9. The Hip PDF

TOPIC 9: HIP JOINT Hip joint/Femoroacetabular joint Synovial “Ball and socket” joint 3 degree of freedom: Flex/Ext, ABD/ADD, IR/ER Function Support load of head, arms & trunk Force transmission Locomotion Works in Non-weight bearing (NWB) during Open Kinematic Chain movement...

TOPIC 9: HIP JOINT Hip joint/Femoroacetabular joint Synovial “Ball and socket” joint 3 degree of freedom: Flex/Ext, ABD/ADD, IR/ER Function Support load of head, arms & trunk Force transmission Locomotion Works in Non-weight bearing (NWB) during Open Kinematic Chain movements, and also in Weight bearing during Closed Kinematic Chain movements. Acetabulum Head of the femur articulates with the acetabulum. Acetabulum is normally directed laterally, anteriorly and inferiorly This creates the Hip joint. Acetabular labrum - increases congruence Transverse acetabular ligament Anatomical Variations and influence in the movement The angle o finalisation between the neck and the shaft of the femur can vary between human. A) Normal 120-125 B) Coxa Vara 105 C) Coxa Valga 140 The changes in the angle of inclination of the head of the femur can influence movement. Hip joint stability Static stabilizers (Passive structures): -Acetabular Labrum & transverse acetabular ligament. -Strong capsule -Ligaments: Iliofemoral, Pubofemoral, Ischiofemoral, Ligamentum Teres Dynamic stabilizers: muscles and myofascial tissue Acetabular Labrum Wedge-shaped fibrocartilage Serves to deepen the socket and icnreases the concavity of the acetabulum. Hip joint more stable than shoulder joint due to depth of the acetabulum # Ligamentum teres Directly connects head of femur to acetabulum. Also called “ligament of head of femur”. Provides stability, proprioception & coordination Important vascular supply to hip Osteokinematics of the hip Arthrokinematics Open kinetic chain. Femoral head moves on acetabulum. Femur = CONVEX Roll & Glide: opposite directions! Flexion: femur spins posterior with posterior pelvic tilt Extension: femur spins anterior with anterior pelvic tilt Kinetics of Flexion: Myology Anterior muscles Psoas/iliacus Rectus Femoris Sartorius TFL Kinetics of the Extension Myology Posterior muscles Gluteus maximus Gluteus Medius, Gluteus minimus Piriformis Semitendinosus Semimembranosus Biceps Femoris Limits for Flexion and Extension Limits of Flexion -Knee in Extension: posterior chain softy tissue tension -Knee in Flexion: structural-hit of the knee with the chest Limits of Extension -Iliofemoral ligament -Anterior chain soft tissue tension Arthrokinematics of the hip Open kinematic Chain. Femoral head moves on acetabulum. Femur = CONVEX ABD- ADD Abduction: Femur rolls superior and glides inferior Adduction: Femur rolls inferior and glides superior Limits for ABD and ADD Limits of abduction -Soft tissue tension from adductor muscles -Pubofemoral and Iliofemoral ligaments -Articular limitation Limits for adduction -Iliofemoral ligament Kinetics of Hip Abduction Primary motor muscles -Gluteus medius -TFL Secondary motor muscles -Gluteus minimus -Piriformis -Gluteus maximus -Obturator Externus and Gemellous superior and inferior -Sartorius Kinetics of Hip Adduction Primary motor muscles -Adductor Magnus -Adductor Longus -Adductor Brevis -Gracilis Secondary motor muscles -Quadratus femoris -Obturator Externus and Obturator internus Arthrokinematics of the hip Internal rotation: Rolls anterior and glides posterior External rotation: Rolls posterior and glides anterior Kinetics of ER Primary motor muscles Piriformis Obturator externus and internus Gemellous superior and inferior Quadratus femoris Secondary motor muscles Gluteus Maximus Posterior fibers of gluteus medius Kinetics of IR Primary motor muscles Adductor Magnus Adductor longus Adductor brevis Secondary motor muscles TFL Gluteus minimus Gluteus medius Pectineus Limits of External and Internal Rotation External rotation Iliofemoral and pubofemoral ligament tension Internal rotation Ischiofemoral ligament tension Tension of the external rotator muscles that by their depth and tone act as active ligaments. Arthrokinematics of the hip OKC