Mbody Case study

Case study based on the research by R. Kalema

NEUROMUSCULAR CHARACTERISTICS OF QUADRICEPSAND HAMSTRINGS MUSCLE DURING A SOCCER MATCH

KNOW YOU - KNOW YOUR MUSCLES

CASE BACKGROUND

Rudy Kalema is a physical trainer and a sport science adviser with almost

10 years experience in elite football. During his career he had worked with

Royal Sporting Club Anderlecht (Belgium), Helsingin Jalkapalloklubi

(Fnland), AL-Shabab FC (Saudi Arabia) and Koninklijke Sint-Truidense

Voetbalvereninging (Belgium).

Kalema was introduced with Mbody during his studies at the University of

Jyväskylä where smart shorts were used in several projects. Later, while

working as a professional sport scientist in STVV Mbody was used by

Kalema in collaboration with the team’s physiotherapys as a screening

device to monitor muscle activity in order to prevent injuries and optimize

rehabilitation processes.

In 2012 Kalema has published a study, “Neuromuscular characteristics

of quadriceps and hamstring muscle during a soccer match”, on

implementing Mbody muscle monitor system into soccer. The purpose of

the study was to investigate the influence of fatigue on athletes

performance during an actual soccer match through and EMG activity of

the right and left quadriceps and hamstrings.

“Injuries often occur in training or matches. During the match you have the

actual load and movement pattern of the soccer players. I thought that

using Mbody in the actual game would open a new dimension and

provide us with the insight data. It could give us answers to the questions

like: What is happening with muscle during the match? How muscles are

behaving at the end of the match? Where majority of observed injuries

occur?”, says Kalema.

THE ROLE OF THE MUSCLE CONTROL IN SOCCER

Soccer is the world’s biggest team sport with an estimate of 230 million

players. It is a complex contact sport with high technical and tactical and

physiological demands. In soccer injuries are a recognized problem.

Studies on soccer injuries risk suggest that 65% - 95% of the players

have an injury during the season (Ekstrand et al. 2005).

In female soccer most common injury is a knee injury, also known as

ACL-tear. Quadriceps and hamstrings are functionally important to

control stability of the knee joint complex. Studies on ACL injury

mechanisms have suggested that the hamstring muscle has a crucial role

in protecting the ACL during the movements (Gehring et al. 2009). It

has ben suggested that fatigue is an important factor that may influence

stabilizing control and thus cause ACL injuries, especially between the

75th and 90th minutes of the game (Hawkins et al. 1999).

Concerning male football, it appears that thigh muscle strain injuries are

among the most common and account for 10% to 23% of all acute

injuries. The injury with the most prevalence is the hamstring strain,

which account for 12-16% of total injuries(Caine et al. 2010, 214- 215).

230 MILJSOCCER PLAYERS WORLDWIDE

INJURY RATE IN SOCCER PER 1,000

ATHLETE

7,3WOMEN

7,6MEN

65.3% AFFECT

LOWER LIMB

65.6% AFFECT

LOWER LIMB

SOURCE: NCAA SPORTS INJURY FACT SHEETS. NCAA SPORT INJURY

FACT SHEETS ARE PRODUCED BY THE DATALYS CENTER FOR SPORTS

INJURY RESEARCH AND PREVENTION IN COLLABORATION WITH THE

NATIONAL COLLEGIATE ATHLETIC ASSOCIATION, AND STOP SPORTS

INJURIES. THE DATALYS CENTER MANAGES THE NCAA INJURY

SURVEILLANCE PROGRAM.

Fatigue represents a reduction in the ability of muscle to generate force and

in the context of football, it has been often related with injury. Surface

electromyography is a valuable technique for evaluating muscle activation

and fatigue which has never previously been applied to monitor muscle

activation during a real football match. The development of washable textile

electrodes has opened up possibilities to investigate muscular activity in non-

laboratory settings, without skin preparation and wires hanging around the

body. It has also been shown to be a valid and feasible method for assessing

the average rectified value of electromyography (EMG).

The purpose of this study was to measure EMG activity during an actual

soccer match in order to find out how the workload induced by this physically

demanding sport will affect the activity of two important lower limb’s group of

muscle, quadriceps and hamstrings. Muscle activity and inactivity

were compared between the first 15 minutes of the 1st half (PRE) and last 15 minutes of the 2nd half (POST).

Eight professional players, from the Finnish soccer league, volunteered

for these study. All of the subjects were selected if not injured or

recovering from injury at the time of assessments. Players professional

experience in soccer was between 5-8 years and training volume was

4-6 sessions plus 1-2 matches per week. Study protocol was conducted

in both laboratory and the field conditions. On the first day the subject

performed an isometric maximal voluntary contraction in knee

extension machine, followed by a 3 stage treadmill running test while

wearing Mbody shorts. On the other day measurements of muscle

activity was performed during three unofficial soccer matches.

