Università degli Studi di Roma “La Sapienza”Dipartimento di Meccanica e Aeronautica

Comparison between behaviours of young and elder subjects during a

Functional Reach testLucilla Monteleone, Stefano Pettinelli, Roberto Steindler

Functional Reach Test

• Functional Reach: is the maximal distance one can reach forward beyond prevalent arm lenght, while mantaining a fixed base of support in a a standing position

• Test start: right angle with the trunk

• Correct test: the clenched fist must be mantained at the same height; the heel must not rise

• Functional Reach can put in evidence muscolar-skeletal or neurological problems

• These problems change the ability in mantaining equilibrium• The test runs varing normal posture• The movement during the test is natural and istinctive

Importance of the test

Facilities

• A tape is used to misure the Functional Reach

• A p-mat is used to control the test (the heels do not rise)

• From the p-map acquisitions the CoP trajectory and its components can be plotted

The p-mat sensor

Conductive strips

velostat

kapton

kapton

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kapton

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velostatContact

resistencesLateral view

Sensor of 80x80=6400 sensing elements Dimentions: 40x40 cm2

Thickness:150 mRange: 400 – 500 kPaNo hysteresisNo response delay

The p-mat sensor and the chain measurement characteristics

Acquisition rate: 20 maps/sResolution: 12 bit

Parameters acquired during Functional Reach test

• CoP displacement in the test direction - CoP [cm]

• Functional Reach displacement – FR [cm]

Plantar pressure acquisition with p-mat

X-CoP(t) and Y-CoP(t)

• Test lenght: 15 s

• Subjects stands upright 5 s

• Functional Reach movement

• Waiting upright

stabilogram

Posterior movement

Anterior movement

The most of the tested subjects load more the prevalent leg

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Trend of Xb and Yb

Functional Reach test - execution

• Tested populations20 young healthy subject ; 10 males and 10 females; medium age: 22,3 ± 2,1 years14 elder healthy subjects ; 11 males and 3 females; medium age 61,5 ± 3,8 years

• All the subjects are healthy (no orthopedic or neurological problems) and they can mantain upright position at least 10 minutes

• All subjects have given their approval• Each subject runs three tests at natural speed and three tests at

maximum speed allowed by his status• The resuslts of each subject (Functional Reach and CoP in the two

conditions), come from the means of three acquisitions

Results

FR natural speed

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CoP natural speed

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CoP young CoP elder

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CoP maximum speed

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CoP young CoP elder

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FR young FR elder

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About resultsFR young: natural speed 35,6 ± 3,5 cm; max speed 35,0 ± 3,5 cm

FR elder: natural speed 31,0 ± 4,3 cm; max speed 28,9 ± 2,6 cm

CoP young: natural speed 7,0 ± 1,7 cm; max speed 7,4 ± 1,5 cm

CoP elder: natural speed 5,1 ± 1,5 cm; max speed 5,1 ± 1,1 cm

• Functional Reach decreases from young to elder population both at natural and maximum speed; the decrease significance is 99%

• Also CoP displacements decreases from young to elder population both at natural and maximum speed; also in this case the decrease significance is 99%

• Functional Reach decreases for both population from natural to maximum speed; the decrease, comes from requirement of going back as soon as possible to the upright position

CoP displacement shows a light increase from natural to maximum speed; the increase means a grater effort in mantaining equilibrium

Gender influence in young subjects10 males and 10 females

FR nat

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CoP nat

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males females

FR natural speed: Males: 36,5 ± 3,6 cm ; Females: 24,7 ± 3,2 cmFR max speed: Males: 36,2 ± 3,9 cm ; Females: 33,8 ± 2,6 cmCoP natural speed: Males: 7,8 ± 1,9 cm ; Females: 6,2 ± 1,0 cmCoP max speed: Males: 8,0 ± 1,5 cm ; Females: 6,9 ± 1,3 cm

• Functional Reach and CoP displacement of females are inferior of those of males but the differences are not significative

About gender influence

Gender influences in elder subjects11 males and 3 females

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CoP nat

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FR natural speed: Males: 31,4 ± 4,5 cm ; Females: 29,6 ± 4,0 cmFR max speed: Males: 28,9 ± 2,8 cm ; Females: 28,6 ± 2,2 cmCoP natural speed: Males: 5,2 ± 1,7 cm ; Females: 4,9 ± 1,1 cmCoP max speed: Males: 5,0 ± 1,2 cm ; Females: 5,5 ± 0,1 cm• Functional Reach and CoP displacements of females are inferior

to those of males (except CoP at max speed), but the differences are smaller than those of young subjects; no sense looking for significance, particullarly about females

About gender influence

Relationship Fr - CoP

• Both for young and elder subjects CoP increases with FR but correlation coefficients are very small (mean 0,5).

• No significative differences between young and elder population

About Functional Reach

• The comparison shows a significant decrease of FR and CoP with age

• The behaviour during the test does not depend on gender

• Functional reach is a real clinical test to compare different age subjects

• Functional Reach measure may identify damages that cause balance instability

• Functional Reach test can be extended to not completely self-sufficient subjects (ictus, Parkinson, Alzheimer, orthopedic traumas)

Applications

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