Patellofemoral pain syndrome (PFPS) often termed as “runner’s knee”, is commonly characterized by pain at the front of the knee, around or behind the kneecap (patella). The pain often stems from irritation or inflammation in the patellofemoral joint (PFJ) or adjacent tissues, triggered by malalignment, overuse or biomechanical issues.
Anatomy
A patellofemoral joint consists of the patella sitting within the femur bone acting as a pulley to when the knee bends and straightens. Excessive stress on the PFJ can increase the activity within the patella and/or raise the amount of water in the patella. This increased water content can lead to higher pressure inside the joint, which may trigger pain.
Causes
Several factors contribute to the development of PFPS, including:
- Overuse and Repetitive Motion: Activities that involve repetitive bending and straightening of the knee, such as running, cycling, or jumping, can place excessive stress on the patellofemoral joint.
- Poor Biomechanics: Issues such as flat feet, improper running form, muscle imbalances, patellar malalignment and or maltracking.
- Weak or Tight Muscles: Weakness in the quadriceps, hip abductors, or core muscles, as well as tightness in the hamstrings, calves or iliotibial (IT) band, can alter the alignment of the patella.
- Previous Injuries: A history of knee injuries, such as ligament tears or fractures, can increase the risk of PFPS.
- Improper Footwear: Worn-out or unsupportive shoes or high heels can lead to poor knee alignment and exacerbate symptoms.
Symptoms of PFPS
The hallmark symptom of PFPS is a dull, aching pain around or behind the kneecap. This pain often worsens with activities such as:
- Climbing or descending stairs
- Squatting or kneeling
- Sitting for prolonged periods with the knees bent (sometimes called “cinema sign”)
- Running, particularly downhill
Some individuals may also experience a grinding or clicking sensation in the knee during movement.
Who Does PFPS Affect?
PFPS can affect people of all ages but is most common in:
- Athletes: Runners, cyclists, and individuals involved in sports with repetitive knee movements are particularly susceptible.
- Adolescents: Growing teenagers, especially females, may develop PFPS due to rapid growth spurts that alter the alignment of the knee joint.
- Individuals with Sedentary Lifestyles: Weak muscles resulting from inactivity can lead to improper kneecap tracking and increase the risk of PFPS.
- Women: Women are more likely to develop PFPS due to anatomical differences, such as a wider pelvis, which can affect knee alignment.
How Is PFPS Managed?
Recent guidelines have encouraged incorporation of exercise therapy focussing on the hip and knee to decrease pain and improve function. Exercise therapy combined with interventions such as taping, and foot orthoses has been deemed effective in short-term management.
A structured exercise program designed specifically for the individual, their symptoms and goals, can have significant functional improvements, aid return to sport and daily activities and help prevent recurrence.
Some examples of exercises to manage PFPS are:
- Sit to stands or squats
- Bridge
- Crab walks
- Quads isometric extensions
It should be noted that some exercises may not be appropriate depending on symptoms and ability and an assessment should be completed with a physiotherapist prior to commencing an exercise program. For long-term management and return to sport, an exercise program for PFPS may also include a gait assessment and running drills. If you think you might have PFPS, schedule an appointment with one of our Physiotherapists.
Resources:
PhysioNetwork
Evidence-based framework for a pathomechanical model of patellofemoral pain: 2017 patellofemoral pain consensus statement from the 4th International Patellofemoral Pain Research Retreat, Manchester, UK: part 3
