膝关节康复课件

1、The Knee ComplexThe Knee ComplexObjectives1、to identify the structures of the knee complex, including joint type, articular shape, and the surrounding tissues 2、to describe joint motions occurring at the knee complex, including physiological and accessory movements, muscle actions, and factors check

2、ing knee motions Objectives1、to identify the st3、to understand the stability mechanism of the knee complex and the possible mechanisms of injury 4、to understand functions of the meniscus and the ligaments surrounding the knee complex 5、to explicate functions of the sesamoid bone such as the patella

3、as well as its significance in biomechanics3、to understand the stability 第一节、Functions of the Knee1、To provide stability for weight bearing 2、To allow mobility of the leg in space 3、To transmit the loads from the upper body and thigh to the lower leg 第一节、Functions of the Knee第二节、Joint Structure of t

4、he Knee ComplexJoints at the knee complex Patella meniscus Q-angle 第二节、Joint Structure of the KneJoints at the knee complextibiofemoral joint (knee joint)： principal joint at the knee complex patellofemoral joint NOTE： In Neumanns book, the tibiofemoral joint was divided into medial and lateral tibi

5、ofemoral joints Joints at the knee complextibi膝关节康复课件Tibiofemoral joint (TF joint) proximal components： femur convex femoral condyles distal components： tibia concave superior surface of the tibial plateau C-shaped medial meniscus and O-shaped lateral meniscusjoint type： hinged jointDOF = 2 because

6、of the menisci between the articular surfaces Tibiofemoral joint (TF joint)motions： concave on convex knee flexion/ extension with posterior/ anterior glide of the tibial plateau on the femoral condyles tibia inward/ outward rotation： only occurs at the knee flexed position resting position： slight

7、knee flexion (10) closed-packed position： full knee extension motions： concave on convex 膝关节康复课件Patellofemoral joint (PF joint) proximal components： femur convex femoral condyles distal components： patella 3 concave facets of the patella joint type： saddle joint DOF = 2 motions superior/ inferior gl

8、ide associated with knee extension/ flexion medial-lateral shift： c-curve movement Patellofemoral joint (PF jointPatellalargest sesamoid bone in the body location： embedded in quadriceps tendon function： to increase mechanical leverage of the quadriceps Patellalargest sesamoid bone ipatellar compres

9、sion force：to pull the patella against the anterior surface of the femur increased with knee flexion patellar compression force：to patella contact areaAt full extension, the distal portion of the patella is in contact with the superior portion of the trochlea As knee flexion, the contact area moves

10、proximately Contact area increases from 0.8 cm2 at knee full extension to 4 cm2 at 90 of flexion (Hehne, 1990) patella contact areaAt full exMeniscus medial meniscus： C-shaped lateral meniscus： O-shaped functions to deepen the tibial plateau for knee stability to absorb the ground reaction forces： c

11、arrying 40-70% of loads across the knee joint Meniscus medial meniscus： C-shMeniscus4. removal of menisci increases the magnitude of stresses on the cartilage of the tibia plateau changes the size and location of tibiofemoral contact area Meniscus4. removal of menisciMeniscus 5. movements of meniscu

12、s Both menisci distorted and moved posteriorly during knee flexion and anteriorly during knee extension In rotation, both menisci follow the motions of the femoral condyles Movements significantly greater in weight-bearing conditions Meniscus 5. movements of menQ anglefull name： quadriceps angle the

13、 angle formed by the line of pull of the quadriceps and the line representing patellar tendonmale： 12 female： 15 Q anglefull name： quadriceps aThe Q angle is an estimate of the effective angle at which the quadriceps averages its pull. defined as the angle formed by the line of pull of the quadricep

14、s and the line representing the patellar tendon. It is determined by drawing a line from the Anterior Superior Iliac Spine to the center of your knee cap and a second line from the center of your knee cap to the insertion of the patellar tendon . Normal is below 12 degrees, abnormal is usually consi

15、dered to be above 15 degrees. The Q angle is an estimate of 第三节 Kinematics of the Kneeknee flexion/ extension tibia inward and outward rotation 第三节 Kinematics of the KneekneKnee flexion and extension1. joint involved tibiofemoral joint patellofemoral joint 2. plane of motion： sagittal plane (not rea

