Knee Movement and Exercise Guidelines

Anterior knee pain has been referred to as the “miserable alignment syndrome,” and the cause has been described as a combination of factors including femoral anteversion, patellar malalignment, increased quadriceps angle (Q-angle), and tibial external rotation (17). Overuse and training on unsuitable surfaces are common contributors to anterior knee pain and often occur with running, jumping, and bicycling activities. Collectively, these factors alter the tracking of the patella in the trochlear groove, resulting from tightness of surrounding tissues (e.g., lateral retinaculum, iliotibial band), imbalance in the forces acting on the patella, and possibly a change in foot biomechanics (e.g., excessive or improper pronation or supination) (17, 51). Thus education on proper running surfaces (concrete vs. asphalt vs. treadmill), appropriate footwear, and the benefits of cross-training is quite important in addressing overuse.

Muscular imbalances surrounding anterior knee pain commonly have to do with the relationship between the vastus lateralis and a portion of the vastus medialis, the vastus medialis obliquus (VMO). The common belief is that the vastus lateralis overpowers the VMO and pulls excessively on the patella, causing the patella to move laterally when the quadriceps muscles are active. Although it is possible that such an imbalance exists, its treatment is rather controversial. It would seem logical to strengthen the VMO to improve this balance, but research has yet to demonstrate that preferential VMO recruitment is possible. More recent research has suggested that in addition to the strength and function of the quadriceps, proximal muscle weakness (e.g., gluteus medius) may be a contributing factor to anterior knee pain. Specifically, weakness in the gluteus medius will allow the contralateral pelvis to drop, thereby forcing the stance limb into a position of internal femoral and tibial rotation (17, 42). This change in the alignment of the pelvis, femur, and tibia may also facilitate hyperpronation of the foot and exacerbate the already poor alignment pattern (17).

Because the quadriceps muscles help clients walk up stairs and assist deceleration of the body during walking on level surfaces and down steps, general quadriceps strengthening does improve patellofemoral function and reduces anterior knee pain. However, weakness in the proximal muscles will decrease an individual’s general ability to stabilize the lower extremity, particular during dynamic movements. Thus, specific exercises emphasizing unilateral balance tasks and targeting hip strength are recognized as an essential component of treatment and prevention of anterior knee pain. Care must be taken, however, to use exercises that do not adversely stress the patellofemoral joint. No exercises are explicitly contraindicated for clients experiencing anterior knee pain, but some exercises require caution. Deep squats and other closed kinetic chain exercises requiring knee flexion of more than 90° must be prescribed with caution, as these increase compression between the patella and femur. Additionally, most open kinetic chain exercises, such as knee extension, in the last 30° increase patellofemoral joint load and should be avoided. Aerobic endurance activities such as high-impact aerobic dance or step aerobics, as well as aerobic endurance training that places the knee in positions such as a deep lunging or squatting position, would be contraindicated. Typically, cycling (provided seat height is appropriate) and water-based aerobic training activities are recommended to minimize impact and trauma to the knee joint and maintain an individual’s aerobic condition during training. It is also common for clients with anterior knee pain to use a form of taping (e.g., McConnell), bracing, or orthotics to assist with stabilization of the patella and support proper mechanical alignment. Table 21.7 provides movement guidelines for anterior knee pain and other knee problems.

Table 21.7 Knee Movement and Exercise Guidelines

*Although these movement and exercise contraindications are commonly used, it should be remembered that individual clients react to anterior knee pain differently; therefore, for clients with this general diagnosis, the ranges of motion and exercises provided should be considered relative. Exercises and movements that cause anterior knee pain become absolute contraindications and should be eliminated from the client’s exercise program.