1. Pathomechanics of Gait and Dynamic Postures part 2
Dr .Manal Radwan Salim
Lecturer of Physical Therapy
Pharos University

2. Determinants of Gait Cont. :
(2) Pelvic Tilt:
5o dip of the swinging side (i.e. hip adduction) maximum tilt is in mid swing
Advantage: Reduces the height of the apex of the curve of COG by 3/8 inch
Pathologically: Pelvis dip increase downward of swing side by weakness of abductors of stance limb. , or even pelvis raised up in swing in any problem leads to functional lengthening the swing limb.

3. Determinants of Gait Cont.:
(3) Knee flexion in stance phase:
in Loading response, midstance
Shortens the leg in the middle of stance phase
Advantage: Reduces the height of the apex of the curve of COG
Pathologically: flexion degree may increases (shorter stance than usual so gives apparent longer swing
Or there is limitation in flexion (longer stanced limb i.e affected give problems in other leg stance?!)

4. Determinants of Gait Cont.:
(4) Ankle Mechanism:
lengthens the leg at heel contact
Advantages: a)Smoothens the curve of COG
b)Reduces the lowering of COG

5. Determinants of Gait Cont. :
(5) Foot mechanism:
While knee is flexed the leg is lengthened at toe-off as ankle moves from dorsi flexion to plantar flexion
Advantages: a) Smoothens the curve of COG
b) Reduces the lowering of COG

6. Determinants of Gait Cont. :
(6) Lateral displacement of body:
The COG is displaced laterally over the weight bearing extremity twice during gait cycle( the motion produced by horizontal shift of pelvis and relative adduction of hip (max at mid stance).

7. Weakness in G. Max.: Appears in
Gluteus Maximus
Gluteus maximus shows peak activity in
IC, LR (i.e. weight acceptance), and
TS, some activity in PS( weight release).
Weakness in G. Max.: Appears in
Early stance: IC, IC-LR).
G. Max. contract to prevent jack-knifing i.e. excessive hip flexion) and anterior pelvic tilt.
N. Path. GRFV IC
A to hip LR

8. Gluteus Maximus Cont.
Possible Compensation Patient leans trunk backward (so moves GRFV backward).
This is called gluteus maximus gait or Lurch gait
From this we can notice that: If bilateral weakness so The gluteus maximus lurch appears in both early and late stance phases of rt limb and lt limb. If unilateral (rt) so it appears in early stance of rt > in late stance of lt

9. Hip Flexors
In stance its activity starts at terminal stance to preswing and increases to initiate swing .
Effect of weakness Toe may not clear the floor during swing “Toe Drag”.
Compensation:
-circumduction at hip.
-Pelvic Hike

10. Quadriceps In Early stance: Quad. contracts to prevent
Quadriceps shows peak activity in LR (i.e. weight acceptance). Some activity in TS and PS (weight release).
In Early stance: Quad. contracts to prevent
jack-knifing of knee.
Possible Compensation: Patient leans trunk forward (GRFV
moves anterior).
2-Pt use arm as quadriceps by placing hand anterior to thigh,
presses knee backward.
N. Path. GRFV LR
P. To knee
3-Turn limb outward to lock knee passively.

11. Quadriceps Cont. In Early stance Cont.: In Late stance:
4- Contact ground with flat planter flexed foot so GRFV moves anterior.
5-place a shoe or cushion under heel which causes GRFV to move anteriorly.
In Late stance:
Quad. contracts to control knee flexion
So in case of weakness the knee collapse into flexion leading to -premature flexion into early swing-‘rubber knee’
N. Path. GRFV PS
P to knee

12. Hamstrings
In stance: It show little activity, support back of knee against extension moment of GRFV.
In swing: *Assist knee flexion in IS. *Decelerates tibial shank in TS
Weakness in Hamstrings:
In Swing: 1- Inadequate knee flexion.
Late Swing: 2-Lack of control of swinging leg
3- Knee slapped into extension.
In Stance: 4-Reduction of restraining force of heel strike.
5-Progressive Genu Recarvatum.
Compensation:
1- Increased hip flexion in swing
2- Circumduction in swing hip
3- Hiking with swing pelvis

13. Possible causes When in gait cycle description Gait type Spasticity in
Limited ROM, pain , …..
Weakness in
in early stance
Lean trunk backward
G. maximus lurch
or spasticity in quadriceps or planter flexors
Flexion of hip, knee or ankle
h. Flex, hamstring, dorsiflexors
swing
Toe drag
Hip flexors, hamstring
circumduction
Pelvis hiking

14. Possible compensations
manifestation
When in Gait cycle
problem
Outward rotate leg to lock it passively
Place hand in early stance to push knee backward
Lean trunk forward in stance
Jack Knifing of knee IC
Quad weakness
place a shoe or cushion under heel so GRFV moves anteriorly.
IC with flat planter flexed foot so GRFV moves anterior.
Pelvis hiking
Circumduction
Incresed hip flexion in swing
Progressive Genu Recarvatum
Mid stance
Hamstring weakness
Reduction of restraining force
of heel strike
Knee slapped into extension
deceleration
Increased hip flexion
midswing

15. Pre-Tibial group
Ankle dorsi flexors shows peak activity in IC, LR (i.e. weight acceptance).
Weakness in DF appears in
a) Early stance: IC, IC-LR).
DF Contract to control forefoot lowering. After forefoot contacts floor- pull tibia forward over foot.
N. Path. GRFV IC
P to ankle LR

16. Pre-Tibial group Cont. Compensation: ‘high steppage gait’
b) Swing phase:
DF contract concentrically in swing sub phases 1- to lift toe up so prevent toes from dragging on ground.
2- functionally shorten swinging limb.
Compensation:
In stance: no compensation what happen is forefoot slaps to the floor ‘drop-foot’ gait
In Swing: 1-Increased hip flexion
‘high steppage gait’
2- Circumduction at hip.

