Cherish your knees and keep running

Under the correct leadership of the Party and the State and the concerted efforts of the whole nation, the COVID-19 epidemic has been effectively controlled, and people have stepped out of their homes to keep fit. Running has become one of the most popular sports because it is not restricted by time, space, number of people, and equipment. However, due to people's weak awareness of sports injury prevention and differences in individual exercise habits, the "runner's knee" injury caused by running remains high.

Among the "runner's knee" injuries caused by running, 25% to 40% of people suffer from patellofemoral pain syndrome, which is the main cause of "runner's knee". This will not only consume people's enthusiasm for running, but also cause more serious injuries due to momentary negligence and progress to knee osteoarthritis. Therefore, actively preventing injuries, correctly understanding and choosing a suitable rehabilitation method to prevent and treat injuries can effectively reduce the occurrence or recurrence of sports injuries.

Today, let’s learn about patellofemoral pain syndrome and rehabilitation!

Patellofemoral pain syndrome

Patellofemoral pain syndrome refers to diffuse peripatellar or retropatellar and popliteal pain when squatting, running, going up and down stairs, and standing up from a sitting position. It is the result of the combined effects of multiple complex factors such as anatomy, biomechanics, psychology, society, and behavior.

1. Causes

The causes can be divided into two categories: functional disorders and structural abnormalities.

Functional disorders include: mechanical imbalance of the vastus medialis and vastus lateralis, mechanical imbalance of the quadriceps and hamstrings, weakness of the lateral gluteal muscles, and tightness of the tensor fasciae latae, gastrocnemius, and soleus.

Structural abnormalities include: abnormal morphology of the patella and trochlea, abnormal Q angle, excessive pronation of the foot, etc.

2. Physical Examination

1. Patella grinding experiment

The subject straightens his lower limbs, and the examiner pushes the patella distally along the trochlear groove. The subject actively contracts the quadriceps femoris to resist the downward movement of the patella. If pain occurs during the examination and he stops moving or crepitus occurs, it is a positive test.

2. Knee extension resistance test

The examiner holds the subject's thigh with one hand and applies resistance to the calf with the other hand, allowing the subject's knee joint to be gradually straightened from a flexed position. A positive result is considered if pain occurs. Most patients experience pain at 30° to 50°.

3. Single-leg half squat test

The subject stood on one leg and gradually squatted down, and if the knee felt weak or painful it was considered positive.

3. Diagnosis

Currently, there is no specific imaging diagnostic method for patellar pain syndrome. A meta-analysis of diagnostic tests for patellar pain syndrome showed that the diagnosis can be made if two of the following three conditions are met: ① pain when the quadriceps contract; ② pain when squatting; ③ pain around the patella when palpated.

IV. Rehabilitation Treatment

Under normal circumstances, the patella slides in the intercondylar fossa of the distal femur. When the sliding track of the patella deviates due to various reasons, the pressure and friction between the patella and femur increase, and the cartilage wear increases, causing the joint structure to be destroyed and aseptic inflammation to exude edema, causing joint pain. The main function of rehabilitation treatment is to reduce inflammation, swelling and pain, and correct functional disorders and structural abnormalities.

1. Acute phase

We should follow the POLICE principle, including protection, optimal loading, ice, compression, and elevation of the affected limb. We should protect the joints, reduce the amount of exercise, reduce the local load on the joints, and promote the disappearance of inflammation.

2. Recovery period

(1) Relax tense muscles

(2) Muscle strength training

(3) Other physical therapy

Patellar muscle tape, patellar orthosis, traditional rehabilitation therapy and other physical therapy methods, etc.