Article Full Title
The Effect of Velocity of Joint Mobilization on Corticospinal Excitability in Individuals with a History of Ankle Sprain
Author Names
Fisher, B; Piraino, A; Lee, Y; Smith, J; Johnson, S; Davenport, T; Kulig, K
Reviewer Name
Andres Carro SPT
Reviewer Affiliations
Duke Doctor of Physical Therapy
Paper Abstract
Study Design: Controlled laboratory study.
Background: Joint mobilization and manipulation decrease pain and improve patient function. Yet, the processes underlying these changes are not well understood. Measures of corticospinal excitability provide insight into potential mechanisms mediated by the central nervous system.
Objectives: To investigate the differential effects of joint mobilization and manipulation at the talocrural joint on corticospinal excitability in individuals with resolved symptoms following ankle sprain. Methods Twenty-seven participants with a history of ankle sprain were randomly assigned to the control, joint mobilization, or thrust manipulation group. The motor-evoked potential (MEP) and cortical silent period (CSP) of the tibialis anterior and gastrocnemius were obtained with transcranial magnetic stimulation at rest and during active contraction of the tibialis anterior. The slopes of MEP/CSP input/output curves and the maximal MEP/CSP values were calculated to indicate corticospinal excitability. Behavioral measures, including ankle dorsiflexion and dynamic balance, were evaluated.
Results: A repeated-measures analysis of variance of the MEP slope showed a significant group-by-time interaction for the tibialis anterior at rest (P = .002) and during active contraction (P = .042). After intervention, the thrust manipulation group had an increase in corticospinal excitability, while the corticospinal excitability decreased in the mobilization group. The thrust manipulation group, but not other groups, also demonstrated a significant increase in the maximal MEP amplitude of the tibialis anterior after intervention.
Conclusion: The findings suggest that joint manipulation and mobilization have different effects on corticospinal excitability. The increased corticospinal excitability following thrust manipulation may provide a window for physical therapists to optimize muscle recruitment and subsequently movement. The trial was registered at ClinicalTrials.gov (NCT00847769). J Orthop Sports Phys Ther 2016;46(7):562-570. Epub 6 Jun 2016. doi:10.2519/jospt.2016.6602
NIH Risk of Bias Tool
Quality Assessment of Controlled Intervention Studies
Was the study described as randomized, a randomized trial, a randomized clinical trial, or an RCT
No
Was the method of randomization adequate (i.e., use of randomly generated assignment)?
Yes
Was the treatment allocation concealed (so that assignments could not be predicted)?
No
Were study participants and providers blinded to treatment group assignment?
No
Were the people assessing the outcomes blinded to the participants’ group assignments?
Yes
Were the groups similar at baseline on important characteristics that could affect outcomes (e.g., demographics, risk factors, co-morbid conditions)?
No
Was the overall drop-out rate from the study at endpoint 20% or lower of the number allocated to treatment?
Yes
Was the differential drop-out rate (between treatment groups) at endpoint 15 percentage points or lower?
Yes
Was there high adherence to the intervention protocols for each treatment group?
Cannot Determine, Not Reported, or Not Applicable
Were other interventions avoided or similar in the groups (e.g., similar background treatments)?
Yes
Were outcomes assessed using valid and reliable measures, implemented consistently across all study participants?
Yes
Did the authors report that the sample size was sufficiently large to be able to detect a difference in the main outcome between groups with at least 80% power?
No
Were outcomes reported or subgroups analyzed prespecified (i.e., identified before analyses were conducted)?
Cannot Determine, Not Reported, or Not Applicable
Were all randomized participants analyzed in the group to which they were originally assigned, i.e., did they use an intention-to-treat analysis?
Cannot Determine, Not Reported, or Not Applicable
Key Finding #1
Corticospinal excitability of the tibialis anterior increased after high-velocity talocrural thrust manipulation for approximately 30 minutes after the intervention.
Key Finding #2
Corticospinal excitability of the tibialis anterior decreased after low-velocity talocrural mobilization.
Please provide your summary of the paper
The authors of this article sought to determine the effects of talocrural mobilization and manipulation on the corticospinal excitability measured in the gastrocnemius and the tibialis anterior on those who have a history of ankle injury but whose symptoms have resolved. The motor evoked potential (MEP) and cortical silent period slopes and values obtained post-intervention were compared to a control of manual contact. The results of the study showed that corticospinal excitability increased in the tibialis anterior after high-velocity thrust manipulation, but was decreased in the tibialis anterior after low-velocity mobilization. In the gastroc there were no significant changes. The corticospinal increase in excitability of the tibialis anterior lasted approximately 30 minutes following thrust intervention, which may have clinical significance for skill acquisition and movement modulation. One limitation to this study is that the corticospinal excitability was only tested at a single point in time following the interventions, so the actual duration of the effect on the corticospinal tract is unknown and should be further investigated.
Please provide your clinical interpretation of this paper. Include how this study may impact clinical practice and how the results can be implemented.
This article provides clinically significant results for corticospinal excitability in the tibialis anterior, showing that it increased following talocrural high-velocity thrust manipulation. The finding that corticospinal excitability of the tibialis anterior increased has implications that using this intervention may contribute to added potential for motor recruitment of that muscle. Additionally, the finding that this increase lasted at least 30 minutes has clinical significance in that this added motor recruitment potential can be utilized immediately after the intervention during exercise therapy sessions to encourage skill acquisition and may even result in an added strength effect in the long term due to the additional motor recruitment during exercise immediately following the intervention. More research on the long-term effects of this corticospinal excitability change on strength changes and skill acquisition when the intervention is used over multiple sessions would need to be done to determine the clinical effectiveness on function. More research would also need to be done on populations that are more symptomatic in order to make the findings more clinically relevant to general physical therapy patient populations.
