Stroke Training and Awareness Resources (STARs)


Muscle lengthening

‘Stretching normal muscle leads to mechanical changes in shape through creep’
(Gelinas et al, 2000)

Creep

A progressive deformation when a constant load is applied over time; it allows soft tissues to tolerate applied loads by lengthening.

  • Holding the stretch for a length of time, repeatedly, leads to permanent lengthening of muscle.
  • We know that repeated stretching for long enough to allow tissue lengthening, leads to change in the physical structure of the muscle. However we don’t know what the optimum time is to get the best effect.
  • Recommended time varies from 30 mins (Tardieu et al, 1988) to 6 hours (Williams, 1989).
  • We also need to consider the effect on the opposing muscle groups. Muscle groups work by allowing opposite movements when one group is active the other is relaxed – e.g. if you stretch hamstrings for prolonged periods you are effectively exposing quads to the effects of immobility in a shortened position.

The Tardieu study found that after 30 mins stretching, sarcomeres got longer and more in number. This increase in number was greater with a stretch of 2 hours. The treatment time must be realistic so you must consider if it is achievable in the setting be it hospital or home.

Guissard et al, 2004, found in healthy subjects, that passive stretching (10 minutes of stretching a day for 30 days over 6 weeks) can reduce the tendon’s sensitivity to stretch.

The Williams study looked at prevention of soleus contracture and found that to prevent soleus shortening in individuals with stroke and spasticity, the muscle had to be in a lengthened position for 6 hours per day – is this achievable in hospital or community setting? It certainly is a lot to ask any individual to take out of their day. It also may not be applicable to many of our patients or clients. However stretching remains important and regular stretching should be part of the patients treatment plan for reducing spasticity and to protect movement of joints.

Goals of the treatment are important- if your patient is aiming for weight bearing, gait or transferring in standing on to walking then it matters a lot. If your patient is aiming to be able to sit in a wheelchair and is hoist transferred then it may not be as important for function but could lead to complications from contractures including pain and tendon shortening. Remember to ask what the patient’s self-management goals are in relation to movement and lifestyle.

Page last reviewed: 04 May 2020