AI Running Excellence: Achieve Better Health with RunBox [1c66]

Many runners have experienced knee pain to some extent. Many describe this feeling as if an arrow has struck their knee. Indeed, the knee is the most complex joint in the human body, connecting the thigh bone and the shin bone through the knee joint, bearing most of the body's weight.

When lying flat, the knee bears almost no weight; when standing or walking, the knee bears 1-2 times the body weight; when climbing stairs, the knee bears 3-4 times the body weight. As time goes by, the mileage we walk increases, and our knees age and wear out with age.

Pain in the patellofemoral joint at the front of the knee is one of the most common knee injuries among runners. It mainly manifests as pain, instability, and swelling, accounting for 20-40% of all knee problems. Today, I'll explain how to rehabilitate when you experience pain in the patella.

What is patellofemoral pain?

What is the patella? Runners can feel a bone at the front of the knee, which is the patella. The patella slides up and down in the groove formed between the inner and outer condyles at the lower end of the femur, accompanying the flexion and extension of the knee joint. The patella and the groove at the lower end of the femur form the patellofemoral joint surface.

In a normal state, the patella is fixed in position by the quadriceps and patellar tendon, sliding up and down along the groove of the femur, allowing smooth flexion and extension of the knee joint. However, sometimes due to factors like muscle strength imbalance, the patella can rub, collide, or compress against the edge of the femoral groove, causing abnormal stress on the cartilage of the local joint surface, leading to pain.

If the patellofemoral joint is disordered and knee joint activities continue repeatedly, it can worsen patellar pain syndrome. The patellar tendon and the cartilage below it can become inflamed, potentially leading to chronic joint damage. In more severe cases, it can cause damage to the cartilage between the patella and femur, evolving into chondromalacia patellae.

What causes patellofemoral pain?

The most common knee pain among runners is medically diagnosed as 'patellofemoral pain syndrome,' also known as patellar tendinitis, chondromalacia patellae, runner's knee, or jumper's knee. The professional term is 'patellofemoral pain syndrome.' Abnormal patellar movement trajectory is the most direct cause of patellofemoral pain syndrome.

Muscle strength imbalance

The front of the thigh is mainly composed of the quadriceps, which is a powerful muscle for knee extension and is very important for running. If the outer muscle bundle of the quadriceps is significantly stronger than the inner muscle bundle, it will exert an outward pulling force on the patella, causing it to tend to derail.

Tight surrounding soft tissues

The iliotibial band on the outside of the knee joint is connected to the patella. When the iliotibial band is too tight, it pulls the patella outward, which is also an important cause of patellar derailment and cartilage wear, leading to pain.

Insufficient flexibility of the quadriceps can also cause knee pain. The main reason is that the quadriceps are connected to the patella, and tension in the quadriceps causes the patella to be tightly pressed against the surface of the femur, increasing the pressure in the patellofemoral joint.

Previous knee injuries

If there is a history of acute knee injuries, such as collateral ligament injuries, cruciate ligament injuries, or meniscus injuries, even if the injury has healed, there may still be a reduced sense of joint balance or knee instability, making the patella prone to irregular movement.

Insufficient hip strength

In the past decade, numerous studies have found that insufficient hip strength, especially in the abductor muscles, can cause abnormal patellar movement trajectories. This is mainly because insufficient hip abductor strength can cause excessive hip adduction and internal rotation, which is knee valgus, greatly increasing the likelihood of patellar derailment.

What strength training should be done when experiencing knee pain?

Lateral walking with resistance bands

Side plank leg raises

Kneeling leg raises

Supine hip thrusts

Single-leg deadlifts

Squats

Wall sits

Single-leg squats

Lunges

Using knee braces can reduce injuries

Using kinesiology tape and knee braces can reduce abnormal patellar movement trajectories. For most people, the inner muscle bundle of the quadriceps is weaker, and the outer muscle bundle is stronger, creating an imbalance.

This imbalance causes the patella to derail outward due to the stronger pull of the outer muscle bundle. In this case, applying kinesiology tape along the inner muscle bundle of the quadriceps and around the patella can activate the inner muscle bundle of the quadriceps and improve knee proprioception.

Knee braces can also stabilize the patella and distribute patellar pressure. Wearing lightweight knee braces is an effective way to reduce knee pain.