CHAPTER 8: THE LOWER EXTREMITY: KNEE, ANKLE, AND FOOT KINESIOLOGY Scientific Basis of Human Motion, 12 th edition Hamilton, Weimar & Luttgens Presentation Created by TK Koesterer, Ph.D., ATC Humboldt State University Revised by Hamilton & Weimar McGraw-Hill/Irwin Copyright 2012 by The McGraw-Hill Companies, Inc. All rights reserved.
THE KNEE JOINT: STRUCTURE Hinge joint. Two condyles of femur articulate with tibial plateaus. Patella articulates with patellar surface of femur. Fig 8.2 Menisci Circular rims of fibrocartilage. Lateral an incomplete circle. Medial C shaped. Thick peripheral borders, tapering to a thin inner edge. Fig 8.4 8-2
MOVEMENTS Fig 8.6 8-3
MUSCLES OF THE KNEE JOINT Anterior Quadriceps Group Rectus femoris Vastus intermedius Vastus lateralis Vastus medialis Posterior Hamstring Group Biceps femoris Semimembranosus Semitendinosus Gastrocnemius 8-4
MUSCLES OF THE KNEE JOINT Rectus Femoris Function: Powerful knee extensor. Fig 8.7 8-5
MUSCLES OF THE KNEE JOINT Vastus intermedius Vastus lateralis Vastus medialis Function: Powerful knee extensors. Fig 8.8 8-6
MUSCLES OF THE KNEE JOINT Biceps femoris Function: Flexes knee & external rotation of tibia in nonweight bearing. Semimembranosus Semitendinosus Function: Flexion and internal rotation in non-weight bearing. Fig 8.10 8-7
MUSCLES OF THE KNEE JOINT Gastrocnemius a.k.a. Calf muscle Function: Helps flex knee. In weight bearing can help maintain knee extension. Fig 8.23 8-8
MUSCULAR ANALYSIS OF FUNDAMENTAL MOVEMENTS OF THE LEG AT THE KNEE JOINT Flexion: Hamstrings Extension: Quadriceps External Rotation: Biceps femoris Can only occur when knee is flexed & nonweight bearing. Internal Rotation: Semimembranosus, semitendinosus Can only occur when knee is flexed & nonweight bearing. 8-9
COMMON INJURIES OF THE LEG, KNEE AND ANKLE The Leg: Tibial Stress Injuries Often called shin splints. An overuse injury. Repeated microtears where tibialis posterior or anterior attaches to tibia, inflammation. Sprains in interosseous membrane. Tenderness & pain on medial surface of tibia. Rest, softer surface and supporting the arch are best treatment. 8-10
COMMON INJURIES OF THE LEG, KNEE AND ANKLE The Leg: Fracture Most common among the young. Most common to lower 2/3 of fibula. May result in instability of ankle joint. Severity based on bone displacement: More displaced - more severe. The Leg: Shin Contusions Common based on exposed nature of tibia. Usually from a direct blow. May damage periosteum. Shin guards are recommended in activities in which leg impacts are common. 8-11
COMMON INJURIES OF THE LEG, KNEE AND ANKLE The Knee: Collateral Ligament Sprain Direct blow to either side of knee. Majority are blows from lateral side causing medial collateral ligament damage. Depending on amount of force the following structures could be injured: Medial collateral ligament Medial meniscus Anterior cruciate ligament The Knee: Chondromalacia Degeneration of cartilage on articulating surface of patella. Pain, on movement, swelling, grating sensation. Treatment through evaluation of lower body biomechanics, rehabilitative exercises, limiting activities. 8-12
COMMON INJURIES OF THE LEG, KNEE AND ANKLE The Knee: Osgood Schlatter Disease Due to repeated overuse of knee extensors. Tearing or avulsion of epiphysis of tibial tuberosity. Swelling, pain on activity & kneeling. Treat with rest, ice, rehabilitative exercises. 8-13
THE ANKLE AND FOOT: The foot provides for support and propulsion. Movements within the foot occur primarily at the subtalar and midtarsal joints. The ankle serves to unite the foot and the leg. 8-14
STRUCTURE OF THE ANKLE Hinge joint Articulation of talus with malleoli of tibia & fibula. Bound together by ligaments. Sustentaculum tali Tibia Talus Calcaneous Fibula Fig 8.12 8-15
STRUCTURE OF THE FOOT An elastic arched structure. Talus is the keystone. Comprised of two arches: Longitudinal Transverse Fig 8.15 8-16
STRUCTURE OF THE FOOT Longitudinal arch: Heel to heads of five metatarsals. Supported by the plantar fascia. Transverse arch: Side-to-side concavity. Anterior tarsal bones & metatarsals. Fig 8.16 8-17
SUBTALAR JOINT Joint between underside of talus and upper & anterior aspects of calcaneus. Plantar calcaneonavicular spring ligament helps support talus. Fig 8.17b 8-18
FOOT JOINTS Midtarsal Joint (Chopart s Joint): Consists of two articulations: Calcaneocuboid: Nonaxial permits only gliding. Talonavicular: Modified ball-and-socket permits restricted motion. Tarsometatarsal Joints: Movements are gliding. Intermetatarsal Joints: spreading or flattening. Metatarsophalangeal Joints: Modified condyloid joints. Interphalangeal Joints: Hinge joints. 8-19
MOVEMENTS OF FOOT AT THE ANKLE, TARSAL, & TOE JOINTS Fig 8.20 8-20
MUSCLES OF THE ANKLE & FOOT Location: 22 muscle of the ankle & foot. 11 muscles are extrinsic. 11 muscles are intrinsic Intrinsic: located entirely within the foot Extrinsic: distal tendon attachments 8-21
MUSCLES OF THE ANKLE & FOOT Gastrocnemius Function: powerful plantar flexor. Fast twitch. Allows one to rise on toes, lift body weight. Advantageous leverage. Fig 8.23 8-22
COMMON INJURIES OF THE LEG, KNEE AND ANKLE The Ankle: Strain (tendons) Due to impact that forces ankle beyond normal range. Results in tearing at myotendinous junction. May cause pain, weakness, possible deformity. Potentially very debilitating. 8-23
COMMON INJURIES OF THE LEG, KNEE AND ANKLE The Ankle: Sprains (ligaments) Usually associated with forceful inversion of the foot. In this case the lateral ligaments stretched or torn, or may rupture. Results in pain, swelling, disability. 8-24
COMMON INJURIES OF THE LEG, KNEE AND ANKLE The Ankle: Fracture Same causes as ankle sprains. The majority occur to malleoli. More serious fractures sometimes dislocate. 8-25
COMMON INJURIES OF THE LEG, KNEE AND ANKLE The Foot: Plantar Fasciitis Pain and tenderness along the sole of the foot. May be due to inflammation, micro tears, or rupture of the plantar fascia. Is generally an overuse injury; lack of flexibility may be contributory. Stretching has been shown to be helpful. 8-26