16、lly) Knee flexion and extension1. 3. axis of rotation a frontal axis passing through the center of the medial and lateral epicondyles of the femur instant center of rotation (IAR)： axis of rotation changes through the range of motion (not a fixed point) path of IAR forms a semi-circle from lateral v

17、iew 3. axis of rotation 4. osteokinematic movements range of motion (ROM) 0-140 for knee flexion some for knee hyperextension closed kinematic chain motions deep squatting standing up from sitting stance phase of the gait cycle supine lying with the leg pushing against the wall 4. osteokinematic mov

18、ements functional range walking: 0-67 climbing stairs: 0-83 descending stairs: 0-90 sitting in a chair: 0-93 tying a shoe: 0-106 lifting an object from the floor: 0-117 functional range arthrokinematic movements tibiofemoral joint： concave on convex Tibia on FemurPatella on FemurMenisci relative to

19、tibiaKnee Flexionposterior glide inferior glideposterior displacementKnee Extensionanterior glidesuperior glideanterior displacementarthrokinematic movements Tib6. screw-home mechanism synonym： knee locking mechanism continuous inward rotation of the femur that accompanies the completion of knee ext

20、ension during the closed kinematic chain motions 6. screw-home mechanism 7. patellar tracking movement： dictated by quadriceps contraction medial/lateral shift： c-curve pattern from knee flexion to extension medial/lateral tilt： The patella tilts medially from knee flexion to extension, but the pate

21、lla is still in the laterally tilt position even the knee is in the fully extended position. 7. patellar tracking movement：8. factors checking knee flexion mass of the hamstrings passive tension of the quadriceps tension of the posterior cruciate ligament 8. factors checking knee fle9. factors check

22、ing knee extension bony contact passive tension of the hamstrings tension of the anterior cruciate ligament 9. factors checking knee exTibia inward and outward rotation only occurs in the knee flexed position and not indicate screw home mechanismjoint involved： tibiofemoral jointplane of motion： tra

23、nsverse planeaxis of rotation： vertical axis through or close to medial tibial intercondylar tublercle Tibia inward and outward rotat5. osteokinematic movements total range = 70-80 at 90 of knee flexion outward inward rotation no rotation at full extension 6. arthrokinematic movements： spin of the t

24、ibia on the femoral condyles menisci movements follow the motions of the femoral condyles 7. outward rotation is limited by the passive tension of the popliteus muscle 5. osteokinematic movements 第四节 Muscles Actions Around the Knee knee extensors knee flexors tibia inward rotators tibia outward rota

25、tors 第四节 Muscles Actions Around thKnee extensors1. quadriceps femoris rectus femoris： two-joint muscle knee extensor hip flexor vastus medialis vastus medialis longus vastus medialis obliquus vastus lateralis vastus intermedialis Knee extensors1. quadriceps fKnee extensors2. Efficiency of quadriceps

26、 depends on the patella 3. Maximum isometric force occurs at 60 of knee flexion 4. No quadriceps activity required to keep knee extension at erect stance 5. isokinetic strength： H/Q ratio= 0.7:1 Knee extensors2. Efficiency ofKnee flexors hamstrings： two-joint muslce biceps femoris semitendinosus sem

27、imembranosus sartorius （缝匠肌）Gracilis（股薄肌）Popliteus（腘肌）gastrocnemius： two-joint muslce Knee flexors hamstrings： two-jTibia inward rotation at 90 of knee flexionpopliteus： knee flexion + inward rotationSemitendinosussemimembranosus Tibia inward rotation at 90 o Tibia outward rotation at 90 of knee fle

28、xion biceps femoris Tibia outward rotation at 90第五节 Knee Stability factors affecting stability of the tibiofemoral joint Factors affecting stability of the patella 第五节 Knee Stability Factors affecting stability of the tibiofemoral joint 1. bony configuration： the least important 2. tension of ligame

29、nts or other connective tissues anterior cruciate ligament (ACL)： anteromedial stability prevent anterior displacement of the tibia posterior cruciate ligament (PCL)： anterolateral stability prevent posterior displacement of the tibia lateral collateral ligaments (LCL)： prevent varus stress medial c

30、ollateral ligament (MCL)： prevent valgus stress medial and lateral retinaculum iliotibial bandFactors affecting stability of3. passive tension of muscles： quadriceps femoris hamstrings pes anserinus3. passive tension of muscleFactors affecting patella stability1. bony configuration Prominent anterolateral asp