Knee & Thigh Chapter 7 Objectives: UNDERSTAND: Anatomy of the knee & thigh Principles of rehabilitation to the knee & knee Preventive/supportive techniques and devices IDENTIFY: Assessment tests for injuries to the knee and thigh RECOGNIZE: Steps in the evaluation format Common injuries to the knee and thigh

Anatomy The Knee Largest joint in the body, but structurally very weak. Unstable bony structure: the femur (longest & strongest bone in the body) sits on top of the smaller tibia (main weight bearing bone of lower leg).

Anatomy Femur -longest and strongest Tibia -main weight bearing bone of lower leg Fibula -non-weight bearing bone of lower leg Patella -(knee cap) encased in powerful patellar tendon

Ligaments Medial Collateral (MCL) -secure femur to tibia - connects to the medial meniscus -Reduce Valgus & varus movement (abduction & adduction of tibia and femur) Lateral Collateral (LCL)-(not as strong) -does not attach to the lateral meniscus Anterior Cruciate (ACL)-form “X” control anterior & posterior movement of femur on the tibia. Posterior Cruciate (PCL)

Other structures Cartilage: (rest on top of tibia, form a cushion for the femur to rest on, and shock-absorption, joint stability, smooth gliding & rotating of the femur and tibia) Medial Meniscus (cartilage) Lateral Meniscus (cartilage) Bursa -closed, fluid-filled sacs, cushion against friction over bone, or where tendon moves over a bone. Synovial membrane -large sac that lines the inside of the knee joint, helps: tendons, ligaments, and bones. Fat pads -soft tissue: weight bearing and absorbing impact

Muscles Quadriceps: Anterior, extend (straighten) lower leg, form patellar tendon (attaches on front of tibia) 1. Rectus femoris 2. vastus medialis-patellar tracking 3. vastus lateralis 4. vastus medialis

Muscles Hamstrings: posterior, flexes the knee, controls the rotary movements of the tibia. 1. Semitendinosus 2. semimembranosus 3. biceps femoris

Muscles & Tendons Vastus Medialis: extension of knee Vastus Lateralis: extension of knee Vastus Intermedius: extension of knee Rectus Femoris: extension of knee, flexion of hip Gracilis: adduction of hip and flexion of knee Sartorius: flexion & rotation of hip & knee Semitendinosus: knee flexion & medial rotation Semimebranosus: Knee flexion & medial rotation

Muscles & Tendons Popliteus: flexion of knee & medial rotation Biceps Femoris: flexion of knee & lateral rotation Gastrocnemius: knee flexion Plantaris: knee flexion

Assessment Tests Test for knee ligament stability: - abduction or valgus stress: medial joint stability -adduction or varus stress: lateral joint stability -anterior drawer: acl -posterior drawer: pcl -Lachman’s: acl

Common Injuries Ligament sprains: 1st, 2nd, 3rd degrees. -Contusion: direct blow to knee joint -Torsion: feet are fixed and body/injured joint is twisted (most often menisci) -Shearing: force delivered to opposite side of joint Patellar Tendinitis: Inflammation above/below patella. (pain after exercise, swelling) Ice & rest

Common Injuries Chondromalacis Patellae: irritation and softening of the cartilage on the posterior aspect of the patella, causing unusual tracking of the patella as it moves. (causes: muscle weakness, imbalance, females: wider pelvic) Osgood-Schlatter: Adolescents due to rapid growth during growth spurts, swelling below one/both knees. (causes: inflammation of the tibial tubercle, where the patellar tendon attaches) Rest & maybe cast Muscular strains: PRICES