17. Plantar Flexors (Calf muscle)
Calf activity in TS and PS, some activity in MS
Weakness in calfs appears in late stancemuscles show peak : as it controls dorsi flexion degree in MS and TS ecentrically.
N. Path. GRFV
A. To Ankle MS TS PS
Then contract concentrically to planter
flex ankle joint in PS.
Effect of Weakness:
Loss of forward thrust - poor transition to early swing

18. Plantar Flexors (calf muscle) Cont.
Possible Compensation: 1- Outward rotate hips and pronate foot so inner border contact the ground (flat foot gait or calcaneal gait) 2-Ankle maintained in planter flexion in mid stance to avoid excessive dorsi-flexion ?! (passively by genu recarvatum). 3-Maintain foot flat in TS to eliminate dorsi-flexion moment.

19. Hip Abductors Gluteus Medius
G. Medius contract in mid stance to prevent contra-lateral (swinging) hip from dipping greater than 5 – 80
Effect of weakness/absence
Contra-lateral hip drops > 5-80
Compensation is to lean (‘lurch’) over stance-side LE
N. Path. of GRFV LR MS Ts
Medial to to hip

20. COMMON GAIT ABNORMALITIES
A. Antalgic Gait.
B. Lateral Trunk bending.
C. Functional Leg-Length Discrepancy.
D. Increased Walking Base.
E. Inadequate Dorsi flexion Control.
F. Excessive Knee Extension.

21. COMMON GAIT ABNORMALITIES Cont.: A. Antalgic Gait
-Gait pattern in which stance phase on affected side is shortened
-Corresponding increase in stance on unaffected side
-Common causes: OA, tendinitis

22. Usually unilateral, if Bilateral = waddling gait Common causes:
COMMON GAIT ABNORMALITIES cont.: B. Lateral Trunk bending’Trendelenberg gait
Usually unilateral, if Bilateral = waddling gait
Common causes:
A. Painful hip B. Hip abductor weakness
C. Leg-length discrepancy D. Abnormal hip joint

23. COMMON GAIT ABNORMALITIES Cont.: C. Functional Leg-Length Discrepancy
Swing leg: longer than stance leg:
Causes dicussed in details in muscle weakness
4 common compensations:
A. Circumduction
B. Hip hiking
C. Steppage
D. Vaulting

24. COMMON GAIT ABNORMALITIES Cont.: D. Increased Walking Base
Normal walking base: 5-10 cm
Common causes:
Deformities
Abducted hip
Valgus knee
Instability
Cerebellar ataxia
Proprioception deficits

25. COMMON GAIT ABNORMALITIES Cont.: E. Inadequate Dorsiflexion Control
In stance phase (Heel contact – Foot flat):
Foot slap
In swing phase (mid-swing):
Toe drag
Causes:
Weak Tibialis Ant.
Spastic plantarflexors

26. COMMON GAIT ABNORMALITIES: F. Excessive knee extension
Loss of normal knee flexion during stance phase
Knee may go into hyperextension
Genu recurvatum: hyperextension deformity of knee
Common causes:
Quadriceps weakness (mid-stance)
Quadriceps spasticity (mid-stance)
Knee flexor weakness (end-stance)
* * *

27. Gait in the Elderly Men - Murray, Kory & Clarkson
Gait was guarded and restrained - attempt to maximal stability and security

28. Gait in the Elderly Men - Murray, Kory & Clarkson
Gait resembled someone walking on a slippery surface
decreased step & stride legnth
wider dynamic BOS
increased lateral head movement
decreased rotation of pelvis

29. Gait in the Elderly Men - Murray, Kory & Clarkson
toe/floor clearance distance slightly decreased
lower stance-to-swing ratio
decreased reciprocal arm swing more from elbow than shoulder

30. Spasticity and its Impact on Gait
Spasticity - resistance to passive stretch

31. Spasticity & Gait Effects: Restrict joint excursion
Delay transition from one gait phase to the next

32. Spasticity & Gait Examples
Quadcriceps
May prevent knee from unlocking during interim between HS and FF
Knee maintained in extension leading to a ‘vaulting’ over stance limb or circumduction of hip
Disrupts (timing) transition to mid- and late stance
May prevent LE bending during swing phase

33. Spasticity & Gait Examples
Plantar flexors
Increase in spastic tone may limit forward rotation of tibia between MS and PO
May locate ground reaction force well behind knee causing significant flexion moment during late MS and knee buckling tendency
Ankle may be locked up during PO decreasing propulsive thrust forward - inefficient transition from TO to early swing

34. Spasticity & Gait Examples
Hamstrings
May limit forward swing of LE - decreasing step length
May prevent knee from reaching a terminally extended position just prior to HS

35. Pathway of GRFV during gait in sagital and frontal plane
Stance
Phases
Sagital
HIP Joint
Knee Joint
Ankle Joint
Frontal
Heel Strike A L P N
Foot Flat M
Mid Stance
Heel Off
Toe Off