Isokinetic movement has been available since the 1950’s. In contrast to other forms of motion isokinetic movement permits maximum muscle contraction throughout the full range of motion, rather than just perpendicular to the line of force. The concept was not an immediate success as machines were prohibitively expensive and few were available outside of research laboratories.
Lumex, Inc, a therapeutic and hospital product company, purchased the patent for the first isokinetics machine in 1969 from J Perrine and started manufacturing. Because isokinetic resistance gave constant load at preset speed, it had the benefit of not overloading the joint or musculoskeletal unit through a full range of motion, and provided a level of consistent speed of movement that could not be replicated by human resistance. The combination of resistance and speed control became popular, particularly in an age dominated by technology-led rehab.
Major developments occurred in the 1980’s with its connection to first printers and then computers for real time data analysis and interpretation. Shortly thereafter eccentric contractions and continuous passive movement were made available. In the 1990’s adaptions allowed for multiple and multi joint movements and even work simulation tools.
Isokinetic dynamometry is used by physiotherapists in research, education and clinical practice. The preciseness of forces, angles, speeds, etc., provide extraordinary feedback and allow the development of high quality training and rehabilitation. However the high price of a machine still puts it out of the reach of most physiotherapists in clinical practice.
Description provided by Glenn Ruscoe of Australia.
References:
Thomas G. 2020. Isokinetic Dynamometry: So much more than isokinetic. Physical Medicine blog of Biodex. Accessed from https://www.biodex.com/physical-medicine/blog/isokinetic-dynamometry-so-much-more-isokinetics on 15 October 2021.
Wimpenny P. 2016. History of isokinetic(s). Accessed from https://isokinetics.net/index.php/2016-04-05-17-04-58/history-of-isokinetic-s on 15 October 2021.
