Fillauer Myolab II, Prosthetist Manual

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11
Proprioceptive neuromuscular
facilitation (PNF) exercise training
has been found effective to develop
remnant musculature in some
amputees. Consult a physical or
occupational therapist, or the Utah
Artificial Arm Users Manual or
Fitting Procedures Manual for more
details.
Figure 7 - Differentiation of two muscle
groups as visualized on Myolab II meters
10. Final Site Selection
Choose the muscle sites only after a reasonable period of training
and practice, so that a potentially good muscle site is not rejected
prematurely. The minimum criteria are:
A. To operate the Utah Artificial Arm, when either muscle “A” or
muscle “B” is contracted the “A” or “B” EMG signal must
exceed the other signal (either “B” or “A”) by:
• 5 microvolts for hand control
• 12 microvolts for elbow control
To measure the EMG signal magnitude accurately, set the gain dial on
10 and the gain switch on X1.
B. The muscle EMG signals should be controllable, without
spasmodic jumping or quivering.
C. Contraction of the muscle should not induce pain.
D. Scar tissue should be avoided, if possible. However, if no
other satisfactory sites are available, electrodes can be used
over scar tissue if designed properly to avoid breakdown of
the scar tissue.
Troubleshooting the Myolab II
1. If you lose the EMG signal to one or both channels, or the signal is
erratic:
• Check the connection to the Myolab II. Be sure the preamplifier
cable (and adapter cable if used) is plugged securely into the
five pin socket in the battery compartment.
• Make sure the power switch is in the on position.
• If you are measuring a very small EMG signal, the signal strength
may be too weak for a gain switch setting of X1. Change to X10.
• Make sure that the gain dial control is at an adequate setting.