Dr Alison Grimaldi's Hip course

Question 1

Intrapelvic Stability mechanisms

Answer 1

Key elements of pelvic control

1. optimal intrapelvic stability
2. Optimal control of femoral head in acetabulum
3. Optimal control of pelvis on femur

Active and passive stability systems

Passive stability systems

• bony structure
• ligamentous system
• Ligaments are not designed to maintain continous gravitational loads
• If you hold them in lengthened position - creep will allow them to lengthen
• Ligaments are good for controlling dynamic load, controlling end range movements, and additionally providing proprioceptive feedback

Active stabilisation

• consider role of TA and piriformis, iliacus (links into to TA) all provide deep support to the pelvis / SIJ
• we need good deep muscle activation ^^ to resist bifurcating forces of larger superficial muscles - w/o adiquate stability activation -> large amount of tortional force produced through pelvis

Question 2

Stability systems of the hip joint

Answer 2

Passive structures

1. Bony structure
2. Labrum

• Fibrocartilage structure
• keeps negative pressure in the joint space
• maintains fluid that absorbs loading so it’s not cartilage on cartilage

The role of the active system

• to help absorb and direct forces imposed on the joint

inadequate active stabilisation leads to

• excessive impact loading
• excessive shearing/translation
• impingement

which lead to joint damage and migratory patterns of wear

Consider postures - sway back with hips forwards enables anterior translation with loose anterior structures

Posterior migration - lordosis posture - tightness in anterior hip

Deep muscle system

• primary function controlling femoral head in acetabulum
• small torque production

Iliacus, iliocapsularis, glute min, obturator int/ext, quadratus femoris, gamelli superior and inferior

Intermediate muscle system

• significant role in torque production and control of the pelvis on femur in WB and lower load function
• Secondary stabilisers of femoral head and acetabulum
• Glute med, piriformis, short adductors ilipsoas

Superficial muscle system

1’ torque production musculature and control of femur in WB

Phasic contraction

if always turned on - injuries to structures below

• Glute max, TFL, Adductors, Rec Fem, Sartorius, HS

Dysplasia type 1

• acetabulum is shallow

smaller weight bearing surface

Hypermobility

Labral insufficency

movement patterns - w/ hip extension-> anteriorly directed hip forces incr -> anterior joint load with sway back posture

Question 3

Gluteus Maximus

Answer 3

Action:

Upper glute max . -primary abd and ER

Lower glute max - ext + abd and ER

Function during gait

start of stance controls adduction

end of swing

OA
- unilateral decrease in hip extensors 19%/22%

loss of muscle size

UGM Assymetry - hypertrophy in affected side

LGM fatty infiltrate and atrophy

TFL showed no differences even in advanced OA

Muscle unloading

Lower glute max is affected by unloading, upper glute max is not

Lower glute max atrophy may precede hip OA, just like quads atrophy precedes knee OA

Exercises for lower glute max

• glute bridges - avoiding hyperextension for anterior joint

Step ups

scooter

Question 4

The hip abductor complex

Question 5

External Rotators