COMBI >> Scales >> High Level Mobility Assessment Tool >> Introduction


Gavin Williams, PhD, Epworth Rehabilitation at

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Williams, G. (2006). The High Level Mobility Assessment Tool. The Center for Outcome Measurement in Brain Injury.
combi/himat ( accessed ).





Introduction to the High Level Mobility Assessment Tool

Restricted participation has been well documented following TBI. Existing scales used in neurological rehabilitation are unable to quantify mobility to the level required for participation in physically demanding employment roles, leisure activities, social roles and sporting activities. The HiMAT was developed to quantify high-level mobility outcomes following traumatic brain injury (TBI). The HiMAT items were generated from existing adult and paediatric neurological mobility scales and the opinions of expert clinicians (Williams et al., 2005a), before being tested on a cohort of people with TBI. The final HiMAT items are unidimensional and can be used to quantify high-level mobility on people with severe cognitive impairment. The HiMAT is suitable for any TBI clients who have goals which require a level of mobility beyond independent level walking.

The HiMAT was developed as a unidimensional measure of motor performance rather than a general measure of functional mobility. Functional mobility for activities such as shopping or sport requires the integration of motor, cognitive and behavioural control mechanisms. A unidimensional scale of mobility, used in conjunction with other measures of cognitive, behavioural and emotional status, could assist clinicians to identify the reasons why participation in pre-morbid physically demanding activities is restricted. In turn this could enable clinicians to more easily quantify mobility restrictions.

Few scales used in TBI are able to quantify high-level mobility, even though it is well recognized that people with TBI experience difficulty in performing tasks such as running and jumping. Williams, Robertson and Greenwood (2004a) identified 175 TBI outcome studies published from 1990 through to May 2004 that reported on mobility outcome. Their main findings can be summarized as follows:

  • Specific measures of mobility are seldom used. Only 8 (4.6%) of the 175 outcome studies used a mobility measurement scale. These eight studies used seven different mobility measures.
  • The mobility scales that are used have been developed in elderly or stroke populations and have a substantial ceiling effect. The Rivermead Mobility Index (RMI) was the only scale used, reported in only one study in TBI, that extends mobility beyond walking tasks and stair use.
  • Together, measures designed for the inpatient phase of rehabilitation, such as the FIM, Disability Rating Scale (DRS) and Barthel Index, were used in 96 (54.9%) of the 175 outcome studies. These measures were used to report outpatient or long-term outcomes, an application for which they were not designed.
  • Twelve different measures of participation were used to report physical outcome. When used on their own, measures of participation are unable to identify the restriction leading to reduced participation following TBI.

Williams, Robertson and Greenwood (2004a) showed that little is known about the extent of high-level mobility limitations following TBI. Although independent mobility is an important goal of rehabilitation, outcome studies often fail to measure it. When mobility is measured, the scales used suffer from a ceiling effect and fail to extend mobility to age-appropriate levels for return to physically demanding employment roles, leisure activities, social roles and sporting activities. A new high-level mobility scale was needed to quantify motor performance to the high-level required for such activities.

The HiMAT was developed over several years of research (Williams et al., 2005a; Williams et al., 2005b). In the initial stages, a literature review was conducted to determine the range of existing high-level items on adult and paediatric neurological mobility scales. To further extend the pool of high-level mobility items, a consensus method was used to survey the opinions of expert physiotherapists and physical educators. This process resulted in a group of 20 high-level mobility items that were prepared for testing on TBI clients.

One hundred and three people with TBI were recruited from Epworth Hospital, Melbourne, Australia. Inclusion criteria were; 1) the ability to walk independently without a gait aid, 2) diagnosis of a TBI, 3) willing and able to provide informed consent, 4) no diagnosis of hypoxic brain damage, cerebrovascular accident, or a concurrent pre-existing central nervous system disorder. Patients who were unable to follow two-stage commands were excluded, as were those with severe behavioural problems that restricted their ability to participate in the testing procedures. Rasch analysis was used to investigate the content validity and unidimensionality of the HiMAT.

The HiMAT consists of 13 items that are measured using either a stopwatch or tape-measure. Measures obtained on each item are scored and summed for a total HiMAT score (maximum score 54). Higher scores indicate better mobility performance. Depending on the ability of the client and how many items they can perform, testing takes 5-15 minutes. No formal training is required to administer the HiMAT. The HiMAT has been developed and validated in TBI for clients who have high-level mobility goals, or whose goals required advanced mobility. Although clinically it is being used in CVA, Multiple Sclerosis, Spinal Cord Injuries and Cerebral Palsy, it is yet to be validated in these populations.

Permission to use the HiMAT is not required but the principal investigator, Gavin Williams PhD would appreciate prospective user’s of the scale to contact him so the its application can be tracked for location and population type.
For further information, please contact:
Gavin Williams, PhD
Senior Physiotherapist, Epworth Rehabilitation
89 Bridge Rd
Richmond 3121
Victoria, Australia
Ph: 011 (613) 9426 8727
F: 011 (613) 9426 8734

Information regarding the HiMAT was contributed by Epworth Rehabilitation. Please contact Gavin Williams, Ph.D., at for more information.

If you find the information in the COMBI useful, please mention it when citing sources of information. The information on the HiMAT may be cited as:

Williams, G. (2006). The High Level Mobility Assessment Tool. The Center for Outcome Measurement in Brain Injury. ( accessed ).


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