IRT is the acronym  term used to describe such techniques and Instability Resistance Training is reviewed with references in a 2012 article and is freely available to all via Pubmed Central as full text.   PMC3325639

THE EFFECTIVENESS OF RESISTANCE TRAINING USING UNSTABLE SURFACES AND DEVICES FOR REHABILITATION

David Behm, PhD1 and Juan Carlos Colado, PhD2 from Canada and Spain.

more recent articles that cite this article and should provide you with helpful details are also available in  PMC.

 Abstract

Background and Purpose:

While the popularity of instability resistance training (resistance training that involves the use of unstable surfaces and devices: IRT) is evident in fitness training facilities, its effectiveness for optimal sport performance training has been questioned. The purpose of this clinical commentary is to explore the resistance training literature, which implements the use of unstable surfaces and devices to determine the suitability of IRT for rehabilitation.

Description of Topic and Related Evidence:

The criticism of IRT for athletic conditioning is based on the findings of impaired kinetic measures such as force, power and movement velocity during a bout of IRT compared to traditional resistance training with more stable surfaces or devices. However, these deficits occur concurrently with minimal changes or in some cases increases in trunk and limb muscle activation. Compared to the kinetic deficits that are reported during unstable resistance exercises, the relatively greater trunk muscle activation indicates a greater stabilizing function for the muscles. IRT exercises can also provide training adaptations for coordination and other motor control issues, which may be more important for low back pain rehabilitation than strength or power enhancements.

Relation to Clinical Practice:

Improvements in postural stability from balance training without resistance can improve force output which can then lead to a training progression involving an amalgamation of balance and IRT leading to higher load traditional resistance training.

Hope this helps you !

Best

You can try the articles about the FlexChair by VelDon.

Dear Alan,

Thank you for the suggestion. I read the article suggested by you. It has given me ideas to explain my hypothesis of my study with stroke patients and swiss ball. I will post my understanding of the main article and the cross references later.