NEUROMUSCULAR CHARACTERISTICS OF QUADRICEPS AND

HAMSTRING MUSCLE DURING A SOCEER MATCH

90

80

70

60

50

40

30

20

10

0*

LH RH LQ RQ LH RH LQ RQ LH RH LQ RQ LH RH LQ RQ

Inactivaty Light Moderate Vigorous

Mus

cle

activ

ity (

% o

f rec

ordi

ng ti

me)

PRE

POST

*

**

* **

10

5

0

LH RH LQ RQ

Comparison EMG activity of LQ, LH, RQ and RH during the first (PRE) and last 15 minutes (POST) of the match. (*p< .05) Kalema 2012).

25

20

15

35

30

Ave

rage

EM

G (

% E

MG

MV

C)

PRE

POST

**

PRE and POST muscle activity profile of LQ , LH, RQ and RH. Inactivity time (threshold set as > 2% EMGMVC , light activity time (> aEMG at 6km/h), moderate activitytime (> aEMG at 12 km/h) and vigorous activity time (> aEMG at 16 km/h) (*p< .05) (Kalema 2012).

RESULTS

CONCLUSIONS AND FURTHER ACTIONSInside Feedback from

the movement and

Quality of the movement

Athletes learning& Self monitoring

Real time Analysis, Long distance Control and Fast

feedback for athlete &coach/physio

ADVANTAGES

OF MUSCLE

MONITORING

✓ During this study muscle activity of lower limbs was measured in the real

soccer match conidtions for the first time. As the resultes have show'n EMG

activity has a tendency to decrease during fatigue at the end of the game. The

results show that players spent more time at the lowest EMG intensity and that

while inactivity time increases in the last 15 minutes vigorous activity time

decreases. (Kalema 2012)

✓ These fluctuations in the neuromuscular activity will probably have an impact

on force generation of the muscles and indirectly cause injuries.The present

finding represents an important step in injury prevention, rehabilitation and

conditioning field. With the help of Mbody it is now possible to monitor the

individual changes in the neuromuscular activity of two important muscles, in

fatigue conditions to and see what is the actual time spent on the field before

the maximum muscle load is reached and player becomes more exposed to the

potential high risk injury. (Kalema 2012)

✓ Results give a promising starting point for using EMG in studying performance

and preventing injuries during intensive sport activities such as football (Kalema

2012).

THE MBODY TEAM

“

The Mbody solution incorporates intelligent clothing with wireless

connectivity and mobile interfaces. This short - packed with wearable technology

such as built-in textile sensors - measures activity of your muscle groups,

Quadriceps and Hamstrings on both legs. The data can be followed on your mobile

phone or pad, both during and after your exercise.

“

”

There is an international and versatile team of

professionals who have gained success in Olympic level sports, and in the field of software

engineering, university and research.

”

REFERENCES

Kalema, R., 2012. Department of Biology of Physical, University of Jyvaskyla. Master’s Thesis in Exercise Physiology: Quadriceps and hamstring muscle

EMG activity during a football match. https://jyx.jyu.fi/dspace/bitstream/handle/123456789/41027/URN%3aNBN%3afi%3ajyu-201303071300.pdf?sequence=1

NCAA, Men’s soccer injuries, Data from the 2004/05-2008/09 Seasons https://www.ncaa.org/sites/default/files/NCAA_M_Soccer_Injuries_WEB.pdf

NCAA, Women’s soccer injuries, Data from the 2004/05-2008/09 Seasons

http://www.datalyscenter.org/f73d016ffb_sites/datalyscenter.org/files/NCAA_W_Soccer_Injuries_HiRes.pdf

Ekstrand, J., Hägglund, M. & Walden, M. 2005. UEFA Champions League Study: A prospective Study of Injury in Professional Football during the 2001-2002 Season.

British Journal of Sports Medicine 39(8), 542-546.

Gehring, D., Melnyk, M. & Gollhofer, A. 2009. Gender and fatigue have influence on the knee joint control strategies during landing. Journal of

Clinical Biomechanics 24(1), 82-87. Hawkins, R. & Fuller, C. 1999. A prospective epidemiological study of injuries in four English professional

football clubs. British Journal of Sports Medicine 33(3), 196- 203.

Caine D. J., Harmer P. A. & Schiff, M. A. 2010. Epidemiology of injury in olympic sports. Wiley-Blackwell.

Smart Data for Health & Performance

PULS@CARE –EArise Software & Management

Jean CHAILLET, COO Asia+66 97 075 5150

j.chaillet@pulsacare.com

CONTACTS