The navicular bone is one of 26 bones in the human foot. Located on the top inner side of the middle of the foot. Connects ankle bone to tarsal bones and forms walking arch. Several ligaments and tendons connect to the navicular bone
Rectus femoris is a powerful quadriceps muscle located near hip. Muscle crosses hip and knee joints, helping with knee straightening. Rupture occurs from explosive loads or overuse during activities
ACL is a diagonal ligament between thigh and leg bones in knee joint. Provides knee stability during walking, running and jumping. Contains type 1 and some type 3 collagen
ACL injury is tear or sprain of anterior cruciate ligament connecting femur to tibia. Most common in sports with sudden stops, direction changes and jumping. Symptoms include loud pop, severe pain, rapid swelling and instability
Pronation is natural foot movement during landing, consisting of eversion, dorsiflexion, and abduction. Normal foot is flexible during pronation and rigid during supination. Approximately four degrees of pronation and supination are necessary for forward propulsion
MCL stabilizes knee against valgus and rotational forces. Grade 1-2 injuries typically treated conservatively. Grade 3 injuries may require surgery if severe. Surgery usually needed when combined with ACL tear