bio mechanics of gait
Post on 12-Nov-2014
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Mark David S. Basco, PTRPFacultyDepartment of Physical TherapyCollege of Allied Medical ProfessionsUniversity of the Philippines Manila
At the end of the session, you should be able to:
Explain the importance of studying gait in PT and OT
Identify fundamental requirements of normal gait
Define the phases and sub-phases of gait and tasks accomplished by these
At the end of the session, you should be able to:
Describe gait in terms of kinematic and kinetic variables
Explain the “determinants” of gait Describe changes in aging Describe effects of common pathological
conditions on gait
Appreciation of our own locomotor ability Knowledge of gait is important in
understanding human function Knowledge of gait can aid in identifying
abnormalities and, thus, care needs of patients in PT and OT
Equilibrium and Locomotion
Others◦ Intact musculoskeletal system◦ Normal muscle tone◦ Intact sensory system
Tasks accomplished by gait Gait cycle:
◦ Phases◦ Sub-phases
Time and distance parameters of gait Relationships among gait variables
Tasks accomplished by gait Weight acceptance Single limb support Limb advancement
Gait cycle phases Gait cycle, stride, step Stance
◦ Single limb support (SLS)◦ Double limb support (DLS)
Swing
Gait cycle sub-phases (STANCE) Initial contact Loading response Midstance Terminal stance Preswing
Initial contact
Loading response
Midstance
Terminal stance
Preswing
Gait cycle sub-phases (SWING) Initial swing Midswing Terminal swing
Initial swing
Midswing
Terminal swing
Traditional terminology◦ Heel strike (HS)◦ Foot flat (FF)◦ Midstance (MSt)◦ Heel off (HO)◦ Toe off (TO)
Traditional terminology◦ Acceleration (Acc)◦ Midswing (MSw)◦ Deceleration (Dec)
Time and distance gait variables Stride length and stride time Step length and step time Stance time and swing time SLS time and DLS time Base / step width
Time and distance gait variables Foot angle Gait velocity: free, fast, slow Cadence Period of “double float”
Relationships among some variables Gait velocity and cadence Gait velocity and step length Gait velocity and SLS time Gait velocity and DLS time
The equivalent of heel strike in the Rancho Los Amigos terminogy is:
A. Initial contact
B. Loading response
C. Preswing
D. Initial swing
This sub-phase of stance occurs from the time the contralateral foot gets into contact with the ground until the reference foot lifts off the ground:
A. Terminal stance
B. Preswing
C. Loading response
D. None of the above
With an increase in gait velocity, the following will increase logically, EXCEPT:
A. Cadence
B. Step length
C. DLS time
D. None of the above
Description of joint motions that occur during gait
Ideally, description should encompass all three planes of motion
Often, sagittal motions are described (simplistically)
HS – FF 0 – 15 deg p/flex
FF – MSt 15 deg p/flex – 10 deg d/flex
MSt – HO 10 – 15 deg d/flex
HO – TO 15 deg d/flex –20 deg p/flex
O’ Sullivan, S.B., & Schmitz, T.J. (2001). Physical rehabilitation: Assessment & treatment. Philadelphia; F.A. Davis.
Acc – MSw d/flex - neutral
MSw – Dec neutral
O’ Sullivan, S.B., & Schmitz, T.J. (2001). Physical rehabilitation: Assessment & treatment. Philadelphia; F.A. Davis.
HS – FF 0 – 15 deg flex
FF – MSt 15 deg flex – 5 deg flex
MSt – HO 5 deg flex - neutral
HO – TO 0 – 40 deg flex
O’ Sullivan, S.B., & Schmitz, T.J. (2001). Physical rehabilitation: Assessment & treatment. Philadelphia; F.A. Davis.
Acc – MSw 40 – 60 flex
MSw 60 deg flex – 30 deg flex
Dec 30 deg flex - neutral
O’ Sullivan, S.B., & Schmitz, T.J. (2001). Physical rehabilitation: Assessment & treatment. Philadelphia; F.A. Davis.
HS – FF 30 deg flex
FF – MSt 30 – 5 deg flex
MSt – HO-TO 5 deg flex - 10 deg ext
Acc - MSw 20 – 30 deg flex
MSw – Dec 30 deg flex
O’ Sullivan, S.B., & Schmitz, T.J. (2001). Physical rehabilitation: Assessment & treatment. Philadelphia; F.A. Davis.
