Pain in the patellofemoral joint

Patellofemoral Pain (PFP) is a word that refers to “non-specific” pain or soreness under and/or around the kneecap. It is one of the most prevalent causes of knee pain in active and non-active people of all ages; girls experience patellofemoral pain twice as often as males. Because of its frequency among runners, PFP is commonly referred to as “Runner’s Knee.”

 

Function and Anatomy

The thigh bone (femur), shin bone (tibia), and knee cap make up the knee joint, which is vast and complex (patella). The patella is a big sesamoid bone that attaches to the upper front portion of the tibia as the tendon of the thigh muscle (quadriceps femoris muscle group) crosses over and in front of the knee joint. The patellofemoral joint is formed when the knee cap rests within a “groove” (the trochlea) at the lower end of the femur and forms its own joint. The kneecap travels up and down this groove as the knee bends (flexes) and straightens (extends). The patella’s job is to generate leverage and boost the mechanical advantage of the quadriceps muscle; without it, we’d lose half our knee extension strength. The patella also acts as a shock absorber for the front of the knee.

 

 

Symptoms

A ‘dull’ or ‘sharp’ discomfort or pain ‘under’ or ‘around’ the kneecap are common symptoms of patellofemoral pain. Squatting, walking up and down stairs, running, and sitting for long periods of time are all common activities related with PFP. Tendonitis or tendonosis can cause localized pain above or below the kneecap, and instability of the knee can indicate a cartilage or ligament damage. Other diagnoses that must be explored and ruled out include chondromalacia patellae (a “softening” or degeneration of the cartilage under the knee cap), arthritis, and plica, to name a few.

 

 

Causes

Patellofemoral pain is thought to be produced by incorrect kneecap tracking and can be caused by a variety of reasons such as muscular tension, weakness, and “overuse.” PFP is also caused by individual anatomical variables and incorrect equipment fit.

 

Muscle tightness and/or weakness can change the line of pull either directly or indirectly by causing excessive femur adduction and internal rotation. The quadriceps (femoris) are the muscle group that has the most direct impact on patellar tracking, but the iIiotibial band, hip extensors, abductors, adductors, hamstrings, and calf muscles also have an impact. Excessive internal rotation of the tibia can also stress the patella due to tight and weak lower leg muscles and/or excessive foot pronation.

 

Overuse simply means “doing too much too soon” or doing an action or activity that the body or a bodily part isn’t ready for on a regular basis. Inflammation, discomfort, and damage are common outcomes when physical demands exceed tissue tolerance without proper recovery. This holds true for any type of repetitive activity, including sports and training.

 

Overuse injuries are most likely caused by “training blunders” in athletes or anyone who participates in a regular training program. Mismanagement of the frequency, volume, intensity, and recuperation within a training program are the most typical “errors” that contribute to injury. These factors are a part of any training program and must be managed individually and as a group in such a way that the body develops a “tolerance” to the activity and can proceed without damage.

 

Lower extremity workouts that lack correct warm-up, flexibility, strength, and technique are also common in those with patellofemoral pain. If you’re new to strength training, start light and work your way up; if you’re doing squats, start with partial squats rather than complete squats. If you’re new to running, start with a walk/jog program and gradually increase your mileage. Start with sprints and hill repeats when you’ve established a strong foundation of strength and endurance. If you miss a few exercises, don’t resume where you left off; instead, adjust the volume and intensity as needed and gradually get back into shape. Be consistent with your training regimen and learn good technique for all workouts.

 

Leg length inequalities, flat feet (pes planus), high arches (pes cavus), and a knee cap that sits either too high or too low in respect to its ideal position in the femoral groove are all anatomical risk factors for PFP. By dragging the kneecap too far to the outside and “off track,” a broad pelvic girdle can cause a patellar alignment problem. The Q-angle effect occurs more frequently in females than in males. Excessive stress on the patellofemoral joint is also caused by improper equipment fit, such as footwear and bike fit.

 

 

Treatment

Effective therapy for any injury begins with a correct diagnosis. Depending on the severity of the injury, activity modification or total rest and ice are used to treat patellofemoral pain. Ice is a natural anti-inflammatory and analgesic that can be used whenever there is pain, whether it is a day or several months after the accident.

