Musculoskel System Review Gait- (via O'sullivan)

Question 1

Describe the kinematic motion and internal forces occurring during Heel strike at each joint.

Answer 1

Hip: 20-40 deg hip flexion toward ext. Glute max and H/S working eccentrically to resist flex moment

Knee & and Tibia: In full ext before heel contact. Flexing as heel strikes floor. Tibia: slight lateral rotation. Quad femoris contracting eccentrically to control rapid knee flex and prevent knee buckling

Foot and Ankle: Foot= supination. Ankle= moving into PF. DF (tib ant. ext digitorium longus and EHL) contract eccentrically to slow PF.

SB: Peak activity just after heel strike PF.

Question 2

Describe Kinematic motion and internal forces occurring during Foot flat?

Answer 2

Hip: Moving into EXT, ADD, IR. Glute max and H/S concentrically to bring hip into Ext

Knee and Tibia: In 20 deg flex moving toward ext. Tib= Medial rotation. After foot is flat quad femoris activity becoming concentric to bring femur over tibia.

Foot & Ankle: Foot= pronation. Ankle: PF to DF over fixed foot. PF muscles activated to control DF of the tibia and fibula over a fixed foot, contracting eccentrically.

Question 3

Describe Kinematic motion and internal forces occurring during Midstance?

Answer 3

Hip: Moving through neutral position. Pelvis rotation post. Illiopsoas activity continuing.

Knee & Tibia: Knee= in 15 deg flex moving toward ext. Tibia= ER. Internal: Gastroc beginning to work concentrically to start knee flexion.

Foot and Ankle: Foot = Neutral. Ankle= 3 deg of DF. PF muscles activated to control DF of tibia and fibula over a fixed foot. Contracting ecccentrically

Question 4

Describe Kinematic motion and internal forces occurring during Toe-Off?

Answer 4

Hip: Moving Toward 10 deg Ext, ABD, ER. Internal: Adductor magnus working eccentrically to stabilize pelvis. Illiopsoas activity continuing.

Knee/Tibia: Moving from near full Ext to 40 deg flexion. Tibia ER. Internal: Quad femoris contracting eccentric.

Foot/Ankle: Foot= Supination. Ankle= 20 deg PF. Plantar flexor muscles at peak activity! become inactive as foot leaves ground.

Question 5

Describe Kinematic motion and internal forces occurring during Heel-Off? (O”sullivan only includes foot/ankle)

Answer 5

Foot/Ankle: Foot= Supination as foot becomes rigid for push off. Ankle= 15 deg DF toward PF. PF muscles contract concentrically to prepare for push off.

Question 6

Describe Kinematic motion and internal forces occurring during Acceleration to Midswing?

Answer 6

Hip:
Slight flex moving at 30 deg flexion and ER to neutral. Hip flexors working concentric to bring limb through. C/L Glute Med concentric to maintain neutral pelvis.

Knee:
30-60 knee Flx & ER of tibia moving toward neutral. H/S concentric

Ankle/Foot
20 deg DF and slight pronation. DF muscles concentric

Question 7

Describe Kinematic motion and internal forces occurring during Midswing to deceleration?

Answer 7

Hip:
Continued flx at about 30 to 40 deg. Glute max eccentric to slow hip flx.

Knee:
Moving to near full extension and slight ER of tibia. Quads concentric and H/S eccentric

Ankle/Foot:

Ankle in neutral foot in slight supination. DF muscles contracting isometrically.