Amir H. BakhtiaryPhD, PT

Associate Professor

Physiotherapy DepartmentRehabilitation faculty

Semnan University of Medical Sciences

Hip Joint Kinesiology

Weight distribution on the Hip Joint

Trabecular sysem

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WB in Hip Joint• Structures Specialized for WB

• Congruence surfaces• Organized Trabecular system

• Pelvic Upper trabecular• Pelvic Middle Trabecular• Pelvic Lower Trabecular• Femoral Lateral Trabecular• Femoral Medial Trabecular • Accessory trabecular system

− Lateral intertrochantric− Medial intertrochantric

Compressive and Tensile

Force resulting from bending

stress

The role of trabecular system to control forces?• Resistance against compressive Force

• Medial side of shaft (Medial trabecular)• Inferior part of Neck (Lateral trabecular)

• Resistance against Tractional Force• Lateral Side of Shaft (lateral trabecular)• Upper part of Neck (Medial trabecular)

• Resistance against Shear Stress

در حد فاصله بین سیستمها ترابکوالی اصلی و فرعی منطقه ای وجود دارد که ضعیف

بوده و اکثرا شکستگی های گردن فمور در این منطقه رخ می دهد

Describe the Arthrokiematic motion• Head of Femur move in opposite direction of the

limb • During Flex/Ext, the head Roll Post/Ant • During Abd/Add, the head Roll and Glide down/up• During Med/Lat Rot, the head Roll and Glide Post/Ant

Osteokinematics movements of femur at hip• Is defined based on:

• Active and Passive movements• Increased of tension in two-joints muscles

• Hip Flexion• 90 degree with knee extension• 120 degree with flexed knee

• Hip Extension• 10-30 degree with extended knee• Decrease with flexed knee

• Hip Abduction• 45 degree which decreased by Gracilis

• Hip Adduction• 20-30 degree which decreased by TFL and ITB

• Medial and Lateral rotation• 42-50 degree• Lateral rotation may decreased by anteversion angle

Describe the Osteokiematic motion

Hip Joint Motion for ADL Tasks

• The ROM needed to walk on the ground• 30 degree Flex and 10 degree Ext• 5 degree Abd and 5 degree Add• 5 degree in each Med/Lat Rot

• More ROM needed to walk on stairs• The movement is reverse in Closed Kinematic

Chain• Movement in Pelvic

Pelvic Movements in the Hip joint

• Reverse level• Ant (flex) & Post (Ext) Tilt

• Coronal Axes• Sagittal plane

• Lateral Pelvic Tilt• Abd in one leg and Add in another leg• Ant-post Axis• Frontal plane

Pelvic References position•Both ASIS in Horizontal•ASIS and Pobis in

Vertical

Lateral Pelvic Tilting

Lateral Pelvic Tilting

Lateral Pelvic Tilting in Bilateral Standing

Pelvic Rotation• Rotation of Pelvic in transverse Plane• Around the vertical axis, passes from the middle of

both pelvic in bilateral standing• Important of this movement is during unilateral

standing and Walking• Forward Rotation in the opposite WB leg

• Med Rot of WB leg

• Back ward Rotation in the Opposite WB leg• Lat Rot of WB leg

Pelvic Rotation

What is the Co-ordinated Movements in the lumbar, pelvic and femur?• Open Chain movement of pelvic

• Head and trunk move with pelvic in space• Forward bending to take some thing from

ground• Increase ROM

• Trunk• Lower limb

• Closed Chain movement of pelvic• Pelvic move alone against lumbar• Increase or decrease lordosis

Lumbar Pelvic Tilting in an Open Chain Movement

Lumbar Pelvic Tilting in an Open Chain Movement

Open Chain and Closed Chain Movement in Pelvic Lumbar Rhythm

Open Chain need Ankle Joint Plantar Flexion to

adjust LOG

How Hip Joint will be a part of a Closed Chain?• In bilateral standing head will be stable and direct

• Labyrinth Tonic Reflex• Visual correction

• Adjacent joints perform compensatory movement• To correct the position such as

• A short leg (eg Right leg)− Drop the pelvic in right side− Left lateral flex in lumbar

• Rise a leg from ground (eg right leg)− Drop the pelvic in left side− Right lateral flex in lumbar

Pelvic, hip and Lumbar spine Relationship

Some facts about Hip Lateral rotators

• Attach to femur in vertical direction• Press the head of femur to acetabulum

• Their action line is parallel to the neck of femur• They are ideal to stabilize head and neck of femur

• Their efficiency for Lat Rot reduce by hip flexion

Some Facts about Hip Medial Rotators

• There is no Special med rotator muscles• Every muscles that its line of action is in front of

joint work as Med Rot in some ROM • More important muscles in this part are

• G Med and• TFL

• The Medial Rotator Torque increases by hip flexion (3 times more than Lat Rot)• Lat rotator torque decrease by hip flexion