EK scale

The EK scale was developed by RCFM co-founder, physiotherapist, PhD Birgit Steffensen as an instrument to measure changes  – even small ones – in physical function over time in wheelchair users with spinal muscular atrophy and Duchenne muscular dystrophy.

The scale is based on interviews in which the person in question accounts for his or her functional capacity. The name EK stands for egenklassifikation meaning self classification.

EK scale in Danish

Development of EK 1

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 to 3 based on a face-to-face interview with the person about how the individual 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) represents highest function.

A more sensitive scale (EK2)

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 as for EK1, but the maximum EK2-sum score is 51.
The EK scale is used worldwide and has been translated into and validated in several languages.

The content validity, reliability and discriminatory power of EK2 was good, meaning that the categories of EK 17 have stronger explanatory power than the categories of Ek 1-10 in a non-ambulant population of persons with SMA


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.

Translations in progress

Japanese version

Contact: shigemori@ncnp.go.jp

Mexican version

Contact: ian12_rm619@hotmail.com

Hebrew version

Contact: Lynette.Aleman@tribeclinical.com

Arabic version

Contact: Lynette.Aleman@tribeclinical.com

  • Ulla Werlauff

    Head of research, physical therapist, MSc, ph.d

    - Project management and supervision
    - Measurement instruments
    - Method
    - Education
    Læs mere

We are a center of excellence for neuromuscular diseases (NMD).

We believe in seing the entire person with NMD in a life-long perspective. That way, we can help create the best environment for people with NMD and their families. 

We share our knowledge with our patients, their families and our professional partners. We work interdisciplinary and across sectors.


Kontakt os

E-mail: info@rcfm.dk
Tel: +45 8948 2222

CVR-nr: 88502728

Head quarters
Kongsvang Allé 23
DK-8000 Aarhus C



Sealand department
Blekinge Boulevard 2, 1.sal
DK-2630 Taastrup