 

If you spend the majority of your day sitting, attempt to alter the posture of your knees from straight to no more than a 90-degree bend on a regular basis. PFP might be worse by staying in one posture for an extended period of time. When you’re in a lot of discomfort, try to stay away from stairs and unnecessary squatting. Replace worn shoes whether you’re a runner or not. In all shoes, consider replacing the insole because increased shock absorption and support has been demonstrated to lessen PFP. A bike fit will help you eliminate unnecessary patellofemoral stress while maximizing efficiency and power if you’re a rider.

 

Gentle stretching and mobility exercises for the hip, thigh, and calf muscles should be started as soon as tolerated. Stretching improves patellar alignment and lowers kneecap compression forces. Then, with adequate strengthening of the same muscle areas and a gradual reintroduction to training, you can get back into shape. Strength supports appropriate alignment and increases the muscles’ and joints’ ability to absorb and distribute stresses.

 

Before you resume training, review your program and identify and correct any mobility and strength imbalances that may be contributing to dysfunctional movement patterns and poor mechanics, being sure to incorporate core, hip, and lower leg muscles, as well as the thigh. To avoid any training errors that may have led to the injury, evaluate and address the factors of frequency, volume, intensity, and recovery within your program.

 

When you return to training, be careful not to pick up where you left off. Depending on how much time you missed, you may need to start at 25% – 50% of your normal program and gradually increase by 10% or so each week, or as directed by your physical therapist, doctor, or coach. Within and between workouts, make sure to incorporate enough warm-up and recuperation time.

 

Prevention
The best preventive advice, as with most injuries, may be summed up in what I call the PETR Principles, which comprise adequate Preparation, Equipment, Technique, and Recovery.

Preparation: The purpose of preparation is to raise the physiological tolerance of the body so that the demands of any given sport or activity do not break it down to the point of harm. The more prepared the body is, the more stress and damage resistant it is. Warming up, flexibility, strength, endurance, and balance training are all essential components of preparation for people who participate in any sport. The hip, thigh, and calf muscles must have adequate flexibility and strength to control patellar alignment and reduce excessive adduction and internal rotation of the thigh (femur) and internal rotation of the shin (tibia). The hip adductors, abductors, and external rotators are significant because they control thigh and lower leg adduction and internal rotation, which can affect foot pronation.

 

Footwear and bike fit are two items that are specific to patellofemoral discomfort. For proper support, shock absorption, and fit, activity-specific footwear is essential. For example, jogging with a tennis or basketball shoe is not recommended because ‘court’ shoes are not made for the distance and steady state impact of jogging. Wear a shoe that provides decent support, shock absorption, and fits well if you’ll be on your feet all day.

 

Cycling is a type of exercise that involves repeatedly moving the legs over a wide range of motion against resistance while sitting in a fixed seat leaning forward. If not properly fitted, this posture provides a certain geometry between the body and the bike, which can inflict undue stress on the knees, hips, and back. This geometry, on the other hand, can be tuned to produce the least amount of stress while optimizing force production when properly fitted.

 

Technique refers to the movement patterns required to efficiently and successfully conduct an activity or sport. In general, the better the technique, the lower the danger of damage and the higher the likelihood of a successful outcome.

 

Cadence is a wonderful illustration of technique for runners. Simply put, cadence refers to the number of steps made in a given amount of time, usually one minute. Runners with a greater cadence (at least 180 steps per minute) have a shorter stride and a foot-strike that is lower to the ground. When compared to people who walk at a lower cadence (160 to 170 steps per minute), this reduces impact forces and improves efficiency. Beginner and inexperienced runners have a tendency to over-stride, putting extra stress on the knees, as well as the feet, hips, and back. Technique is important in any action or sport, and it can be learned.

 

Physiologic adaptation cannot take place without recovery. The body increases strength and endurance through adaptation, and it repairs and regenerates during rest and recovery. Easy training days, entire days off, and sleep can all help with recovery. Our sleep and recovery requirements grow in tandem with the volume and intensity of our workouts. We lose fitness if we don’t get enough rest and sleep. The key to being stronger and quicker is recovery. Strength is gained during rest intervals rather than during workouts.

 

Bottom line: adhering to the concepts of adequate preparation, equipment, technique, and rehabilitation will help prevent patellofemoral joint overuse and injury.