The main finding of the present study was that a high intensity shoulder elevation contraction did not modify RPE, productivity or EMG activity of the upper trapezius during the subsequent pause and computer work.
Interventions: Subjects completed 3 maximal isometric shoulder elevation contractions at 90° of sagittal plane elevation in the SN, SP, and SR positions.
Active MTrPs, which are painful spots that produce familiar shoulder pain during contraction, stretching or compressing, these MTrPs may provide an alternative explanation for shoulder pain, which is independent of the presence of subacromial abnormalities.
Recent publications suggest limitations for surgical indications in cases with co-contractions (which may present as an inability to flex the elbow and abduct and externally rotate the shoulder although some contractions in the affected muscles may also be observed).
The purpose of the study is to examine the effects of push-up plus variants and elbow position on vertical ground reaction force and electromyographical activity of four shoulder muscles during concentric contraction.
18 female computer workers performed 2 sessions of 15 min standardized computer mouse work preceded by 1 min pause with and without prior high intensity contraction of shoulder elevation.
It is our opinion that in our Group I patients, the co-contraction between shoulder abductors (supraspinatus, infraspinatus and deltoid) and adductors (mainly, pectoralis major, teres major and latissimus dorsi) and also subscapularis muscle tightness cause limitation of shoulder elevation.
This involved both push strength (maximal voluntary isometric contraction of the shoulder flexors/adductors) and pull strength (maximum voluntary isometric contraction of the shoulder extensors/abductors). Results were recorded to the nearest 0.5 kg.
That study examined both isometric and dynamic (eccentric and concentric) muscle contractions, and found that acute shoulder pain impaired force variability during isometric contractions only, and not during dynamic contractions [ 17].
There was no contraction of the shoulder girdle muscles.
