Biomedical Engineering Reference
In-Depth Information
Chapter Seven
Functional Electrical Stimulation Leg
Exercise: From Technology to Therapy
Nur Azah Hamzaid
∗
,†
, Che Fornusek
∗
and Glen M Davis
∗
∗
Clinical Exercise and Rehabilitation Unit, University of Sydney, Lidcombe,
NSW 2141, Australia
†
Department of Biomedical Engineering, Faculty of Engineering, University Malaya,
50602, Kuala Lumpur, Malaysia
7.1 INTRODUCTION
Functional electrical stimulation (FES) is the application of external electrical
currents to elicit muscle contractions using a neuromuscular stimulator, thereby
bypassing the central nervous system (Holsheimer 1998). Muscle contractions via
transcutaneous FES employs a control switch, a stimulator and a pair of electrodes
deployed over the muscle belly (Sisto, 2009). When electrical stimulation is applied
these muscles contract to produce motion, force and power.
Electrically stimulated contractions are employed to achieve 'functional' out-
comes such as walking, standing or cycling, and to reverse foot-drop during gait in
hemiplegic patients (Currier, 1992). In spinal cord injury (SCI) rehabilitation, FES
is used to maintain or increase range of motion, ablate contractures, strengthen
muscles, facilitate voluntary motor function, reduce spasticity, and prevent circu-
latory or orthostatic hypotension. In addition, FES is extensively used as a way
of making possible exercise using the paralysed limbs (Sisto, 2009). Although
not strictly “functional”, FES-induced leg cycling has known benefits (Davis,
2008; Hamzaid, 2009) and it is broadly included because such benefits enhance
functional outcomes.
7.2 EXERCISE FOR PEOPLE WITH NEUROLOGICAL DISABILITIES
Regular physical activity is beneficial not only for the able-bodied population, but
also for people with neurological disabilities (Myslinski, 2005). Regular exercise
