title: Modulating Cortical Excitability to Improve Functional Movements in Individuals with Patellofemoral Pain: A Randomized Controlled Trial
Creators: name: Aquino, Jeno
name: Broadwell, Bryce
name: Wallace, Connan
name: Whimple, Makenzie
Publisher: name: University of Nevada, Las Vegas
publisherIdentifier: https://ror.org/0406gha72
publisherIdentifierScheme: ROR
Year: 2024

description: "<p>Purpose/Hypothesis: Persons with patellofemoral pain (PFP) often exhibit increased knee valgus during functional tasks that is traditionally addressed by strengthening weak hip musculature. However, research related to this topic has revealed altered cortical reorganization in individuals with PFP contributes to dysfunctional movements and underscores the critical role of central neural control in this condition. Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that alters cortical excitability to enhance neuroplasticity. Research using tDCS priming supports its feasibility as a possible treatment for other musculoskeletal conditions. However, its application specifically targeting the corticomotor function of the gluteal musculature in individuals with PFP has not been investigated. The purpose of this study was to investigate the acute effects of tDCS plus exercise to affect frontal plane kinematics during functional tasks in persons with PFP. We hypothesized that with tDCS priming, exercise would be more effective at improving frontal plane kinematics when compared to sham stimulation paired with exercise in persons with PFP.</p>
<p>Participants: Ten persons with unilateral or bilateral PFP. If bilateral PFP was the presentation, the involved limb was determined as being the more symptomatic side for a longer period of time. (6M/4F, age=28.2±6.88 yrs, BMI=26.83± 6.67). </p>
<p>Materials and Methods: Participants attended 2 sessions in which tDCS or sham stimulation was delivered using a bihemispheric montage with the anode over the primary motor cortex contralateral to the affected limb. During these conditions, participants performed four different hip strengthening exercises. Before and after each session, participants performed 5 functional tasks (single leg squat, single leg landing, single leg hop, forward step down, and lateral step down) on the symptomatic leg recorded in a frontal plane view. Pain on a visual analog scale (VAS) was also recorded. Kinematics were measured for each task, including trunk lean angle (TLA), hip and knee frontal plane projection angles (FPPA), and dynamic valgus index (DVI) at peak knee flexion. A one-way ANOVA with repeated measures and post-hoc pairwise comparisons was employed to compare the kinematics, while a Friedman test was used to compare VAS across the 3 conditions (pre-intervention, post-tDCS, and post-Sham).</p>
<p>Results: No significant difference in TLA, hip FPPA, knee FPPA, or DVI was found among the 3 conditions during single leg squat, single leg hop, forward step down, and lateral step down (p>0.05). While knee FPPA was significantly lower post-Sham compared to pre-intervention during single leg landing (pre-intervention=7.73°±5.95°; post-Sham=3.70°±6.18°; p=.018), this change was less than calculated standard error of measurement. VAS scores were not different among the 3 conditions (p=.147).</p>
<p>Conclusions: A single session of tDCS with exercise was ineffective at improving frontal plane kinematics and reducing pain while performing functional tasks in persons with PFP when compared to exercise alone.</p>
<p>Clinical Relevance: Additional studies are needed to provide a more comprehensive understanding of the potential outcomes associated with tDCS in persons with PFP.</p>"