The use of surface electrodes to record infraspinatus activity is not valid at low infraspinatus activation levels

Alterations in central motor representation increase over time in individuals with rotator cuff tendinopathy

“…3-4 cm below and running parallel to the spine of the scapula, over the infraspinatus fossa (Delagi and Perotto, 1980). This arrangement has shown high levels of agreement between surface and intramuscular recordings (Johnson et al, 2011). EMG signals were amplified (1000x), bandpass filtered (20-1000 Hz), digitized at a sampling rate of 2000 Hz (Power1401 interface; Cambridge Electronic Design, Cambridge, United Kingdom) and stored on a computer for off-line analysis.…”

A comparison of surface and fine wire EMG recordings of gluteus medius during selected maximum isometric voluntary contractions of the hip

“…maximum voluntary contractions) provide a unique opportunity for comparing activity from surface and fine wire recordings. Previous studies on other muscles suggest that the electrode recordings are comparable when the muscle is contracting at a moderate to high intensity (>60% maximum voluntary isometric contraction, MVIC) (Johnson et al, 2011). However, when a muscle is contracting at a low intensity (<10% MVIC) under high load (e.g.…”

“…Despite these benefits, there are some disadvantages that would potentially result in the recording of invalid or misleading data. In the context of GMed EMG research, these disadvantages are primarily related to the inability of surface electrodes to detect activity from deeply situated muscles; and the vulnerability of surface electrodes to record additional myoelectric activity (cross-talk) from surrounding muscles or muscle segments (Chapman et al, 2006(Chapman et al, , 2010Johnson et al, 2011;Waite et al, 2010).…”

“…However, when a muscle is contracting at a low intensity (<10% MVIC) under high load (e.g. in a task where the target muscle is not considered a prime mover), surface electrodes are vulnerable to recording additional myoelectric activity from surrounding muscles when compared with fine wire electrodes (Chapman et al, 2010;Johnson et al, 2011). The aim of the current study was therefore to compare surface and fine wire recordings of GMed at high and low intensities of muscle contractions, under high load conditions (MVICs).…”

Shoulder muscle activity during the modified dynamic relocation test and side-lying shoulder external rotation: a cross-sectional study on asymptomatic individuals

“…While surface electrodes provide a painless and non-invasive method for recording muscle activity, their spatial resolution is somewhat limited. 33,34 An alternative for surface electrodes is the use of indwelling electrodes, which have far smaller receptive fields but may be limited in their ability to accurately represent whole-muscle activation levels. [34][35][36] Despite its spatial limitation, SEMG has been commonly used for recording rotator cuff muscle activity.…”