – Biomechanics
https://www.verywell.com/q-angle-and-injuries-in-women-athletes-3120841
Female Athletes – ACL Injury Analysis
http://www.momsteam.com/health-safety/muscles-joints-bones/knee/acl-injuries-in-female-athletes
Mobility, Stability, Strength
http://www.fix-knee-pain.com/knee-strengthening-exercises/
Landing Mechanics
https://www.verywell.com/how-to-safely-land-a-jump-3119996
Plyometrics – Select the right level!
http://www.sport-fitness-advisor.com/plyometricexercises.html