How Does the IOPI Measure Strength?
IOPI measures the maximum pressure (Pmax) is applied to an air-filled bulb when it is compressed between the tongue or lip and a hard surface, e.g. the palate or teeth respectively). Pmax is therefore a measure of strength, shown in kilopascals (kPa) which is an international unit of pressure.
How Does the IOPI Measure Endurance?
Clinicians working with patients with dysphagia or dysarthria will recognise the importance of measuring oro-motor fatiguability. IOPI measures endurance, which is inversely proportional to fatiguability, therefore a patient demonstrating low endurance values has a high level of fatiguability.
IOPI Pro measures endurance by quantifying the length of time (in seconds) that a patient can maintain 50% of their Pmax. This procedure is performed in Target Mode. The clinician sets the target value to 50% of the patient’s Pmax & then times how long the patient can maintain this value, shown as a green light in the biofeedback light array.
How is IOPI used for Exercise Therapy?
The clinician will compare the strength and endurance data against the normal values provided by IOPI Medical to assist in identification of patients that would be suitable for a therapy program. The clinician will determine what target value is appropriate for exercise therapy and provides specific instructions to the patient for a particular exercise protocol. A typical exercise protocol would include the following parameters:
- Intensity (based on 2 factors: the maximum pressure (Pmax) and the effort level (typically 60 – 80% of their Pmax). Adjustments should be made as therapy progresses.
- Frequency (incorporating: repetitions per set, sets per session, sessions per day, days per week and number of weeks).
Progressive isometric resistance programs are commonly used to increase strength, and have been successfully applied to the tongue (see Burkhead, L. M., Sapienza, C. M, and Rosenbek, J. C. (2007). Strength-Training Exercise in Dysphagia Rehabilitation: Principles, Procedures, and Directions for Future Research. Dysphagia, 22(3), 251-265). The protocol’s intensity should be reassessed and adjusted over time as the patient’s Pmax increases and the effort level increased as therapy progresses. The protocol frequency for a progressive resistance exercise program typically involves 2 – 3 sets per day, 3 – 5 days per week and over 6 – 12 weeks.
In addition to strength development, the IOPI® Pro can provide biofeedback for tasks related to neuromuscular coordination such as controlled timing tasks or awareness training. Yeats et al. have suggested that the training of controlled movements of the tongue in the patients with dysphagia they studied significantly contributed to improvements in these patients (see Yeates E. M., Molfenter S. M., and Steele C. M. (2008). Improvements in tongue strength and pressure-generation precision following a tongue-pressure training protocol in older individuals with dysphagia: Three case reports. Clinic. Intervent. in Aging, 3:735-747).; IOPI® has been validated in many scientific studies, please see the attached references for additional information.
