Swimmer’s Guide to Pain-Free Knees

If you’re experiencing knee pain while swimming and you’ve ruled out a knee injury, the root of that pain may be in another joint. This article addresses primarily breaststroke kick and freestyle kick, but the overall issues are similar in backstroke kick and butterfly kick.

Primary causes of knee pain

For many swimmers, the root of knee pain is often in the ankles or hips. Weakness or tightness in either the hips or ankles can result in increased stress on your knees as you kick. 

If you lack ankle flexibility in one or both ankles, your knees must work harder. Tightness in your hips can also increase stress on your knees.

Specifically, during breaststroke kick, tightness during hip flexion and internal rotation can force you to compensate with your knees.

It’s also possible to have weakness in the muscles around the quadriceps, which can lead to your knee fatiguing faster and becoming more susceptible to injury.

Exercises to help alleviate knee pain

For many swimmers, the key to eliminating knee pain while swimming is focusing on restoring a full range of motion in the hips and ankles and strengthening the muscles around the knees and hips.

For restoring ankle range of motion:

• Wall ankle dorsiflexion stretch. Do 2 sets of 15 reps on the tight ankle.
• Sitting on heels. Do 2 sets of 1–2 minutes. (Respect your knee pain and hold off on this stretch until you can bend your knees with no pain.)

For improving hip range of motion:

• Quadruped rock back. Do 2 sets of 10 reps.
• Kneeling hip-flexor stretch. Do 3 sets of 30 seconds each side.

For improving strength in the muscles around the hips and knees:

• Split squat. Do 3 sets of 12 reps.
• Single-leg hip bridge. Do 3 sets of 10 reps on each side.
• Side plank. Do 3 sets of 20–30 seconds each side.

Modifications in the pool

A too-wide breaststroke kick that’s powered by the knees increases stress on the inside of the knees. Focus on keeping your thighs closer together as you kick. This can be done by kicking a length or two with a pull buoy to bring your knees in.

Not only does this help reduce stress on your knee, but it also increases your ability to overcome drag as your legs aren’t as far outside of your bodyline. This should not be overdone as a too-narrow kick can cause a different type of knee pain.

During flutter kick, if you have limited ankle motion, you’re likely kicking from your knees instead of from your hips. Kicking from your knees isn’t as powerful as it doesn’t allow for maximum use of all the muscles around your hips and knees, and it causes you to bicycle and create more drag.

To help yourself to remember to kick from the hips, imagine you’re trying to kick a soccer ball as you kick. This helps reinforce using your hip to drive the kick while letting your knees and ankles naturally whip, as though a soccer ball is being launched from your toes at the end of your kick.

The common deficits associated with knee pain while swimming are limitations in ankle and hip mobility and weakness in the muscles around the knees and hips. Working on these areas can help you overcome and prevent knee pain.