Lower-Limb Sports Injuries in Breaststroke Swimming
By Dr. Yi-Cheng Wu · Reviewed June 21, 2026
Lower-limb breaststroke injuries are mostly chronic overuse problems. The most common are breaststroker's knee and groin muscle pain, both related to training volume, so treatment and training are key to preventing recurrence.
Lower-limb breaststroke injuries mostly build up from chronic overuse and rarely appear as an acute onset. The most common is breaststroker's knee, where inner-knee discomfort is linked to the medial collateral ligament or bursitis; patellofemoral pain syndrome and patellar tendinopathy are also possible, and over the long term the picture may be associated with chondromalacia. Another common problem is groin pain on the inner thigh, related to imbalance or strain from overuse of the iliopsoas, adductor group, and rectus abdominis, and it correlates positively with training volume. Most cases can be diagnosed through history, physical examination, X-ray, and ultrasound, after which treatment and training are key to preventing repeated episodes.
I recently saw a patient who had swum mostly breaststroke in the past and had developed knee pain. Breaststroker’s knee most often causes discomfort on the inner side of the knee, linked to the medial collateral ligament or bursitis, though patellofemoral pain syndrome and patellar tendinopathy are also possible. Over the long term it may lead to chondromalacia. The well-known Mayo Clinic in the United States has reported that among breaststroke swimmers with more than eight years of training, several were found to have chondromalacia.
Lower-limb sports injuries from breaststroke mostly build up gradually and are more related to overuse, rarely appearing as an acute onset. The likelihood tends to rise with age, and the associated discomfort often does not stop people from swimming, so many keep swimming through it. That also means the problem is frequently overlooked and can become a chronic, recurring symptom. For more on breaststroker’s knee, see the separate article Common swimming injuries: breaststroker’s knee.
Groin pain
Besides the knee, another sports injury more associated with breaststroke is pain around the inner thigh and groin. It relates to imbalance or strain from overuse of certain muscle groups and usually correlates positively with breaststroke training volume. The nearby muscles include the iliopsoas, the adductor group, and the rectus abdominis.
Adductor group
The main muscles are the adductor longus, adductor brevis, and adductor magnus. These are used in the propulsion phase, when at the moment the thighs squeeze together, the adductor group must contract to complete the leg-squeezing action.
Iliopsoas
The iliopsoas includes the iliacus and the psoas major. Its main functions are to control anterior and posterior tilt of the pelvis and to flex the hip, which helps stabilize the body’s core and pelvis. Everyday life and walking both need the assistance of the iliopsoas, and in office workers who sit for long periods and rarely exercise, the iliopsoas can become relatively weak.
During swimming, it is the muscle used in the recovery phase and the leg-tucking action of breaststroke. In the recovery phase, if core or gluteal strength is insufficient, the iliopsoas needs to assist more in order to complete the movement.
Rectus abdominis
The rectus abdominis can contribute to groin pain because its attachment point is on the pelvis. It provides an important stabilizing force for the pelvis and body throughout the breaststroke stroke.
Another less common situation is pain around the pubic symphysis (pubic bone overload, osteitis pubis), an inflammatory pain around the pubic symphysis caused by excessive stress, possibly related to stress from surrounding muscle imbalance.
How to prevent it
Although there is not yet enough research to prove that lower-limb breaststroke injuries can be reduced, a few principles still serve as useful references.
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Adequate warm-up: less warm-up is associated with a higher chance of injury.
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Resistance training: it can build core strength and muscle strength, and correct resistance training can strengthen the muscles around the knee and hip.
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Correct stretching and training: adequate joint range of motion is very important for swimming, but stretching sometimes involves more than a single joint and needs to draw on ideas such as fascia and the regional interdependence hypothesis. Sometimes good stretching and training does not start from the knee that feels stuck, but from the hip.
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Appropriate treatment: no single treatment is absolutely right. Offering a suitable plan based on the patient’s history, injury status, current life and work, and even future goals — including rehabilitation, injections, and a training program — is the kind of care that truly helps. What treatment is suitable depends on your condition and a physician’s assessment.
Summary
Lower-limb sports injuries from breaststroke involve the knee and hip, and a few people even have ankle problems. They are related to chronic, cumulative injury and can mostly be diagnosed through history, physical examination, X-ray, and ultrasound. What matters, though, is the follow-up treatment and training that prevent repeated episodes.
Further reading
Common swimming injuries: breaststroker’s knee
Common muscle groups in the four swimming strokes
References
Musculoskeletal Injuries in Competitive Swimmers. Mayo clinic. JEFFREY E. JOHNSON, M.D
Frequency, associated factors, and treatment of breaststroker’s knee in competitive swimmers. Am J Sports Med. Mar-Apr 1985;13(2):99-104.
Hip adductor injury in competitive swimmers. Am J Sports Med. Jan-Feb 2004;32(1):104-8.
Image source: https://www.swimmind.com/breaststroke-kicking/
Further reading
Frequently asked questions
Why does breaststroke cause groin pain?
Besides the knee, pain around the inner thigh and groin is also more associated with breaststroke. It relates to imbalance or strain from overuse of certain muscle groups and usually correlates positively with breaststroke training volume. The muscles involved include the iliopsoas, the adductor group, and the rectus abdominis.
What role does the adductor group play in breaststroke?
The adductor group includes the adductor longus, adductor brevis, and adductor magnus, and these are the muscles used in the propulsion phase. At the moment the thighs squeeze together, the adductor group must contract to complete the leg-squeezing action, and overuse may be linked to groin pain.
How is the iliopsoas related to breaststroke?
The iliopsoas includes the iliacus and the psoas major. It mainly controls anterior and posterior tilt of the pelvis, flexes the hip, and stabilizes the core. It is used during the recovery phase and the leg-tucking action of breaststroke; if core or gluteal strength is insufficient, the iliopsoas needs to assist more and is more prone to overuse.
How does the rectus abdominis affect groin pain?
The rectus abdominis attaches to the pelvis and provides an important stabilizing force for the pelvis and body throughout the breaststroke stroke. Because it attaches to the pelvis, overuse may cause pain around the groin.
How can the risk of lower-limb breaststroke injuries be reduced?
Current research is not yet enough to prove that lower-limb breaststroke injuries can be reduced, but a few reference principles help: an adequate warm-up, resistance training that strengthens the muscles around the knee and hip, correct stretching and training (which sometimes needs to start from the hip rather than the knee), and a management plan tailored to the individual situation.
This article is also available in the original Chinese, with the full reference list.
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