Swimmer’s Guide to Knee Pain in Swimming

Knee pain in swimming is the third most common injured area. Rovere (1985) noted 87% of swimmers examined had a history of at least one episode of knee pain. PFPS isn’t the only condition which can occur at the knee for breaststroke swimmers, but is the most common from my experience.

Patellofemoral pain syndrome (PFPS) affects the kneecap and surrounding area. PFPS has a broad scope: it is a “condition of conditions,” with many possible variations and causes. In many cases, a more specific diagnosis is possible, but it’s considered PFPS if a more specific diagnosis cannot be found.

This condition is patellofemoral pain syndrome and the textbook definition is:

“Patellofemoral pain syndrome (PFPS) is a syndrome characterized by pain or discomfort seemingly originating from the contact of the posterior surface of the patella (back of the kneecap) with the femur (thigh bone). It is a frequently encountered diagnosis in sports medicine clinics.”

If you are unsure if you fit PFPS, here are some questions to ask:

• Is your pain somewhere around the kneecap?
• Is pain worse when going up stairs or hills?
• Does deep knee flexion bother the knee?
• Does your knee hurt during the outsweep of the breaststroke kick?
• Does your pain occur when sitting with the knee bent and hurt worse when you get up?

These aren’t the only questions for ruling in PFPS, but help narrow down the likelihood.

Why do Swimmers get PFPS

Clearly breaststroke is an awkward position at the knee. This motion puts stress at the knee, specifically the medial compartment. Stulberg (1980) noted breaststroke swimmers had evidence of patellofemoral osteoarthritis. Keskinen (1980) concluded:

“a combination of high angular velocities at the hip and knee and external rotation of the tibia relative to the femur repeated in excessive amounts might be the primary cause for the medial synovitis documented in these patients. The breaststroker’s knee thus seems to be an overuse syndrome”.

These older studies are some of the only research on the subject. New research in this field is required, but that takes time and funding.

Fixing PFPS in Swimmers

Helping PFPS in swimmers is a multifactorial approach. This approach requires focus on strength, length, and timing (for elite athletes, this means motor control and biomechanics).

Common muscles with altered position

Impaired tissue quality or tissue length is common in the muscles below. These muscles can also inhibit strength of the gluteal muscles (see below). From my experience, improving the tissue quality of the muscles below is paramount for recovery. Improving these is possible with self-myofascial releases (SMR) or working with a skilled manual therapist.

Commonly Weak Muscles

The gluteal muscles are commonly weak or inhibited in those with PFPS. In swimming, if the glutes can not control the internal rotation at the knee, then the thighs will separate and increase stress at the medial knee.

Impaired Biomechanics

Swimmers often use too much hip abduction, increasing the distance of the leg from the body and the amount of torque at the knee joint. The further the foot is from the body, the more stress and increased injury risk. Coaches should instruct a narrow thigh position, with a maximal internal rotation allowing high force production with the feet, while minimizing the stress at the knee.

Although kinematic film analyses did not demonstrate statistical differences between cases and controls, dramatic differences in the injury rate were noted when hip abduction angles at kick initiation were less than 37 degrees or greater than 42 degrees (Vizsolyi 1987).

Often swimmers with PFPS and knee pain in swimming is from a lack hip internal rotation or simply don’t know how to use it. To test, have your swimmer lie on their stomach and sweep their feet out. This simple video demonstrates the range of motion for the kick. If they have enough range of motion, perhaps they are simply not capable of performing this movement with resistance or able to coordinate the body.

Another test is to have have them perform this motion with added resistance. This is a great initial stress test for re-checking the symptoms after any treatment, but also identifies weak swimmers, unable to perform this motion in the water.

Prevention

Looking for a bulletproof knee program, then an individualized dry-land which frequently monitors your hip strength, range of motion, soreness/pains, and biomechanics is mandatory. Also, gradually increasing breaststroke volume at the beginning of the season is also prevent overloading the tissue.

Summary

Improve your muscle length, strength, and timing for improvement of your PFPS in swimming. If you are looking for a prevention program, frequent monitoring and screening for individual risk factors is most effective. If these tools aren’t available, consider using the rehabilitation principles, but realize they may not be necessary.

Having Knee Pain in Swimming?

References

1. Vizsolyi P, Taunton J, Robertson G, Filsinger L, Shannon HS, Whittingham D, Gleave M.Breaststroker’s knee. An analysis of epidemiological and biomechanical factors. Am J Sports Med. 1987 Jan-Feb;15(1):63-71.
2. Rovere GD, Nichols AW. Frequency, associated factors, and treatment of breaststroker’s knee in competitive swimmers. Am J Sports Med. 1985 Mar-Apr;13(2):99-104.
3. Keskinen K, Eriksson E, Komi P. Breaststroke swimmer’s knee. A biomechanical and arthroscopic study. Am J Sports Med. 1980 Jul-Aug;8(4):228-31.
4. Stulberg SD, Shulman K, Stuart S, Culp P. Breaststroker’s knee: pathology, etiology, and treatment. Am J Sports Med. 1980 May-Jun;8(3):164-71.

Written by Dr. John Mullen, DPT, CSCS.

Originally published January 2012.