Volleyball blocking and hitting, how can I protect my knees from ACL injury?
Volleyball… what a sport, am I right? When played well (and let’s not sugarcoat it, “well” may not always be a fully accurate description of my performance) it is an elegant, fast paced and hard hitting sport that is deservedly one of the world's most popular.
Perhaps surprisingly for a non-contact spot, volleyball players are remarkably vulnerable to injury. Low back injuries, traumas to wrists, ankle sprains and shoulder dysfunctions are all common, not to mention bruised egos for good measure after the odd facial spike. In volleyball players though, knee injuries are the most common by a healthy margin.
Knee injuries come in various shapes and flavors, many of which are irritating but minor. Ligament tears though are not so minor. Anterior Cruciate Ligament (ACL) tears are serious concern for volleyball players, and are particularly related to landing technique when jumping. Ligaments connect bones to other bones in an effort to keep them from flying apart, which is useful. The ACL is an important one of these - it’s job centers around preventing the shin from shearing forward on the thigh. It’s the ligament that acts as a brake on kicking motions. Think of it as the structure preventing hyperextension.
Fig 1 - The ACL, a ligament in the knee that prevents hyperextension, kneecap is removed.
As mentioned above, at issue with ACL health and volleyball is the stress to that ligament when landing from a jump. The tendency when landing with poor technique is to collapse into a valgus position. This position is characterised by an in-kink and rotation at the knee as shown below.
Believe it or not Valgus positioning is mediated by poor strength and a lack of control in the muscles that control the hip as much as (or more than!) at the knee. Attention to physical training here will help to improve jump performance and reduce injury risk. More on that below.
Fig. 2 - Landing from a jump with valgus positioning. In the real example shown here, notice the inward kink shown on the left versus the knee-over-foot alignment on the right in the images of me
Volleyball is a jumping sport (obviously I hope!), so the knee is vulnerable because of this action. Additionally there are a number of risk factors associated with increased risk on jumping.
- Single leg landing technique: In general, landing on one leg is more problematic than landing on two. It’s easy to appreciate how bearing the load of your full body weight on landing is more stressful when borne on one leg versus two.
Fig 3 - Single leg landing technique is riskier for valgus position and ACL injury
This is not to say that you can never land single legged. That would be an unreasonable demand for a volleyball player. In fact certain blocking maneuvers, as well as most hitting from power or the back court require a single leg landing technique. Still being mindful of technique and landing 2 legged when most appropriate is a useful activity modification.
In my own experience I have managed knee pain in the past by controlling the temptation to land single legged after a one handed reach when blocking from the middle. Check yourself to see what your own technique is and modify as appropriate.
- Lateral movement blocking: Middle blockers have it hard. Executing a straight up and down vertical block from the middle should allow for the most part a simple 2 leg landing technique. But middle blockers frequently exercise a quick lateral movement and/or jump with lateral movement when shifting to block a hit from power or offside. These lateral movement/jump combos are riskier for ACL injury.
- Landing followed by immediate cutting movement: Similarly, executing a cutting motion immediately on landing from a jump as might be required to reposition for a hit after blocking, or for another block attempt put the athlete at risk for dropping into that dreaded valgus position and potential ACL injury
fig 4 - Lateral movement block above and Landing followed by immediate cut below.
So if we undertand the jumping scenarios that are riskier for ACL injury, and further why they are risky, what can we do to reduce that risk? As you might expect, strength training and motor control are two considerations that are very relevant relevant here.
Volleyball is a jumping sport that rewards strength and power. Maximising performance and minimising injury risk involves training both of these off the court so that we are a healthy rock star on it. See the video above for a description of some motor control and power exercises that will help to train both the strength/power of your jump and your ability to execute the motion beautifully!
Consider these exercises as part of your regular workout:
Motor Control (technique and some power) training: These are some exercises that help you to train the "skill" of the jumping (and especially landing) pattern. As I describe in the video, you can uses these exercises as an alternative warmup to the treadmill, elliptical or other cardio equipment.
- Ankle jumps: Raise your arms overhead as if in a blocking position. Perform skipping height jumps as if you are jumping rope. Execute for 30 seconds. 2-5 sets.
- Bounding in place: Holding a spot on the ground, alternate jumping from one leg to the other straight up and down. Progressively increase height. Execute for 25 seconds. 2-5 sets.
- Mattress Jumps: Take a mat (or an old mattress, I’m sure you have those laying around right?) and perform 2 footed jumps. Front-to-back and side-to-side. You may choose to pace a small barrier (small hurdle or a shot cone) to jump over and impress all your friends and coworkers. Execute for 20-30 seconds each direction. 2-5 sets.
- Squat jump: with arms in overhead as if in blocking position, perform a maximal vertical jump, landing in a squat position and touching hands to the floor. Perform 3 reps. 2-5 sets.
- Step/box jump: Find a 6-8 inch step or box (sturdy enough to jump onto). Start by standing in front of the step. Hop up and onto the step followed by an immediate hop off and execute a subsequent maximal vertical jump. So there are two hops and a maximal vertical jump in one repetition of this exercise. Execute 3 reps. 2-5 sets.
- Single leg broad jump: starting standing on one leg, execute a maximal jump forward landing on one leg. You must stick the landing for a repetition to count. Execute 3 reps. 2-5 sets.
Another consideration for your ttraditional strength training - Both squats and the deadlift should be the foundational exercies of your lower extremity strength training. Include them both in your workout. Remember that while both of these exercises are excellent lower body strength training movements, they are are also different and complementary patterns that bias opposing muscle groups.
Squats tend to be quadriceps and glutes dominant, while deadlifts tend to be hamstrings dominant. Almost all other lower body strength training exercises you’ll see are variants on one of these two basics! Think about lunges, stepups or tandem stance dips, they are all variations on the squat - while rack pulls and kettlebell swings are both variants on a deadlift.
I have discussed these two exercises in detail in my free eBook, The Foundational Movements available for download on my website at yorkvillephysiotherapy.com.
Practice the exercises described in this article and video as part of your regular workout. In sport there is no guaranteed protection against injury but there are positive things you can do to improve performance and minimise risk. Enjoy the exercise and form considerations presented here!
Further reading (if you really want to impress your friends)
Hewett, T. E., Stroupe, A. L., Nance, T. A., & Noyes, F. R. (1996). Plyometric training in female athletes: decreased impact forces and increased hamstring torques. The American journal of sports medicine, 24(6), 765-773.
Lobietti, R., Coleman, S., Pizzichillo, E., & Merni, F. (2010). Landing techniques in volleyball. Journal of Sports Sciences, 28(13), 1469-1476.
Noyes, F. R., Barber-Westin, S. D., Smith, S. T., & Campbell, T. (2011). A training program to improve neuromuscular indices in female high school volleyball players. The Journal of Strength & Conditioning Research, 25(8), 2151-2160.
Sole, C. J., Kavanaugh, A. A., & Stone, M. H. (2017). Injuries in Collegiate Women’s Volleyball: A Four-Year Retrospective Analysis. Sports, 5(2), 26.
Yeow, C. H., Lee, P. V. S., & Goh, J. C. H. (2011). An investigation of lower extremity energy dissipation strategies during single-leg and double-leg landing based on sagittal and frontal plane biomechanics. Human movement science, 30(3), 624-635.
Zahradnik, D., Jandacka, D., Holcapek, M., Farana, R., Uchytil, J., & Hamill, J. (2018). Blocking landing techniques in volleyball and the possible association with anterior cruciate ligament injury. Journal of sports sciences, 36(8), 955-961.