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BIOMECHANICAL MEASURMENTS OF PERCUSSIONISTS. Biomechanics …. … combines the principles of mechanics with the fields of biology and physiology: - Kinematics (used to describe motion) - Kinetics (considers forces in motion description). Playing the percussion is a very physical art!.
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BIOMECHANICALMEASURMENTS OF PERCUSSIONISTS
Biomechanics … • … combines the principles of mechanics with the fields of biology and physiology: • - Kinematics (used to describe motion) • - Kinetics (considers forces in motion description)
Playing the percussion is a very physical art! • Musicians are a group of people who perform very specified movements over long periods of time, and can suffer from strain-related injuries (Kaladjev, 2000)… • … thus they require a consciousness of ergonomic issues.
Optimal movement strategy Economical minimise efford avoid fatigue
Why to study players’ movements? • To increase the knowledge about effciency and ergonomics in skilled movements used for artistic purposes. • To describe playing techniques and their effect on the production of sound. • To explore visual communication through movements in music performance.
MEASUREMENTS - Overview • DYNAMICS • DYNAMOMETER • ELECTROMYOGRAPHY (EMG) • FORCE PLATFORM • KINEMATICS • VICON (3D analysis) • reaction time measurement
MEASURMENTS !!! • MUSCULAR STRENGTH- The ability of the muscles to exert force. • RATE OF MUSCULAR FORCE PRODUCTION • MUSCULAR ENDURANCE- The ability to use the voluntary muscles many times without getting tired. • PROPRIOPCEPTION • EMG
Structure of skeletal muscle MUSCLE BELLY TENDON Fibers Connective tissue
Linear motion /translation/ translational movement – a movement along a straight or curved pathway • Angular /rotational motion - motion around some point (it occurs about an imaginary line called the axis of rotation) tram on curved track tram on straight track
Task: You are given a sealed tin of paint and a screw driver, and then you are asked to open it. How will you open the tin? Opening a paint tin with a short screw driver Opening a paint tin with a long screw driver
In human body – only rotational movements occur!!! • The muscles create the moment of force that turn our limbs. The line of action of a muscles force is along its attachements (tendons). The line of action of the muscle force is some distance from the joint axis (d)
Muscle moment arm length • Moment arm = perpendicular distance between the muscle and the point of rotation.
Moment of force Moment is the turning effect of a force M = d * F [Nm] Moment = force (F) × perpendicular distance (d) (moment arm*) * the shortest distance from forces line of action to the axis of rotation
How to assume the moment of muscle force??? • The conditions for static equilibrium allow us to estimate the forces our muscles produce. • If an objects is at rest it is described as being in a state of static equilibrium.
THE MUSCLES OF UPPER LIMB Muscles of shoulder Muscles of hand Muscles of forearm
No appreciable change in length of the muscle (static contraction)
The mean values of max moment of force T – trunk Fl – flexor EX - extensor SH - shoulder El – elbow
The Motor Unit • The smallest functional unit to describe the neural control of the muscular contraction process is called a Motor Unit. • Single motorneuron & muscle fibers it innervates
Rate of muscular force production = Time of contraction vs. force Moment of force [Nm] EMD time [s] Electromechanical delay
Muscles are made up of many muscle fibres. The muscle fibres can be SLOW TWITCH FIBRES or FAST TWITCH FIBRES. We all have both types in our muscles in different quantities, and what we have appears to be handed down from our parents in our genes. SLOW TWITCH FIBRES are deep red in colour and they have a good oxygen supply to the working muscle (runners). These muscles contract slowly but they can work for long periods of time. FAST TWITCH FIBRES are white and work much more quickly, but they also tire more quickly (drummers, swimmers). Percussion playing = high speed motion which uses fast twitch fibers
Muscle Fatigue • Reduction in muscle force production • !!!! Awkward posture or prolonged muscle contraction can lead to muscle fatigue