EK scale

The Egen Klassifikation (EK) is an outcome measure to determine functional ability in non-ambulant persons with Duchenne muscular dystrophy and spinal muscular atrophy. The scale relates to the natural courses of disease and each item represents daily activities relevant for the patient; it is clinical relevant to all non-ambulatory persons with DMD or SMA.

Construction of the scale

The EK1-10 was developed and constructed by Dr Birgit Steffensen et al; studies on reliability and validity were published 1995-2002 [1,2,3,4]. The EK1-10 is very responsive to change in persons with DMD [5].

The scale is a composite scale consisting of 10 items; each item is scored in four categories from 0-3, based on a face-to-face interview with the person about how the individually items are normally performed; if possible the person is asked to demonstrate the performance. The EK-sum score is calculated as the sum of all items; maximum score (30) represents lowest function, and minimum score (0) represent highest function.
Since the EK1-10  was not as sensitive to change over time in individuals with SMA as in individuals with DMD, the EK scale was expanded to EK2 1-17  by an international expert group . Seven items representing abilities related to hand-function, eating and swallowing were added to the original scale [6]; the scoring by four categories and the revised score with 0 as highest function is the same, but the maximum EK2-sum score is now 51.
The EK scale is used worldwide and has been translated and validated into several languages.

  1. Lyager S, Steffensen B, Juhl B. Indicators of Need for Mechanical Ventilation in Duchenne Muscular Dystrophy and Spinal Muscular Atrophy.Chest 1995;108:779-785.
  2. Steffensen B, Hyde S, Lyager S, Mattsson E. Validity of the EK scale: a functional assessment of non-ambulatory individuals with Duchenne muscular dystrophy or spinal muscular atrophy. Physiotherapy Research International, 6(3) 119–134, 2001.
  3. Steffensen BF, Lyager S, Werge B, Rahbek J, Mattsson E. Physical capacity in non-ambulatory people with Duchenne muscular dystrophy or spinal muscular atrophy. A longitudinal study. Dev Med Child Neurol. 2002; 44:623-32.
  4. Steffensen BF, Hyde S, Attermann J, Mattsson E. Reliability of the EK Scale, a Functional Test for Non-ambulatory Persons with Duchenne Dystrophy. Advances in Physiotherapy 2002; 4:37-47.
  5. Connolly AM et al. Clinical trial readiness in non-ambulatory boys and men with Duchenne muscular dystrophy: MDA-DMD network follow-up. Muscle Nerve 2016; 54: 681-689.
  6. Steffensen BF, Mayhew A, Aloysius A, et al. Egen Classification revisited in SMA. Neromuscul Disord 2008; 18: 740-41.

English versions and manual

The English version of the EK1-10 scale was first published in Physiotherapy Research International 2001, EK-validity study .

During the development of the EK scale, the scale proved to be an indicator of the need for mechanical ventilation in persons with DMD. This study was published in Chest 1995

The EK2 was expanded with seven items to make the scale more sensitive to changes in SMA, and the study was presented as a poster presentation at WMS 2008. The manual was updated by Anna Mayhew PT, PhD, Newcastle University.

You can download the EK2 scale and the EK2 manual here.

The EK scale is translated and validated in several languages. This webpage will inform about the translations with references to the authors and their publications.

The scale can be used free of cost, but we would appreciate to learn about validations and publications. Please contact Ulla Werlauff/ ulwe@rcfm.dk

Spanish version

The Scale – Escala-EK2

Fagoaga J, Girabent-Farrés M, Bagur-Calafat C, Febrer A, Steffensen BF. Translation and validation of the Egen Klassifikation scale for the Spanish population: functional assessment for non-ambulatory individuals with Duchenne’s muscular dystrophy and spinal muscular atrophy. Rev Neurol. 2013 Jun 1;56(11):555-61. Link to article   

Fagoaga J, Girabent-Farrés M, Bagur-Calafat C, Steffensen BF.Evolution of functional capacity, assessed with the Egen Klassifikation scale, in the Spanish population with spinal muscular atrophy or Duchenne muscular dystrophy. A three year longitudinal study. Rev Neurol. 2013 Jun 1;56(11):555-61. Link to article

Fagoaga J, Girabent-Farrés M, Bagur-Calafat C, Febrer A, Steffensen BF. Evaluación funcional para personas no ambulantes afectas de atrofia muscular espinal y distrofia muscular de Duchenne. Traducción y validación de la escala Egen Klassifikation 2 para la población española. Rev Neurol 2015; 60 (10): 439-446 – Link to article in Revista de Neurología

Manual del Usuario para la escala EK2

Contact : joaquinfagoaga@gmail.com

Turkish version

The scale – Egen Klassifikasyonu Skalası Versiyon 2

Alemdaroğlu I, Karaduman A, İyigün-Yatar G, Tunca-Yılmaz Ö, Topalo H. Turkish version of the Egen Klassifikation scale version 2: validity and reliability in the Turkish population. The Turkish Journal of Pediatrics 2014;56:643-650. Link to article

Contact: aykaradu@hacettepe.edu.tr

Portuguese version

The scale – EK

Martinez JAB, Runherotti MA,  De Assis MR et al. Validacao da escala motora functional EK para a lingua Portuguesa. Rev Assoc Med Bras 2006; 52(5): 347-51

Contact: jabmarti@fmrp.usp.br

Ongoing validations

Japanese version

Contact: shigemori@ncnp.go.jp

Mexican version

Contact: ian12_rm619@hotmail.com


The EK scale can discriminate between subjects with different level of functional ability and can capture small changes in physical function.

(the following list will be updated)

SMA studies

Physical characteristics and applicability of standard assessment methods in a total population of spinal muscular atrophy

The applicability of four clinical standard methods to evaluate arm and hand function in all stages of SMA II

Change in muscle strength over time in spinal muscular atrophy type II

DMD studies

Correlation of EK and Barthel Index score

Connolly Am et al. Clinical trial readiness in non-ambulatory boys and men with duchenne muscular dystrophy: MDA-DMD network follow-up”. Muscle Nerve 2016 Oct;54(4):681-9