CHAPTER 5

is not technically part of the knee joint, but it can rotate slightly, causing changes in the overall alignment of the knee. There is an interosseous membrane between the tibia and the fibula, which stabilizes their rela- tionship and provides an attachment site for a few muscles, as well as a division between the compartments of muscles on the back and front of the lower leg. Try this now. 1. Find the head of the fibula, just below the outer knee. 2. Flex your foot, touching the floor only your heel, and turn your foot in and out. Feel the muscles on the outer calf contracting and the head of the fibula rotating. Femur

Patella The Support Structures of the Knee and Their Vulnerabilities The menisci The menisci (singular: meniscus, which means “crescent” in Latin) are semicircular cartilage structures that create a cushion, a supportive outer rim on the tibial plateau, and a more secure “seat” for the femoral con- dyles. They are thicker on the outer edge and thinner at the center, creating a deeper in- dented shape to stabilize the rounded shape of the distal femur and distribute its weight onto a larger area. The femur sitting on the tibia with the support of the menisci around the edges is like a cup with a rounded bot- tom sitting in a saucer, rather than on a flat surface (see Figure 5.3). Though the me- nisci can move slightly in response to knee movements, they can also be torn by forceful twisting. Forcing one’s legs into Padmasana without sufficient hip flexibility will cause excessive rotation at the knee, injuring the menisci (see below, Range of Motion). Common alignment variants: Long- Lateral femoral condyle Tibial tuberosity Tibial plateau Tibia Fibula Figure 5.1 Bones of the knee The collateral ligaments The collateral ligaments (medial and later- al) run vertically from the femur to the tibia term wear and tear of the menisci can occur with prolonged medial or lateral rotation of the tibia. This rotation may show on the surface as inwardly or outwardly facing patellae. Medial rotation of the tibia is very common in young people, but if it persists through a career in sports, dance, martial arts or yoga, the dangers to the menisci increase.