The Effect of Additional Neurodynamic Intervention in Patients With Chronic Ankle Instability
Phase: NA
Conditions: Ankle Sprains
Sponsor: National Yang Ming Chiao Tung University

Study Protocol with Statistical Analysis Plan 
 
 
The effect of additional neurodynamic intervention  
in patients with chronic ankle instability 
 
 
 
 
NCT number: NCT05090423 
Authors: Hsin-I Chen, Yi-Fen Shih 
Department of Physical Therapy and Assistive Technology, National Yang 
Ming Chiao Tung University 
 
 
 
July 22, 2024 
 
 
 
 

Background: Chronic ankle instability (CAI) is characterized by pain, repeated 
sprains and giving way. Approximately 40% of acute ankle sprain would develop into 
chronic ankle instability. Recently, the pathomechanical impairment, sensory-
perceptual impairment and motor-behavioral impairment have been documented in 
the chronic ankle instability model. Previous research revealed that compared to the 
control subjects, people with CAI had lower pressure pain threshold (PPT). This 
increased mechanosensitivity of the neural tissues around the ankle might account for 
pain and dysfunction in people with CAI. Pahor et al., indicated that in subjects 
following ankle inversion sprain there is greater restriction of knee extension on the 
injured side compared to non-injured side in the slump test with the ankle plantar 
flexion and inversion, which may suggest the restriction in mobility of the common 
peroneal tract. However, the effects of neurodynamic intervention, which addresses 
the mechanosensitivity problems, in people with CAI are still unclear. Purpose: The 
aim of the study is to investigate the effects of neurodynamic intervention on the 
mechanosensitivity, balance performance and self-reported function in patients with 
CAI. Study design: A randomized controlled trial design. Single-blinded. Methods: 
Forty subjects between 20-50 with CAI were recruited and randomized into either the 
exercise only group or the neurodynamic intervention with exercise (neurodynamic) 
group. The sample size was calculated based on the PPT data of Lorenzo-Sanchez-

Aguilera et al’s, which requires 20 subjects in each group to reach a statistical power 
of 0.8. Both groups were receive 12 interventions within 6-8 weeks. The exercise only 
group performed balance training, while the neurodynamic group received balance 
training and neurodynamic intervention for the common peroneal nerve. Outcome 
measures included demographic data, pressure pain threshold, active knee extension 
range of motion (ROM) of the slump test with ankle plantarflexion and inversion 
(AKEOST), hamstrings flexibility, ankle range of motion, Y balance test and foot and 
ankle ability measure (FAAM). All data were assessed and collected before and after 
12 interventions. Statistics analysis: Two-way repeated measures analysis of 
variance (ANOVA) was used to examine the intervention effect with the alpha level 
set at 0.05.