Monday, April 6, 2009
Pain is Bad for Performance: New Study on Shoulder Pain
I am sure everyone is tired of hearing me yack about how bad pain is for performance and proper muscle coordination. If you have missed my tyrants in the past, see the following by clicking on them
In this study, they created pain in healthy people and then saw that it decreased shoulder muscle activity. The researchers stated,
"During abduction, experimentally induced pain in the supraspinatus muscle caused a significant decrease in activity of the anterior deltoid, upper trapezius and the infraspinatus and an increase in activity of lower trapezius and latissimus dorsi muscles."
The body is showing an arthrokinetic reflex where it is working to protect the joint by starting to shut down the muscles around it. Makes sense since your body is survival based, not performance based. You can get an increase in performance by increasing the ability of it to survive. This is a basic concept taught in Z Health R Phase.
Mobility drills (like Z Health) can be used to correct the joints and thus muscular function.
For maximal performance, get out of pain. A vast majority of the time, better movement = less pain.
Below is the full study
Louise Pyndt Diederichsen1, 4, 5 Contact Information, Annika Winther1, Poul Dyhre-Poulsen2, Michael R. Krogsgaard3 and Jesper Nørregaard1
(1) Institute of Sports Medicine-Copenhagen, Bispebjerg Hospital, Copenhagen, Denmark
(2) Department for Medical Physiology, Panum Institute, University of Copenhagen, Copenhagen, Denmark
(3) Department of Orthopaedic Surgery M, Bispebjerg Hospital, Copenhagen, Denmark
(4) Division of Rheumatology, Department of Medicine, Odense Universitetshospital, Sdr. Boulevard 29, 5000 Odense C, Denmark
(5) Lodsvej 25A, 5270 Odense N, Denmark
Muscle function is altered in painful shoulder conditions. However, the influence of shoulder pain on muscle coordination of the shoulder has not been fully clarified. The aim of the present study was to examine the effect of experimentally induced shoulder pain on shoulder muscle function.
Eleven healthy men (range 22–27 years), with no history of shoulder or cervical problems, were included in the study. Pain was induced by 5% hypertonic saline injections into the supraspinatus muscle or subacromially. Seated in a shoulder machine, subjects performed standardized concentric abduction (0°–105°) at a speed of approximately 120°/s, controlled by a metronome.
During abduction, electromyographic (EMG) activity was recorded by intramuscular wire electrodes inserted in two deeply located shoulder muscles and by surface-electrodes over six superficially located shoulder muscles.
EMG was recorded before pain, during pain and after pain had subsided and pain intensity was continuously scored on a visual analog scale (VAS). During abduction, experimentally induced pain in the supraspinatus muscle caused a significant decrease in activity of the anterior deltoid, upper trapezius and the infraspinatus and an increase in activity of lower trapezius and latissimus dorsi muscles. Following subacromial injection a significantly increased muscle activity was seen in the lower trapezius, the serratus anterior and the latissimus dorsi muscles.
In conclusion, this study shows that acute pain both subacromially and in the supraspinatus muscle modulates coordination of the shoulder muscles during voluntary movements. During painful conditions, an increased activity was detected in the antagonist (latissimus), which support the idea that localized pain affects muscle activation in a way that protects the painful structure.
Further, the changes in muscle activity following subacromial pain induction tend to expand the subacromial space and thereby decrease the load on the painful structures.