Gait biomechanics
-
Upload
yumna-ali -
Category
Health & Medicine
-
view
124 -
download
3
Transcript of Gait biomechanics
![Page 1: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/1.jpg)
Gait And Gait Cycle
1
![Page 2: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/2.jpg)
Gait Normal Gait
Series of rhythmical , alternating movements of the trunk & limbs which result in the forward progression of the
center of gravity…
2
![Page 3: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/3.jpg)
Gait is style , manner or a pattern of walking.
Walking pattern may differ from individual to individual
3
![Page 4: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/4.jpg)
Gait Cycle
• Defined as the period of time from one heel strike to the next heel strike of the same limb
4
![Page 5: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/5.jpg)
Gait Cycle
The gait cycle consists of two phases…
1) STANCE PHASE2) SWING PHASE
5
![Page 6: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/6.jpg)
• Gait is style , manner or a pattern of walking.• Walking pattern may differ from individual to individual
6
![Page 7: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/7.jpg)
7
![Page 8: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/8.jpg)
8
![Page 9: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/9.jpg)
STANCE PHASE
Begins when the heel of one leg strikes the ground and ends when the toe of the same leg lifts off. Constitutes approximately 60% of
the gait cycle.
9
![Page 10: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/10.jpg)
10
![Page 11: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/11.jpg)
Swing phase represents the period between a toe off on one foot ad heel contact on the same foot.
Constitutes approximately 40%
of the gait cycle.
SWING PHASE
11
![Page 12: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/12.jpg)
12
![Page 13: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/13.jpg)
GAIT TERMINOLOGIESTime and distances are two basic
parameters of motion.
1. Temporal (Time) variables2. Distance (Spatial) variables
13
![Page 14: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/14.jpg)
TEMPORAL VARIABLES
1. Single limb support time2. Double support time3. Cadence4. Speed
14
![Page 15: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/15.jpg)
Amount of time that spent during the period when only one extremity is on the supporting surface is a gait cycle.
Single Limb Support Time
15
![Page 16: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/16.jpg)
Double Support TimeAmount of the time spent with both feet on the ground during one gait cycle. The time of double support may be
increased in elder patients and in those having balance disorders
The time of double support decreases when speed of walking increases
16
![Page 17: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/17.jpg)
17
![Page 18: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/18.jpg)
Distance Variables
1. Stride length2. Step length3. Degree of toe out
18
![Page 19: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/19.jpg)
Stride length
19
![Page 20: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/20.jpg)
Step length
20
![Page 21: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/21.jpg)
Degree of toe out It represents the angle of foot placement and may be found by measuring the angle formed by each foot’s line of progression and a line intersecting the center of heel and second toe.The angle for men is about 7 degree.the degree of toe out decreases as the speed of walking increases in normal men.
21
![Page 22: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/22.jpg)
22
![Page 23: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/23.jpg)
KINEMATICS AND KINETICS OF GAIT
• Path of Center of Gravity – midway between the hips– Few cm in front of S2– Least energy consumption
if CG travels in straight line
![Page 24: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/24.jpg)
Path of Center of Gravity
![Page 25: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/25.jpg)
Path of Center of Gravity
![Page 26: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/26.jpg)
HEEL STRIKE TO FOOT FLAT• Heel strike to forefoot loading • Foot pronates at subtalar joint• Only time (stance phase) normal
pronation occurs• This absorbs shock & adapts foot to
uneven surfaces• Ground reaction forces peak• Leg is internally rotating• Ends with metatarsal heads
contacting ground
![Page 27: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/27.jpg)
![Page 28: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/28.jpg)
![Page 29: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/29.jpg)
FOOT FLAT TO MIDSTANCE
![Page 30: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/30.jpg)
MIDSTANCE TO HEEL OFF
![Page 31: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/31.jpg)
HEEL OFF TO TOE OFF
![Page 32: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/32.jpg)
DETERMINANTS OF GAIT • Six optimizations used to minimize excursion of
CG in vertical & horizontal planes• Reduce significantly energy consumption of
ambulation• The six determinants are Lateral pelvis tilt Knee flexion Knee, ankle and foot interactions Forward and backward rotation of pelvis Physiological valgus of knee
![Page 33: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/33.jpg)
DETERMINANTS OF GAIT
1) Pelvic rotation:– Forward rotation of the pelvis in the horizontal
plane approx. 8o on the swing-phase side– Reduces the angle of hip flexion & extension– Enables a slightly longer step-length w/o further
lowering of CG
![Page 34: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/34.jpg)
(2) Pelvic tilt:– 5 degree dip of the swinging side (i.e. hip
adduction)– In standing, this dip is a positive Trendelenberg sign– Reduces the height of the apex of the curve of CG
![Page 35: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/35.jpg)
(3) Knee flexion in stance phase:– Approx. 20o dip– Shortens the leg in the middle of stance phase– Reduces the height of the apex of the curve of
CG
![Page 36: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/36.jpg)
(4) Ankle mechanism:– Lengthens the leg at heel contact– Smoothens the curve of CG– Reduces the lowering of CG
![Page 37: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/37.jpg)
• Physiological valgus of knee Reduces the base of support, so only little lateral
motion of pelvis is necessary.
![Page 38: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/38.jpg)
RUNNING GAIT• Require greater balance, muscle strength,
ROM than normal walking.• Difference b/w running and walking• Reduced BOS• Absence of double support• More coordination and strength needed• Muscle must generate higher energy bout
to raise HAT higher than in normal walking.
• Divided into flight and support phase.
![Page 39: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/39.jpg)
39
![Page 40: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/40.jpg)
STAIR GAIT
• Ascending and descending stairs is a basic body movement required for ADL
• Stair gait involved stance and swing phase
![Page 41: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/41.jpg)
kinematics
• SWING PHASE(36%)
• Foot clearance • Foot placement
• STANCE PHASE(64%)
• Weight acceptance • Pull up• Forward continuance
![Page 42: Gait biomechanics](https://reader035.fdocuments.us/reader035/viewer/2022081503/58f260e41a28ab20468b4631/html5/thumbnails/42.jpg)