GAIT ANALYSIS IN ELDERLY POPULATION

Presenters : Adil Ali Ansari & Deepanjali Sharma BPT 3rd year , Jamia Hamdard University February, 2016

GAIT• It’s a cyclical pattern of progression

of body from one place to another with an alternating & repeating placement of feet with a condition that atleast ¼ of the feet is in contact with the walking surface.

• Represents the progression of body’s COM along a horizontal trajectory in a certain direction with a certain velocity.

FACTORS AFFECTING LOCOMOTION IN ELDERLY• Loss of muscle mass, strength & power >in females(25-54% lower peak power & torque male lose 20% strength by 65 years• Decreased joint ROM • Decreased reaction time• Decreased acuity for auditory, vestibular , visual,

somatosensory system• Decreased cognition • Variation in stride parameters Velocity decreases with age( 0.1-0.7% per year) Decreased stride length & cadence Height a factor for decreased velocity Increase in stance time , double support & decreased stride symmetry

DIAGNOSES LEADING TO GAIT DISORDERS

• Frontal gait disorders(20-28%)• Sensory imbalance( 4-18%)• Myelopathy(16-24%)• Parkinsonism(9-12%)• Cerebral atrophy(8%)• Orthostatic hypotension( 2-9%)• Degenerative joint disease( 4-43%)• Alzheimer’s(4%)• Depression( 2%)

Neil Alexander,1996

JOINT KINETIC & KINEMATICS WITH INCREASING AGE

ANKLE JOINT Kinetics : Dec. PF moment & power, weak ankle PF & DF Reduced PF power affects ; Swing initiation Trunk progression Trunk stabilization

Kinematics : Dec. ROM (3024 degrees) Large “toe out” angle Chris A McGibbon,2003

KNEE JOINT

Kinetics : Dec. ROM Elderly have slight knee flexion at the end of swing (younger have full extension) dec. quadriceps demand for loading correlates with shorter step length

Kinematics : higher energy absorption b/w stance & swing( 1654%) OA knee reduces knee power & has greater increase in hip eccentric energy expenditure ( McGibbon 7 Krebs)

HIP JOINT

Kinetics : Increase in ROM Accommodates for increased hip extension with anterior pelvic drop

Kinematics : Compensations at hip produces concentric hip powers (active extension) angular impulse ( sum of all moments) d/t decreased muscle strength of ankle PF & knee quadriceps group / hip muscle contractures

Chris A McGibbon, 2003

Chris A McGibbon, 2003

OTHER CONSIDERATIONS…

• Lower A/P push off force

• Higher A/P & M/L acceleration >60years

• Energy cost of walking increases with age d/t multiple factors

• At maximum pace , elderly increases hip power but not ankle power ( in young peak power increases at each joint)

OTHER CONSIDERATIONS…

• Foot pressure Lower pressure at heel, midfoot, hallux (Morag , Cavanagh, 1999) Lower pressures on medial side, elderly bear weight on lateral side of foot ( Treadmill study, Hessert et al., 2005)

• Stair descent = Controlled fall More time spent in foot flat Greater M/L COG displacement & velocity Less foot clearance Less confidence = slower speed

OTHER CONSIDERATIONS…

• Falls Leading cause of accidental death >75 years By 2020, cost of fall related injuries will reach 32.4 billion Heel contact skid velocity higher ( 1.15m/s Vs 0.87m/s), even with slower cadence Delayed or prolonged muscle activation is the key element for unsafe gait (have increased electromechanical delay, time from EMG to force production) Greater lateral sway, increased threshold for movement detection Problems for compensating for absent or disrupted sensory information, use of assistive device Slower, more variable 1st step

STRATEGIES FOR OBSTACLE AVOIDANCE

• More rigid posture• Needed to compensate for decreased ability to control

upper• Torso movement • Increased variability = increased risk of obstacle contact• Increased limb elevation to clear foot• Psychosocial implications More depressed More anxious Greater fear of falling

GAIT ANALYSIS : TECHNIQUES

• Semi- subjective analysis techniques Timed 25-foot walk( T25-FW) Multiple sclerosis walking scale (MSWS-12) Tinetti Performance-Oriented Mobility Assessment (POMA) Timed Get up and Go (TUG) Gait Abnormality Rating Scale (GARS) Extra-Laboratory Gait Assessment Method (ELGAM)

• Objective gait analysis techniques Image processing, possible to obtain important elements of the image with a better & faster real time process -Stereoscopic vision -Time of flight (TOF) -Laser range scanner -Infra-red thermography(IRT)

Floor sensors Steps recognized, time elapsed in each position, profiles for heel and toe impact• Force platform AMTI series OR6-7 of Biometrics France • Kistler force plates of different types• Dynamometric mat ADAL of Tecmachine• MatScan System made by Tekscan (43.6 ×36.9 cm)• Walking mat made by RM.Lab (150 ×50 cm)• FootScan Plates made by RSScan.Lab (up to 200 ×40 cm)• FDM-T System for stance and gaits analysis made by Zebris (150 ×50 cm)

Flexi Force piezoresistive pressure sensor

Instrumented shoe with baro-podometric insoles Fig.1 a. inertial measurement unit b. flexible goniometer c. pressure sensors which are situated inside the insole

Fig.2 a. inertial sensor, Bluetooth, microcontroller and battery b. coil for inductive recharging c. pressure sensorsmodule

• Features of different gait analysis systems

• Comparison between NWS and WS systems

THANK YOU!...