Operation Manual

MyotonPRO User Manual
Page 102 of 108
Appendixes
Appendix 1 – Definitions of parameters
STATE OF TENSION
F – Oscillation Frequency [Hz]
indicates the Tone (that is, intrinsic tension) of a muscle in its passive or resting state without
any voluntary contraction (EMG base level). Hypertonia and respectively increased intramuscular
pressure causes reduced blood supply, which brings on worse muscle recovery and quicker muscle
fatigue. Oscillation Frequency in contracted state indicates the tension of a muscle.
BIOMECHANICAL PROPERTIES
S – Dynamic Stiffness [N/m]
Stiffness is the biomechanical property of a muscle that characterises the resistance to a
contraction or to an external force that deforms its initial shape.
Greater effort is required from the agonist muscle to extend the antagonist muscle with high
stiffness, which leads to inefficient economy of movement. The term Dynamic Stiffness originates
from the dynamic measurement method applied in MyotonPRO.
The inverse of Stiffness is Compliance.
D – Logarithmic Decrement
of a muscle’s natural oscillation indicates the muscle’s elasticity. Elasticity is the biomechanical
property of a muscle that characterises the ability to recover its initial shape after a contraction
or removal of an external force. Elasticity is inversely proportional to the decrement. In theory a
decrement of 0 (zero) represents absolute elasticity (that there is no dampening of the muscle’s
oscillation: on the Figure 5 a
1
= a
3
).
Natural log from a1 / a3 describes the dampening ratio due to the dissipation of mechanical
energy in the tissue during one oscillation cycle. If the muscle dissipates less mechanical energy
then it is more elastic. If the muscle is more elastic then it is more economic and efficient in
function.
The inverse of Elasticity is Plasticity.