- January 15, 2019
- Posted by: Daniel Ryan
- Category: Knee Injuries
Runner’s Knee, or more scientifically termed ‘Patellofemoral Pain Syndrome’ is one of the most common causes of pain at the front of the knee in runners and sports people of all ages. The pain and stiffness results from mal-tracking of the kneecap on its underlying joint surfaces, which can make it difficult to climb stairs, kneel, participate in sport and perform everyday activities. Many factors can contribute to the development of this condition, but it is easily resolved with appropriate physiotherapy, and typically resolves within 6-8 weeks with appropriate management.
Signs and Symptoms
The most common symptom of Runner’s Knee is a dull, aching pain at the front of the knee. This pain generally has a gradual onset that worsens with activity and often occurs in both knees simultaneously.
Other symptoms can include:
- Pain with repetitive bending and straightening of the knee, as occurs in climbing stairs, jumping and squatting.
- Popping, cracking and grinding sounds in your knee when squatting or jumping, especially after periods of prolonged standing and sitting.
- Pain with prolonged periods of sitting with your knees bent.
Incidence and Prevalence
Patellofemoral knee pain is estimated to effect up to 22% of the general population, and 29% of adolescent populations. It is suggested that this condition is more prevalent in female populations, with one study suggesting that prevalence is 1.5 times greater in females compared to males (Taunton et al 2002). However, this condition can occur in athletes and non-athletes of all genders and ages.
The sports where patellofemoral pain is most common include running, jumping, landing and squatting, and include running, tennis, netball, volleyball and basketball.
During normal motion, your kneecap glides within a grove in your femur. As your knee bends, pressure is naturally applied to this groove from the backside of the kneecap.
In Runner’s Knee, a number of contributing factors cause the kneecap to be pulled slightly to the side of this ‘optimal groove’, making it rub against the femur. Then, during repetitive motions such as walking, running and climbing stairs this causes irritation on the surfaces at the back of the kneecap.
In some cases, a condition called chondromalacia patellae may also be present. This refers to a softening and breaking down of the cartilage on the underside of the kneecap if this condition continues for a long time. This can lead to inflammation of the synovium and pain in the underlying bone.