Nerves transmit electrical signals throughout the body, enabling movement and sensation. For complex joints like the knee, nerves coordinate motion and provide feedback about position and stimuli.
Major Nerves Around the Knee
Several major nerves pass through or supply the knee region. The femoral nerve originates in the lower back, travels down the front of the thigh, and branches to the knee. It supports muscles that straighten the knee, providing sensation to the thigh and inner lower leg.
The sciatic nerve descends from the pelvis into the thigh, dividing into two main branches just above the knee: the common peroneal nerve and the tibial nerve. The common peroneal nerve winds around the outer side of the knee, near the fibula head. It branches to muscles that lift the foot and provides sensation to the outer lower leg and top of the foot. The tibial nerve continues down the back of the leg, controlling muscles that bend the knee and point the foot downward, providing sensation to the back of the lower leg and sole of the foot.
The saphenous nerve, a femoral nerve branch, is primarily sensory. It travels along the inner thigh and knee, extending to the inner lower leg and foot. This nerve relays sensations from the skin in these areas.
Nerves and Knee Function
Nerves enable the knee’s function through sensory and motor roles. Sensory nerves provide information about the knee’s state, allowing perception of touch, pressure, temperature, and pain. This feedback helps avoid injury and react to external forces.
Proprioception, the body’s ability to sense its position and movement without sight, is a key sensory function. Nerves around the knee contribute to this sense, informing the brain about knee angle and muscle tension. This feedback helps maintain balance, coordinate movements, and ensure stability during activities like walking or running.
Motor nerves facilitate movement by transmitting signals from the brain and spinal cord to the muscles surrounding the knee. These signals instruct muscles to contract, allowing actions like bending (flexion) and straightening (extension) the leg. Coordinated muscle action, guided by nerve impulses, provides power and stability for daily activities and physical exertion.
Common Nerve Issues Affecting the Knee
Nerves around the knee can experience problems, leading to discomfort or impaired function. Nerve compression, or entrapment, occurs when surrounding tissues, bones, or pressure pinch a nerve. The common peroneal nerve is vulnerable to compression as it wraps around the fibular head on the outside of the knee. This can result from prolonged leg crossing, tight casts, braces, or extended squatting.
Nerve compression symptoms include numbness, tingling, weakness, or a burning sensation in the affected area. The saphenous nerve can also experience entrapment, causing pain, numbness, or tingling along the inner thigh, knee, or lower leg. Direct trauma, such as fractures, dislocations, or severe ligament injuries near the knee, can damage nerves by stretching, compressing, or severing them.
Nerve damage can also result from surgical procedures around the knee due to nerve proximity to the surgical site. Neuropathy, a type of nerve damage, can affect the knee. While it can stem from localized trauma, it may also be a symptom of systemic conditions like diabetes, which can impair nerve function throughout the body, including the lower extremities.
Maintaining Nerve Health in Your Knees
Protecting knee nerves involves preventive measures and self-care. Safe exercise practices, including proper warm-up routines and correct form, avoid undue stress on the knee joint. Wearing appropriate footwear that provides adequate support and avoiding repetitive motions that strain the knees also prevents nerve irritation.
Managing underlying health conditions, such as diabetes, is important for overall nerve health. Effective management helps prevent widespread nerve damage, including that affecting the knee. Maintaining a healthy body weight reduces the load on knee joints, minimizing stress on surrounding nerves and tissues.
Regular physical activity supports circulation and muscle strength, contributing to healthier nerves. If persistent pain, numbness, or tingling occurs in the knee or lower leg, seek medical advice. Addressing issues early can help preserve nerve function and overall knee health.