a heel drop-raise exercise Taija Finni Neuromuscular Research - - PowerPoint PPT Presentation

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Sep 04, 2022 319 likes •541 views

Muscle-tendon mechanics of a heel drop-raise exercise Taija Finni Neuromuscular Research Center Department of Biology of Physical Activity University of Jyvskyl Taija Finni 22.9.2016 Biomechanics symposium, Jyvskyl Stretch-Shortening

SLIDE 1

Muscle-tendon mechanics of a heel drop-raise exercise

Taija Finni Neuromuscular Research Center Department of Biology of Physical Activity University of Jyväskylä

Taija Finni 22.9.2016 Biomechanics symposium, Jyväskylä

SLIDE 2

Stretch-Shortening Cycle

Braking phase Push-off phase

Muscle-tendon unit Lengthens Shortens Muscle fibers

? ?

Taija Finni 2001, PhD defense

Taija Finni 22.9.2016 Biomechanics symposium, Jyväskylä

SLIDE 3

When does eccentric muscle action occur?

What was this locomotion?

Fascicle length change (mm)

Cronin & Finni 2013

RUNNING HOPPING WALKING

Hoffren et al. 2012

Taija Finni 22.9.2016 Biomechanics symposium, Jyväskylä

SLIDE 4

Heel drop-raise exercise

Calf-raise test -> clinical test
Heel raise exercise
Heel drop-raise exercise

Alfredson et al. 1998

Eccentric component?

Taija Finni 22.9.2016 Biomechanics symposium, Jyväskylä

SLIDE 5

Muscle-tendon function in heel drop-raise exercise

Taija Finni, Emma Niemi, Andrew G Cresswell & Glen A Lichtwark

Taija Finni 22.9.2016 Biomechanics symposium, Jyväskylä

SLIDE 6

Muscle-tendon function in heel drop-raise exercise

Taija Finni, Emma Niemi, Andrew G Cresswell & Glen A Lichtwark

How is tendon and aponeurosis length (and stiffness) modulated with increasing force and in different types

f muscle actions?

Hypotheses:

With higher load the tendon elongates more but the

aponeurosis does not.

Force Length

Tendon

Taija Finni 22.9.2016 Biomechanics symposium, Jyväskylä

SLIDE 7

Tendon-aponeurosis strain%

MVC % Achilles tendon strain Aponeurosis strain Reference & muscle

2 4

Arampatzis et al. 2006 GM - elongated

20 2.8 <1.2

nonuniform Finni et al. 2003 SOL

40 4.7 <2.2

nonuniform Finni et al. 2003 SOL

100 8.0 1.4

Magnusson et al. 2003 GM

Free Achilles tendon Aponeurosis

f insertion

Relevance: Use of elastic potential in tendon,

ptimize muscle performance

Force Length

Tendon

Taija Finni 22.9.2016 Biomechanics symposium, Jyväskylä

SLIDE 8

Tendon vs. aponeurosis

Tilp et al. 2012

Aponeurosis length changes do not depend on force alone but depend critically on activation level...

Tibialis anterior muscle At given TA force, length of elastic tissues dependes on muscle length: longer length, smaller length chang Raiteri et al. 2016 ASBabstract Taija Finni 22.9.2016 Biomechanics symposium, Jyväskylä

SLIDE 9

Muscle-tendon function in heel drop-raise exercise

Taija Finni, Emma Niemi, Andrew G Cresswell & Glen A Lichtwark

How is tendon and aponeurosis length (and stiffness) modulated with increasing force and in different types

f muscle actions?

Hypotheses:

With higher load the tendon elongates more but the

aponeurosis does not.

Aponeurosis stiffness is different between contraction

modes at a given force level

Tilp et al 2012: TA aponeurosis lengthens less in

eccentric vs. concentric action.

Muscle fascicle function?

Taija Finni 22.9.2016 Biomechanics symposium, Jyväskylä

SLIDE 10

Methods

Bilateral & Unilateral
30 & 50 times/minute
With body weight up to +40%BW

Taija Finni 22.9.2016 Biomechanics symposium, Jyväskylä

SLIDE 11

Movement symmetry

0,2 0,4 0,6 0,8 1 1,2

30/min 50/min Time (s)

CON ECC

Time of the phases

Achilles tendon force (kN)

CON mean ECC mean

BL BL+30 BL+40 UL UL+10 UL+30 0.5 1.0 1.5 2.5 3.0 2.0

Mean tendon forces of the phases Taija Finni 22.9.2016 Biomechanics symposium, Jyväskylä

SLIDE 12

Methods

Bilateral & Unilateral
30 & 50 times/minute
With body weight up to +40%BW

MG fascicle Muscle- tendon junction

Motion capture
Ground reaction forces
Ultrasonography

Taija Finni 22.9.2016 Biomechanics symposium, Jyväskylä

SLIDE 13

Heel raise-drop cycle

Taija Finni 22.9.2016 Biomechanics symposium, Jyväskylä

SLIDE 14

Methods

Ultrasound in lab space MG fascicle MG tendon Aponeurosis

Joint moments -> Achilles tendon force
Joint angles -> MG muscle-tendon unit length

Taija Finni 22.9.2016 Biomechanics symposium, Jyväskylä

SLIDE 15

Achilles tendon force

Moment arm ratios change Taija Finni 22.9.2016 Biomechanics symposium, Jyväskylä

SLIDE 16

1000 400 600 800 ATF (N) EMG (%) 4.5 4.4 ATma (cm) 0.4 0.6 0.2

MTU min MTU max

ECC CON

AT moment arm in walking

(Rasske et al. 2016)

Taija Finni 22.9.2016 Biomechanics symposium, Jyväskylä

SLIDE 17

Activation level

Mean Achilles tendon force (N) Normalized EMG (%MVC) Taija Finni 22.9.2016 Biomechanics symposium, Jyväskylä

SLIDE 18

Achilles tendon force

Do fluctuations provide stimulus for tendon? Vibration stimulates collagen synthesis Taija Finni 22.9.2016 Biomechanics symposium, Jyväskylä

SLIDE 19

Do muscle fascicles stretch?

Fascicle length change (mm)

Cronin & Finni 2013

RUNNING WALKING Taija Finni 22.9.2016 Biomechanics symposium, Jyväskylä

SLIDE 20

Do muscle fascicles stretch in heel drop exercise?

Concentric Eccentric Taija Finni 22.9.2016 Biomechanics symposium, Jyväskylä

SLIDE 21

Take home messages

Stretch of muscle fibers is uncoupled from MTU

– Muscle specificity – Movement specificity

Tendon – aponeurosis behavior is

uncoupled

Tendon oscillates in eccentric phase of

heel drop

– > stimulus for collagen synthesis?

Taija Finni 22.9.2016 Biomechanics symposium, Jyväskylä