Development of a Passive Upper Extremity Orthosis for Amyoplasia

Student thesis: Master thesis (including HD thesis)

  • Joakim Raunsbæk
  • Jan Nørgaard Lund
  • Erik Føge Jensen
4. semester, Sports Technology, Master (Master Programme)
Those who are born with amyoplasia are typically not able to perform activities of daily living (ADL) due to decreased
muscle mass, joint contractures, and unnatural limb positioning. It is possible to use an orthosis to aid in ADL and
increase their independency. A passive orthosis can support the weight of their arm against gravity, allowing them to
perform movements with less muscle force. This study presents a prototype design that uses musculoskeletal modeling
to optimise spring stinesses to gravitationally balance the arm while compensating for the excessive internal rotation
of the glenohumeral joint. A subject-specic musculoskeletal was developed to simulate the eects of the orthosis
during ADL. The simulations showed that a biarticular spring with a stiness of 233.33 Nm􀀀1 was able to lower the
maximal muscle activity to a level in which tasks of ADL can potentially be performed.
Publication date7 Jun 2017
Number of pages80
ID: 259304919