Knee Valgus on the Volleyball Court

Observed faults: Jordan lands with dynamic knee valgus-the knees move inward while the hips adduct and internally rotate-and with a heel-first landing and a relatively upright, stiff trunk.

Why valgus matters: In the frontal plane, knee valgus increases the knee abduction moment and stress on the anterior cruciate ligament, especially when the knee is near extension at contact. It also increases patellofemoral joint stress and places more demand on the hip abductors and external rotators to control the femur. A player with prior ankle sprains may rely less on the ankle strategy and more on the knee, which can worsen this pattern.

Why heel-first matters: A heel-first landing with limited ankle dorsiflexion and knee flexion reduces the time and joint excursion available to absorb force. Landing forces in volleyball jumps can reach several times body weight. A midfoot or forefoot contact followed by controlled heel lowering lets the calf and Achilles tendon absorb eccentric load before the knee and hip flex. A stiff, extended landing increases the rate of force development and the load transferred to the knee.

What to screen: Observe a single-leg squat, ankle dorsiflexion, hip abduction control, and a drop landing from a 12-inch box. Do not diagnose an injury; use the screen to decide whether Jordan is ready for plyometric progression and whether referral to the athletic trainer is warranted.

Proceed, but not as proposed. A 15-minute plyometric block three days per week before practice is too much volume and intensity for beginners in a short preseason, especially with depth drops and no mats under the net. Plyometrics can be useful for landing mechanics and injury reduction, but only with controlled technique and volume.

Modified progression:

• Weeks 1–2: Two sessions per week, not three. Use 40–60 ground contacts per session: pogo hops, snap-downs from a 12-inch box, lateral step-and-stick, and low lateral bounds. No depth jumps from boxes higher than about 18 inches, and no box jumps to fatigue.
• Placement: After a dynamic warm-up and before technical practice, not after fatiguing drills. Stop the block if landings become sloppy.
• Work-to-rest: Keep repetitions short with about 1:5 work-to-rest so quality stays high. Use mats under the net and proper shoes.
• Progression: Increase to about 80 contacts by week 3 only if Jordan and teammates can stick landings with knees over toes for two seconds. Add box height before adding volume.

Address the parent’s concern: A growth spurt is not an automatic contraindication, but it is a reason to avoid heavy loads, high depth jumps, and high volume. Coordinate with the athletic trainer and monitor for pain. If Jordan cannot control valgus after two weeks, refer for screening rather than pushing intensity.

Cues: Use external-focus cues that direct attention to the outcome: ‘land quietly,’ ‘spread the floor,’ or ‘freeze like a statue for two seconds.’ Avoid a negated internal cue such as ‘don’t let your knees cave,’ which often increases the very motion it names. Cue one thing at a time: first quiet landings, then knees over toes, then stick the landing.

Low-tech assessment: Use a live landing-error checklist modeled on common screening items: knee valgus, trunk flexion, stance width, foot position at contact, and amount of knee flexion. Score five drop landings from a 12-inch box. Without video delay, have a peer observer use the checklist and give immediate feedback after each set, or use a smartphone to record and review after class if school policy allows. Do not rely on memory alone; record the scores.

Decision rule: Do not increase box height until the athlete shows at least four clean landings out of five with a two-second hold. If valgus persists despite cues, reduce box height, reduce volume, and refer to the athletic trainer. The goal is not to make the athletes sore; it is to change the landing strategy under controlled conditions.