The Modified Hammersmith Functional Motor Scale for Children with Spinal Muscular Atrophy (MHFMS-SMA) (Krosschell, et al 2006) is an adaptation of the original Hammersmith Functional Motor Scale for Children with SMA (Main et al, 2003). The original Hammersmith Functional Motor Scale for Children with SMA was modified to establish a standard measure of functional ability in children with non-ambulant spinal muscular atrophy Types II and III for use in longitudinal multi-center clinical trials. Concrete operational definitions were developed and scoring criteria were clarified to minimize potential ambiguities in the administration and scoring of the test. In addition, after a pilot study, item order was modified to minimize position changes and to decrease fatigue and undue stress on the children during testing (Krosschell et al, 2006). The MHFMS is currently in use to assess gross motor abilities of non-ambulant children with SMA in multiple research trials as well as in clinical settings.
The MHFMS-Extend was later developed to address ceiling effects in stronger ambulant children with SMA. The MHFMS-Extend consists of the MHFMS and an exteded gross motor module and was developed to allow for assessment of stronger children with SMA Type II and for assessment of ambulant children with SMA Type III. Items selected for the MHFMS-Extend were chosen based on functional, clinical and research applicability after careful assessment of a large group of children with SMA Type III and a group of stronger Type II children. Additional test modules include a Timed Test Module and a Fine Motor Module. The test manuals for each were developed to assure standardized assessment in clinical trials and to allow for training of new trial evaluators and clinicians working with children with SMA.
The MHFMS Test manual was developed prior to the initiation of Project Cure SMA’s first clinical trial, the CARNIVAL trial, and was initially used for training therapists for use in a Natural History Study of Children with SMA as well as in preparation for the CARNIVAL Trial. The MHFMS demonstrates a ceiling affect when used with individuals with SMA who are ambulatory. The MHFMS-Extend and the Timed Test and Fine Motor modules were therefore developed to address function in the ambulant Type III population (MHFMS-Extend, Timed Test Modules) and the Fine Motor Module was developed to assess upper extremity function in those with Type II and Type III SMA.
The MHFMS and MFHMS-Extend, as well as the Timed Test and Fine Motor modules, are currently in use in multiple research trials and clinical settings. It is our hope that this website will allow you to familiarize yourself with the MHFMS and the MHFMS-Extend assessment tools. There is a list of general directions for all tests, as well as a detailed equipment list. In addition, there are some additional directions that are applicable only to the MHFMS-Extend modules. Within each individual manual pictures as well as video clips provide examples of start and stop positions, and scoring criteria for each item. These tests are intended to be used for individuals with SMA and should be carried out by evaluators who are familiar with and have experience with this population. The reliability and validity of the scales have been documented. The MHFMS-Extend is currently undergoing additional psychometric analysis using Rasch analysis to further refine the scale's clinical and research validity, reliability and robustness. Evaluators should understand and perform all assessments utilizing the described operational definitions, test order and start and stop positions. Training to ascertain reliability prior to use in clinical research setting is recommended.
If you have any questions while exploring our site or any questions about the MHFMS, MHFMS-Extend or additional test modules please feel free to contact us.
Kristin Krosschell, PT, MA, PCS
Jo Anne Maczulski, MA, OTR/L