How it works.
The GS Analyser is a highly accurate, objective measurement and recording system for neuromusculoskeletal assessment and rehabilitation. The GS Analyser is designed to measure the isometric voluntary muscle contractions of the body’s muscle groups. This can be done maximally to measure a peak force, sub maximally to measure a fatigue rating, or against a template to perform rehabilitation.
It is vital to isolate the muscle group being assessed, minimising recruitment, and ensuring that the GS Gatherer is measuring the isometric force; to do this, the GS Analyser utilises a range of positions for the client.
Back to the basics
Issac Newton's third law states that for every action (force) there is an equal and opposite reaction. In other words, if object A exerts a force on object B, then object B also exerts an equal force on object A. This is the fundamental principle behind the GS Analyser.
Lets apply this law to the GS Analyser. Watch the video on the right. The user (in white) is object A. Through the GS Analyser and Harness, object A is applying a force to the client's neck. The client is object B. Object B exerts an equal and opposite force to that applied by object A. The force exerted by the client (B) is recorded using the GS Analyser. When the force applied by the user (A) becomes too great for client (B) to overcome, you have demonstrated the maximum force the user can produce at that position.
Neuromusculoskeletal - What on earth?
A long and complicated word which you will have no doubt seen written a few times on this website. But what does it mean? The terms attempts to encapsulates the idea the your bones, muscles and nerves all work together as one unit. You may have heard the term musculoskeletal. Simply, "Musculo" - muscles and "Skeletal" - skeleton/bones. Therefore a term referring the muscles attached to your bones. "Neuro" refers to the nerves which then control the muscles, which then move the bones. The GS Analyser is an assessment tool of not just your muscles and bones (musculoskeletal), but also of the nerves which move the muscles - hence neuromusculoskeletal analysis.
The GS Analyser measures isometric voluntary muscle contraction or "one-rep max". Unlike large fixed devices, the GS Analyser can measure anywhere from the neck, all the way to the foot. The gallery below demonstrates the various testing positions used by the GS Analyser. The Analyser, along with the GS Harness and various body applicators fit conveniently in a simple backpack. We test isometric strength. Why? You obtain the most accurate representation of your one-rep max, as opposed to eccentric isokinetic testing which can give you up to 120% of one-rep max or concentric isokinetic testing which will only give you up to 90%. Bio-mechanically safe, we test most joints in the 90 degree position which offers optimum actin-myosin cross-bridging for maximum muscle output. For more information, watch Part 3 of the GS Analysis Suite tutorial.
A feature unique to the GS Analysis is its ability to obtain accurate and reproducible data on muscle fatigue rates. Once the peak isometric muscle contraction (one-rep max) for the particular muscle/muscle group is determined, the user will typically be tested on the duration of how long half the peak isometric muscle contraction can be maintained. Therefore fatigue is measured as a function of time. For example, is an individual generated 30 kg for peak isometric muscle contraction, the fatigue rate would be determined by how long the individual have hold 15 kg of force. Below is an image taken from the GS Analysis Suite showing a cervical extension fatigue assessment. On the right is a client undergoing a fatigue assessment. Along the X-axis is time, with force on the Y-axis. A trace will appear and the user must follow the black line which represents the target force (usually half one-rep max). The test will end own the user can no longer maintain the target force.
The GS Analysis Suite has unique training templates that are derived from the test results. This means each rehabilitative intervention is fact based and does not rely on “expert opinion” or guess work. This assures safe and appropriate fast rehabilitation to the physical therapy profession and assurances to the surgical and medical specialists. Collation of this data will lead to defining clinical outcomes and best practice recommendations for diagnosis, management and return to full health. The image below shows a typical rehabilitation template for shoulder adduction. Similar assessment fatigue, the user must match the trace with the black line given.
The Technical Stuff
The GS Analyser comprises of a bi-directional load cell, a device that can measure load (force) in two directions (compression and tensile forces).
The load cell itself is a highly specialised piezoelectric sensor, a device that uses the piezoelectric effect to measure force. Changes in force are converted into an electrical charge which is then transmitted via radio-frequency to the paired computer and displayed on the GS Analysis Suite.