The Revised Hammersmith Scale for SMA was published in February 2017.  It is based upon the original Hammersmith Scale.  The Hammersmith scale is a well recognised functional scale used clinically and in clinical trials across the world to measure physical abilities of children and adults with SMA type 2 and 3, so why did we decide to change it? 

In 2014 the original scale and several other SMA scales received some criticism regarding how well they met a number of measurement criteria i.e. how well it measures the physical abilities of those with SMA, how well the scoring works, how reliable the scale was etc. and it was recommended that the scale and others required revision (Cano et al, 2014).  At that time SMA clinical trials were increasing and we were entering a time where instead of a disease which could be described as having initial period of decline followed by relative stability there may be the potential for people with SMA to improve.  

Therefore an international SMA consortium consisting of SMA REACH UK, the Italian SMA Network and the PNCRN for SMA (USA) networks met to review and enhance the Hammersmith Scale so that it was fit for purpose for today's climate.  This resulted in the development of the Revised Hammersmith Scale for SMA (RHS).  Each item and it's scoring was derived following in depth discussion by a panel of SMA experts and then tested in several pilots until the final, published, version was created.

The RHS consists of 36 items which test those with SMA type 2 who may have lost the ability to sit through to very strong people with SMA type 3.  The maximum achievable score is 69.  The scoring has been rigorously tested with complex psychometric tests in a large international pilot of 138 people with SMA.  It also includes two timed tests to really test those with stronger abilities.  It also includes reference to the World Health Organisation motor milestones which are currently used in clinical trials. The manual (including the testing form) can be found here, and the published article (which also includes the testing form) is free to download and access from the PLOS ONE website.

The Hammersmith Functional Motor Scale (HFMS) was originally developed to assess the physical abilities of children with non-ambulant Spinal Muscular Atrophy, it was developed by Marion Main and colleagues at the Hammersmith Hospital in 2003.  It consists of 20 items which they felt were important to to measure the physical functioning of those with SMA type 2 and those who are SMA type 3 who are no longer independently mobile, and was ordered in level of item difficulty.  The physiotherapist asks the person with SMA to do a specific activity such as rolling and they then grade the quality and execution of that movement on a scale of 0 being unable, 1 performed with some compensation, and 2 unaided.  The total score achievable on the orginal HFMS is 40 (Main et al, 2003).  ​