Patellofemoral syndrome (PFS) is one of the most common causes of knee pain in active patients and stems from problems with the kneecap (patella) as it moves over the front of the knee. The patella (kneecap) normally tracks up and down when the leg bends and straightens. An imbalance in the quadriceps muscles can affect the tracking causing irritation under the kneecap. Pain is felt in the front of one or both knees or underneath the kneecap. The pain increases gradually over time and is aggravated by prolonged sitting, squats and stair climbing. Some patients will experience minor swelling and the feeling that their knee â€œcatchesâ€ or gives way.
PFS is usually an overuse syndrome caused by doing â€œtoo much, too soon.â€ Other risk factors for PFS include poor biomechanics of the foot (over-pronation), ankle, knee, and hip, decreased strength or flexibility of the upper leg or hip muscles, poor alignment of the leg bones, or a combination of factors. Symptoms tend to come and go depending on the activity level.
â€œShin Splintsâ€ involves a muscular over-use scenario, where very small tears occur in the leg muscles at their point of attachment to the shin bone. They can occur on the outside (called â€œAnterior shin splintsâ€) or inside portion of the shin bone (called â€œPosterior or medial shin splintsâ€). Anterior shin splints involve the Tibialis anterior muscle of the front compartment of the leg while Posterior shin splints involve the Tibialis posterior muscle of the back compartment of the leg. Both of these muscles are involved in slowing down pronation during gait. If the foot over-pronates too rapidly, either or both of these muscles may be called upon to work harder than normal. As a result, fatigue sets in, leading to inefficient force production which leads to micro-tearing of the soft tissue and therefore an inflammatory reaction.
The pain begins as a dull ache during or after running and may become more intense, even during walking, if ignored. The pain in posterior shin splints, also known as Medical tibial stress syndrome (MTSS) is described as being diffuse along the middle and lower portion of the tibia (shin bone). Typically this condition affects runners, although the condition is also seen in ballistic (ie. Jumping) activities such as basketball, dancing or racquet sports. Early in the condition the pain occurs at the beginning of a run, may resolve as the workout continues, and then recurs after the workout. The pain usually resolves with several minutes rest at this stage. In later stages the pain becomes more severe, sharper, and more persistent. In advanced stages of MTSS, the pain can complicate activities of daily living (walking, etc.) and can even occur at rest.
Many of the risk factors are modifiable, thus giving ample opportunity for injury prevention. Extrinsic factors include training methods (too much, too soon, too fast), running surfaces, and improper shoe selection or old shoes. Intrinsic factors are unique to individual athletes and most commonly include over-pronation.
MTSS is not a condition that you want to â€œrun throughâ€ without proper diagnosis and treatment. MTSS occurs along a continuum of stress injuries and can lead to a stress fracture if training continues and the pain is ignored.