pathology: swimmer’s knee / breast stroke swimmer’s knee

yogabook / pathologie / swimmer’s knee breast stroke swimmer’s knee

swimmer’s knee / breast stroke swimmer’s knee

Definition of

During breaststroke, the thighs are abducted below the frontal plane (this is what allows a wide abduction without exorotation in the hip joint ), combined with a reasonably clear flexion of the knee joint and (only then possible) exorotation of the lower leg in the knee joint. The propulsion is achieved by displacing the water during the subsequent adduction of the thighs, during which the knee joints are extended again, which forcibly cancels the exorotation of the lower leg. To the extent that the lifting of this exorotation is not undertaken consciously by the inner hamstrings but is left passively to the medial collateral ligament of the knee joint, the latter is subjected to repeated stress, particularly in the area of its distal insertion, which often leads to symptomatic overload symptoms during repeated training. This is all the more true because in this swimming style around 70% of the propulsion is generated by the legs. The introduction of the push straddle described above, which is common today, also shows the biomechanically difficult approach in the increase in the incidence of knee complaints compared to the straddle still common in competitive breaststroke before. 1990 in competitive breaststroke. Other swimming styles with leg movement in the sagittal plane therefore do not cause this type of disorder. This disorder is of course mainly due to the construction of the movement sequence.

However, the tendency to this disorder is also partly due to a muscle imbalance caused by the fact that the extensors of the knee joint, the quadriceps, are strengthened considerably more than the flexors, the hamstrings, as the adduction movement of the thighs, in which the knee joints are extended as quickly as possible, generates the main propulsion and therefore a lot of muscle power is used. In contrast, the abduction movement is performed at a more moderate speed, which strengthens the flexors less. Another aggravating factor is the water resistance plus the inertia of the lower leg, which causes valgus stress during the powerful adduction movement of the thighs, which also strains the medial collateral ligament. A final factor is the swinging exorotation movement of the lower leg in the knee joint itself, the acceleration of which is higher in breaststroke than in any other activity or sport. This movement is also significantly stopped by the medial collateral l igament.

Another source of disruption is the patella or femoropatellar sliding bearing, as the forceful extension of the knee joint is initiated from an exorotated position of the lower leg, which triggers a mainly two-dimensional patellar tilt: the exorotation of the lower leg rotates the tibial tuberosity laterally, which rotates the inferior patella laterally and tilts its lateral half dorsally. This type of movement-induced patellar dyskinesia puts disproportionately more strain on the lateral patellar cartilage than the medial and can lead to excessive wear. Furthermore, the guidance of the patella between the two condyles of the femur is also stressed far beyond the norm due to its dorsal fin. These factors naturally also predispose to lateral patellar dislocation. Muscle imbalances between the lateral and medial parts of the quadriceps would further increase the tendency to disorders.

In addition to the overloading of the medial collateral ligament and the patella, insertion tendinopathies and meniscus problems also occur, which are probably due to the fact that the overloaded medial collateral ligament has grown together with the medial meniscus. Bursitis anserina has also been described, which is probably mainly due to the use of the gracilis as an adductor, but the sartorius can also be under increased tension in its insertion on the pes anserinus superfizialis during the shoulder phase of the adducting leg stroke, depending on the degree of stretching.

On swimming, see also the related article in Movement Physiology.

Cause

  • Breaststroke

Predisposing

  • Performance-oriented breaststroke with today’s customary kick straddle
  • Use of fins (e.g. worn when diving) significantly increases the tendency to problems
  • Chest swelling in the event of damage to the knee joint

Diagnosis

Symptoms

  • Pain on exertion during rapid endorotation and wide exorotation rotations of the lower leg
  • Painful pressure in the affected areas
  • Initially only pain during breaststroke, with progression also during other leg-related activities, in severe cases pain at rest

Complications

Therapy

  • Special adaptations of the supplementary training
  • Reduce the amount of training or the intensity of the adduction movement of the thighs, switch to other swimming styles if necessary