Presentation on theme: "Week 8 Muscles and Movements of Lower Extremity – Ch 8 Objectives"— Presentation transcript:
1 Week 8 Muscles and Movements of Lower Extremity – Ch 8 Objectives Explain how anatomical structure affects movement capabilities of lower extremity articulations.Identify factors influencing the relative mobility and stability of lower extremity articulations.Explain the ways in which the lower extremity is adapted to its weightbearing function.Identify muscles that are active during specific lower extremity movements.Describe the biomechanical contributions to common injuries of the lower extremity.
2 Lower Extremity Outline MondayReview epicondylitis and carpal tunnel syndromeHip Joint Structure (Th Fig 7.1)Hip Joint Muscles and Movements (Th Fig 7.23, 7.24)Knee Joint Structure (Th Fig 8.1)Knee Jt Muscles and MovementsCommon knee injuries – patellar chondromalacia (a.k.a. runners knee) and anterior cruciate tearWednesdayAnkle Joint Structure (Th F 9.4)Ankle Jt Muscles and Movements (Th Fig 9.5, Kr Fig 6.16)Common ankle and foot injuries - plantar fascitis, pronated feet
3 Hip Joint Jt Structure - Th Fig 7.1 Uni-articular muscles (Th F 7.24) Flexion - iliopsoasExtension - gluteus maximusAbduction - gluteus medius and minimusAdduction - adductor brevis, longus, & magnusBiarticular musclesHip flexion, knee flexion - sartoriusHip flexion,knee extension - rectus femorisHip extension, knee flexion - hamstringsNote passive and active insufficiency of biarticular muscles
5 Loads on the Hip During swing phase of walking: Compression on hip approx. same as body weight (due to muscle tension)Increases with hard-soled shoesIncreases with gait increases (both support and swing phase)Body weight, impact forces translated upward thru skeleton from feet and muscle tension contribute to compressive load on hip.
6 Compressive forces on hip jt Socket while walking mayexceed 3 to 4 times body wt,5-6 times bw while jogging,and 8-9 times bw whilestumbling
9 Thigh muscles in cross-section – which ones do not cause hip joint movement?
10 Physiological cross-sectional area (PCSA) of hip jt muscles Why are lateral rotators& gluteii muscles so large?
11 Common Injuries of the Hip FracturesUsually of femoral neck, a serious injury usually occurring in elderly with osteoporosisContusionsUsually in anterior aspect of thigh, during contact sportsStrainsUsually to hamstring during sprinting or overstriding
12 Knee Joint Ligaments and cartilage (Th F 8.1) medial and lateral collateral ligamentsanterior and posterior cruciate ligamentsmedial and lateral meniscusMuscles and movements (Kr F 6.4, Adrian F 4.25)Extensorsquadriceps femoris (rectus femoris, vastus lateralis, vastus medialis, vastus intermedius)Flexorshamstrings (semitendinosus, semimembranosus, biceps femoris)
13 Knee Joint Structure: 25% of Alpine skiing injuries are ligament Peripatellar pain (runner’s knee) caused by imbalance of stress on patella
14 Lower Extremity Misalignment: Q angle is larger in females due toWider hip structure, increasingpotential for PFPS (Patellofemoralpain syndrome)
15 Quadriceps Tendon and Patella Force Lines Compressive force at PFJ is ½ bodywt during normal walking, and over3 times bw during stair climbingComp force increases as knee flexionAngle increases
17 Loads on Knee Forces at tibiofemoral Joint Shear stress is greater during open kinetic chain exercises such as knee extensions and knee flexionsCompressive stress is greater during closed kinetic chain exercises such as squats and weight bearing exercises.Forces at Patellofemoral JointWith a squat, reaction force is 7.6 times BW on this joint.Beneficial to rehab of cruciate ligament or patellofemoral surgery
20 Common Injuries of the Knee and Lower Leg ACL injuriesPCL injuriesMCL injuriesProphylactic Knee BracingMeniscus InjuriesIliotibial Band Friction SyndromeBreaststroker’s KneePatellofemoral Pain SyndromeShin Splints
21 Foot and Ankle joint structure Bones and arches of foot (Th F 9.4)Tibia, fibula, calcaneus, talus, other tarsals, metatarsals, phalangesLongitudinal arch, transverse archplantar fasciaMovements of ankle - talocrural joint (Kr Fig 6.14)Movements of foot - subtalar, intertarsal, intermetatarsal, interphalangeal (Cav Fig 3.15, 3.16, 3.17, 4.4, 4.5)
31 Plantar Fascium: Plantar fascitis is 4th most common cause of pain among runners (1st – knee pain, 2nd – shin splints, 3rd- achilles tendonitis)
32 Plantar Fascitis – 4th leading cause of pain in runners What causes plantar fascitis(inflamation of plantar fascium)?anatomic anomaliesmicrotears in fascium and bone spursinadequate flexibility of plantar flexorsinadequate strength of plantar flexorsfunctional pronation (eversion and abduction)overuseoverweightpoorly designed and poorly fitted shoesrunning and jumping on hard surfacessudden increase in stressTreatmentremove the cause(s)Therapeutic treatment to promote body’s natural healingNSAIDSIntermittent ice and heatUltrasound, diathermy, massage
33 Patellar Chrondomalacia (a. k. a Patellar Chrondomalacia (a.k.a. Runner’s Knee) – leading cause of pain in runners)Primary cause is imbalance in forces on patellaIncreased Q anglePronated feetTissues affectedDegrading of articular cartilage of patella & femoral condylesFluid collection, causing joint stiffnessSymptomsPain around patella with no particular injury causing itWorse going upstairs and downstairs, or after sitting awhileFeels like knee needs to be stretchedPrevention/treatmentSurgery is seldom beneficialWet test – walk with wet feet on floor and determine if you have a hypermobile foot. If so, purchase shoes and/or orthotics to decrease degree of foot pronationExercises to increase strength/endurance of vastus medialis
34 Runner’s knee, cont’d Wet test: Safe exercise to develop vasti muscles Do not use knee sleeves!Do not bend knee more than degrees while doing extensions with resistance!
35 Websites for Muscles, Movements, & Problems of Lower Extremity MMG - Patient Education Foot and Ankle TOCMMG - Patient Education Knee TOCProblems on lower extremity:Introductory problems, p 263: 7,8,9,10Additional problems, p : 1,5,6,8,9
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