Long-term self-stretching increases muscle length in chronic hemiparesis 2

In stroke-induced hemiparesis, muscles such as the plantar flexors undergo dramatic alterations that involve both physical shortening (decrease in fascicle length) and viscoelastic loss of extensibility (Kwah et al., 2012). This muscle disorder has been termed spastic myopathy (Gracies, 2015) and is commonly treated with stretching techniques. However, the effectiveness of stretching techniques for treating spastic myopathy has been questioned and the long-term effects (>6 months) are unknown (Harvey et al., 2017).

In a recent retrospective study, we observed marked improvements in passive range of motion for six lower limb muscles, including plantar flexors, in patients with chronic spastic paresis who performed stretching and exercises using a Guided Self-rehabilitation Contract (GSC). GSC is an antagonist-targeting rehabilitation system performed daily at home with compliance monitored using a diary. Static stretches of the target muscles are performed at high load for a cumulative period of ≥ 10 min/day per muscle. Exercises consist of unassisted rapid movements at maximum force against each targeted antagonist in a short time (Gracies et al, 2019).

The present study was a prospective, randomised controlled trial comparing ultrasonographic structural changes and clinical assessments in the soleus and medial gastrocnemius muscles in patients with chronic hemiparesis after receiving 1-year of conventional therapy (control) or conventional therapy plus daily self-stretching using the GSC programme.

WHAT DID WE FIND?

We found that, after 1 year, fascicle length (mm) of the soleus (18 (9-27)) and medial gastrocnemius (6 (4-9)) muscles increased more in participants in the GSC plus conventional therapy group compared to conventional therapy alone. Thickness (mm) of the soleus (5 (3-8)) and medial gastrocnemius (2 (0-4) also increased more in the GSC group compared to the conventional therapy group.

Measurements of clinical passive muscle extensibility improved more in the GSC group as well, with the greatest improvements observed for the rectus femoris (10° (0-18)) and medial gastrocnemius (7° (2-11)) muscles. A positive correlation was also noted between changes in soleus extensibility at 1-year and the diary-based reported daily time of soleus stretching.

SIGNIFICANCE AND IMPLICATIONS

This study confirmed for the first time that a long-term self-stretch program in patients with chronic hemiparesis partially reversed architectural and clinical manifestations of spastic myopathy. This study also contributed to the design of a large, multicenter, randomised controlled trial (NEURORESTORE) which is currently investigating the effect of a 1-year GSC plus conventional therapy intervention on upper and lower limb function in patients with chronic hemiparesis (Gracies et al, 2019).

PUBLICATION REFERENCE

Pradines M, Ghedira M, Portero R, Masson I, Marciniak C, Hicklin D, Hutin E, Portero P, Gracies JM, Bayle N. (2019). Ultrasound Structural Changes in Triceps Surae After a 1-Year Daily Self-stretch Program: A Prospective Randomized Controlled Trial in Chronic Hemiparesis. Neurorehabil Neural Repair, 33(4): 245-259.

KEY REFERENCES

Gracies JM. (2015). Coefficients of impairment in deforming spastic paresis. Ann Phys Rehabil Med, 58(3):173-178.

Gracies JM, Pradines M, Ghédira M, et al. (2019). Guided Self-rehabilitation Contract vs conventional therapy in chronic stroke-induced hemiparesis: NEURORESTORE, a multicenter randomized controlled trial. BMC Neurol, 19(1):39.

Harvey LA, Katalinic OM, Herbert RD, et al. (2017). Stretch for the treatment and prevention of contracture: an abridged republication of a Cochrane Systematic Review. J Physiother, 63(2):67-75.

Kwah LK, Herbert RD, Harvey LA, et al. (2012). Passive mechanical properties of gastrocnemius muscles of people with ankle contracture after stroke. Arch Phys Med Rehabil, 93(7):1185-1190

Pradines M, Baude M, Marciniak C, et al. (2018). Effect on passive range of motion and functional correlates after a long-term lower limb self-stretch program in patients with chronic spastic paresis. PM R, 10(10):1020-1031

AUTHOR BIO

Maud Pradines is a physiotherapist and a Postdoctoral Fellow at Henri Mondor Hospital, Créteil, France. Her research investigates the characterisation of the muscle disorder in spastic paresis and its impact on neural command and motor function. She also explores various techniques to prevent and treat this muscle disorder, called spastic myopathy.