At the moment of HS, the ankle is normally in this many degrees of dorsiflexion:
A. 20
B. 10
C. 5
D. None of the above
Using traditional terminology, the highest amount of knee flexion during normal (comfortable) gait is observed in:
A. Toe off
B. Acceleration
C. Midswing
D. Deceleration
Normally, the hip must extend to at least this many degrees during HO – TO to aid limb advancement:
A. 10
B. 20
C. 30
Ground reaction forces
Electromyographic activity
Ankle dorsiflexors Just after initial contact
Swing phase
Ankle plantarflexors Loading response
Preswing
Knee extensors Loading response
Preswing (slight)◦ Rectus femoris
Knee flexors Terminal swing to initial contact
Initial swing
Hip extensors Terminal swing to initial contact
Hip flexors Initial swing
Hip abductors Loading response through midstance
Hip adductors Preswing ; Initial swing
Back extensors At initial contact (both sides)
Peak activity of the knee extensors occur in:
A. Loading response
B. Midstance
C. Terminal stance
D. Preswing
At initial contact, the erector spinae on both sides are active to check:
A. Trunk flexion
B. Trunk lateral flexion
C. Hip flexion
D. None of the above
Intuitively, peak activity of the ankle plantarflexors should occur in:
A. Initial contact
B. Loading response
C. Terminal stance
D. Preswing
Reduce maximum COM height of the body during midstance
Increase minimum COM height of the body at heel-strike and toe-off
Pelvic rotation Pelvic obliquity or “list” Knee flexion in the stance phase Ankle rockers Transverse rotation Genu valgum
Pelvic rotation
Pelvic obliquity or “list”
Knee flexion in the stance phase
Ankle rockers
Ankle rockers
Transverse rotation (1)
Transverse rotation (2)
Genu valgum
Gender; age Sensory conditions Demands / purpose of the task Environmental constraints Mood / psychological state
Dimensions of mobility (Patla & Shumway-Cook 1999)
Post-OTPT102 exam: which one represents you?
Physiological decline of multiple systems in the body
Effects of chronic conditions
Effects of acute conditions
Common observable changes* Decreased:
◦ GAIT velocity◦ STEP length◦ Arm swing◦ PELVIC rotation◦ ANKLE motions
Common observable changes* Increased:
◦ Cadence◦ DLS time◦ Postural sway
The COM of the body normally translates a total of ____ cm in the coronal plane:
A. 2
B. 4
C. 6
D. None of the above
Gait changes observed in aging is / are considered to be primarily a function of:
A. Acute health conditions
B. Chronic health conditions
C. Normal decline of physiological functions
D. All of the above
Common causes of abnormal gait Pain Muscle weakness Soft tissue or contracture Abnormal muscle tone
Common causes of abnormal gait Lower limb length discrepancy Impaired proprioception / kinesthesia Impaired balance or motor control
Some patterns of abnormal gait Antalgic gait Equinus gait Stiff knee gait Waddling gait
Some patterns of abnormal gait Hemiplegic gait Parkinsonian gait Scissors gait Ataxic gait
This abnormal gait pattern typically results when there is generalized muscle weakness in one side of the body:
A. Antalgic
B. Hemiplegic
C. Equinus
D. None of the above
In an antalgic gait pattern, the following would be expected to decrease, EXCEPT:
A. SLS time – affected limb
B. DLS time
C. Preswing – affected limb
D. None of the above
Generalized reflex hyperactivity of the lower limb muscles, the hip adductors in particular, often result in this abnormal gait pattern:
A. Equinus
B. Parkinsonian
C. Ataxic
D. None of the above
EACH GROUP must bring: Kinesiology attire 2 – 3 ink markers Masking tape Measuring tape Stopwatch 1m x 6m walkway Pair of sunglasses Piece of wood Small pebble
Gait is a complicated subject to learn and study. It is strongly encouraged that you do extra reading. For references that you
could use, do not hesitate to seek consult.
I would like to acknowledge Prof. EJ Gorgon, MPhysio, PTRP for the powerpoint slides used in this
presentation.
The depth and quality of learning that you would get from this college does not entirely depend on the faculty and the instructional materials used...
Most of it depends...
On the passion that you put into learning and your perseverance to rise up against the challenges and difficulties you would encounter.
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