Efficacy of Focused Shock Wave Therapy Before and After Botulinum Toxin Injection in Patients With Post-Stroke Spastic Equinus/Equinovarus Foot: A Randomized Clinical Trial

Stroke is one of the leading causes of long-term disability worldwide. Lower limb spasticity develops in a substantial proportion of stroke survivors, with the spastic equinovarus foot representing the most common gait pattern impairment. This condition negatively affects walking ability, balance, activities of daily living, and quality of life.

Botulinum toxin type A (BoNT-A) is considered the standard treatment for focal post-stroke spasticity. Nevertheless, its clinical effect is temporary and additional therapeutic strategies are needed to optimize and prolong treatment benefits. Extracorporeal shock wave therapy (ESWT) is a non-invasive intervention that has demonstrated beneficial effects on muscle tone, muscle stiffness, pain, and functional recovery. Experimental and clinical evidence suggests that ESWT may enhance the effects of BoNT-A, although the optimal timing of ESWT administration has not yet been established.

This study is a prospective, randomized, single-blind, three-arm clinical trial conducted at the Department of Physical and Rehabilitation Medicine of Hospital Clínico San Carlos (Madrid, Spain). Participants with chronic post-stroke spastic equinovarus foot who meet the eligibility criteria will be randomly assigned to one of three treatment groups:

Group A: BoNT-A injection alone.

Group B: One session of focal ESWT immediately before BoNT-A injection.

Group C: BoNT-A injection followed by one session of focal ESWT two weeks later. PROYECTO TESIS.docx

The primary outcome is lower limb spasticity measured using the Modified Ashworth Scale (MAS). Secondary outcomes include the Modified Tardieu Scale, passive ankle dorsiflexion range of motion, muscle strength measured by the Medical Research Council (MRC) scale, gait performance assessed by the 10-Meter Walk Test (10MWT) and Functional Ambulation Classification (FAC), pain assessed by the Visual Analogue Scale (VAS), patient-reported function using the Patient-Specific Assessment Scale (PSAS), muscle echogenicity using the Heckmatt scale, and muscle stiffness evaluated by real-time elastography. PROYECTO TESIS.docx

Clinical and ultrasound evaluations will be performed at baseline and at 4, 12, 24, 28, 42, and 54 weeks after treatment. The findings are expected to clarify whether the timing of focal ESWT administration influences the effectiveness of BoNT-A in the treatment of post-stroke spastic equinovarus foot and may contribute to optimizing rehabilitation protocols.

Inclusion criteria

• Adults aged 18 to 87 years.
• Clinical diagnosis of chronic stroke.
• Presence of unilateral spastic equinovarus foot.
• Lower-limb spasticity requiring treatment with botulinum toxin type A.
• Ability to understand the study procedures and provide written informed consent.

Exclusion criteria

• Botulinum toxin type A injection in the affected lower limb within the previous 12 weeks.
• Previous extracorporeal shock wave therapy in the affected lower limb within the previous 12 weeks.
• Fixed ankle contracture preventing passive correction.
• Other neurological or musculoskeletal disorders affecting gait assessment.
• Pregnancy or breastfeeding.
• Contraindications to botulinum toxin type A or extracorporeal shock wave therapy.
• Severe cognitive impairment preventing participation or informed consent.
• Participation in another interventional clinical trial.