# Shoulder weakness induces trunk compensation after a stroke

Germain Faity, Denis Mottet, Karima Bakhti, Jérôme Froger, Isabelle Laffont

► To cite this version:

Germain Faity, Denis Mottet, Karima Bakhti, Jérôme Froger, Isabelle Laffont. Shoulder weakness induces trunk compensation after a stroke. 16th world congress of the ISPRM, Jul 2022, Lisboa, Portugal. . hal-03778164

HAL Id: hal-03778164

https://hal.science/hal-03778164

Submitted on 15 Sep 2022

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## INTRO

* Most stroke patients do not use their paretic limb even when they are able to do so, often resulting in secondary loss of function.

* Healthy people adapt their elbow-shoulder-trunk coordination to minimize the torque at the shoulder.

* The aim of this study is to evaluate how shoulder weakness after stroke impacts elbow-shoulder-trunk coordination.

## METHODS

* 17 out of 22 patients recruited

* Supratentorial stroke (> 1 month)

* EMG + Motion Capture (Kinect v2)

* Reaching: Spontaneous VS Self-limited trunk

# After a **stroke**, shoulder **weakness** leads to **changes** in arm-trunk coordination.

<figure><img src="image_2.png" /><figcaption>**Healthy participant**
Without arm lightening</figcaption></figure>

<figure><img src="image_3.png" /><figcaption>**Stroke participant**
Without arm lightening</figcaption></figure>

<figure><img src="image_4.png" /><figcaption>**Stroke participant**
With arm lightening</figcaption></figure>

After a stroke, shoulder strength is reduced by half

Trunk compensations allow a more normal neuromuscular activity and perceived exhaustion

Lightening the arm reduces compensation

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<figure><img src="image_7.png" /></figure>

<figure><img src="image_8.png" /></figure>

## DISCUSSION

* The observed compensation is not merely a 'poor coordination', but more likely a 'good adaptation' to the weakness of the shoulder after the stroke.

* Given the beneficial effect of the antigravity device, future work may evaluate the effect of **strength training** on reducing compensations.

Ongoing study

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EuroMov
Digital Health in Motion

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IMT Mines Alès
École Mines-Télécom

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Faity G., Mottet D., Bakhti K., Laffont I., Froger J.

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germain.faity@umontpellier.fr

CHU

MONTPELLIER

CENTRE
HOSPITALIER

UNIVERSITAIRE