Knee Injuries Associated With Landing Mechanics In Volleyball Players
Who am I?
My name is Melisa Luong and I’m a Registered Physiotherapist at Honsberger Physio +. I’ve played competitive volleyball for over 10 years and recently started coaching a 14U girls’ team this past summer. I’ve treated, seen, and experienced first hand multiple incidents of injuries in volleyball from rotator cuff tears to ankle sprains. My years of experience as a player in combination with my educational background allows me to understand what it takes to bring your performance to another level. As a physiotherapist and coach, my goal is to help my athletes perform at their maximum potential and to increase the longevity of their athletic career.
Jumping and Volleyball
Volleyball is a dynamic, plyometric sport where athletes are required to jump repetitively whether it be to spike, serve, set, or block. Majority of the jumps involved in volleyball utilize two feet, but approximately half of the landings are on one foot. Most injuries that occur in volleyball are non-contact and occur during the jump-landing sequence. These landings create ground reaction forces up to five times the athlete’s body weight- is your body ready to handle this extra force?
There are three phases in the jump-landing sequence: load phase, flight phase, and landing phase. In the load phase, the athlete loads their joints in preparation for propulsion. This involves contraction and shortening of the hip flexor, knee flexor, and dorsi flexor muscles. In the flight phase, the athlete powerfully extends to propel themself into the air. This involves contraction and shortening of the hip extensor, knee extensor, and plantar flexor muscles. Lastly, in the landing phase, the athlete makes contact with the ground and aims to decelerate and absorb the impact from the jump. This involves contraction and lengthening of the hip extensor, knee extensor, and plantar flexor muscles. According to Newtonian mechanics, increases in jump height must be accompanied by a proportional increase in impact absorption to avoid injury.
What Can Go Wrong?
In numerous studies examining landing mechanics in relation to injury, ground reaction force was an objective measure used to determine risk of injury. A higher ground reaction force is associated with an increased risk of injury. It was found that minimal hip and knee flexion and ankle dorsiflexion during landing was associated with a higher ground reaction force.
ACL tears are a common injury in volleyball players. With the non-contact mechanism of injury of ACL tears, athletes are landing in a position with minimal hip and knee flexion, hip adduction and internal rotation, external rotation of the tibia relative to the femur, internal rotation of the tibia on the foot, and forefoot pronation. Lower knee angle is associated with higher shearing forces which puts the ACL ligament in a stretched position.
Patellar tendonitis or “jumper’s knee” is also a common injury in volleyball players. In a study evaluating performance measures in male and female volleyball players, it was found that athletes with less than 45 degrees of dorsiflexion were 1.8 to 2.8 times more likely to have an abnormal patellar tendon than those with more than 45 degrees of dorsiflexion. A decrease in dorsiflexion may increase the stress onto the patellar tendon during jumping activities which in turn can increase the risk of patellar tendon injury.
Biomechanical imbalances are often times caused by structural misalignment. 23% of the general population was found of have a leg length difference of 1cm or higher. The longer leg adopts the position of: forward rotated pelvis, knocked knee, and pronated foot – very similar to the non-contact mechanism for ACL tears! This position is also seen in both legs for individuals with overpronated feet. The shorter leg adopts the position of: bowed knee, supinated foot – which increases the risk of lateral ankle sprains. This pattern can also be caused by a functional misalignment where one pelvis shifts forward compared to the other creating the illiusion of one longer and one shorter leg. Functional misalignments can be a result of: poor posture, overuse of one side, or muscular imbalances.
One of the best ways to prevent knee injuries associated with the jump-landing sequence is by providing feedback. A recent volleyball-specific study demonstrated that after 2 minutes of verbal feedback, Division I female collegiate athletes were able to decrease their vertical ground reaction forces by 23% when landing from spiking a tossed volleyball. Video feedback is another way to provide feedback to athletes. This provides the athlete a visual of the biomechanical components of their jump-landing sequence and rewind or fast forward as needed.
Exercises are another way to prevent non-contact knee injuries in volleyball. Plyometrics training has been shown to reduce ground reaction force and decrease hip and knee abduction and adduction moments. Exercises should focus on both single and double leg landing for functional stability. Additionally, deceleration exercises targeting the hip extensors, knee extensors, and ankle plantar flexors will also aid in the dissipation of kinetic energy during the landing phase. Individual athletes and teams, especially those who are performing at a high level, are encouraged to incorporate these exercises in their physical conditioning programs to decrease risk the of injury. Examples of basic plyometric and eccentric strengthening exercises are demonstrated in the following video.
Screening exams conducted by your therapist can highlight any structural issues or muscle imbalances that may contribute to a higher risk of injury. As previously mentioned, biomechanical imbalances can be structural or functional. Identifying any alignment issues, strength deficits, or foot issues earlier on is imperative in preventing any or further injury. Once that has been established, you and your therapist can work together to create a training or rehab program to address any imbalances to optimize your performance.
Ensuring proper biomechanics in the jump-landing sequence is important in preventing non-contact injuries such as ACL tears and patellar tendonitis in volleyball players. This can be accomplished through providing verbal or video feedback, plyometric and eccentric strengthening exercises, and screening examinations conducted by your therapist. An ounce of prevention is worth a pound of cure! If you have any other questions regarding this topic, please feel free to send your inquiries to firstname.lastname@example.org.