Clinical Scenario: Ankle sprains are the most prevalent athletic-related musculoskeletal injury treated by athletic trainers, often affecting activities of daily living and delaying return to play. Most of these cases present with pain and swelling in the ankle, resulting in decreased range of motion and strength deficits. Due to these impairments, proper treatment is necessary to avoid additional loss of play and prevent future injuries. Recently, there has been an increased use of deep oscillation therapy by clinicians to manage pain and swelling following a variety of injuries, including ankle sprains. However, very little evidence has been produced regarding the clinical effectiveness of deep oscillation therapy, limiting its application in therapeutic rehabilitation of acute lateral ankle sprains. Clinical Question: Is deep oscillation therapy effective in reducing pain and swelling in patients with acute lateral ankle sprains compared with the current standard of care protection, rest, ice, compression, and elevation? Summary of Key Findings: The literature was searched for studies of level 2 evidence or higher that investigated deep oscillation therapy on pain and inflammation in patients with lateral ankle sprains. Three randomized control trials were located and appraised. One of the 3 studies demonstrate a reduction in pain following 6 weeks of deep oscillation therapy compared with the standard of care or placebo interventions. The 2 other studies, 1 utilizing a 5-day treatment and the other a 1 time immediate application, found no differences in deep oscillation therapy compared with the standard of care. Clinical Bottom Line: There is inconclusive evidence to support the therapeutic use of deep oscillation therapy in reducing pain and swelling in patients with acute lateral ankle sprains above and beyond the current standard of care. In addition, the method of treatment application and parameters used may influence the effectiveness of deep oscillation therapy. Strength of Recommendation: Level B.
Matt Hausmann, Jacob Ober, and Adam S. Lepley
Justin L. Rush, Lindsey K. Lepley, Steven Davi, and Adam S. Lepley
Context: Altered quadriceps activation is common following anterior cruciate ligament reconstruction (ACLR), and can persist for years after surgery. These neural deficits are due, in part, to chronic central nervous system alterations. Transcranial direct current stimulation (tDCS) is a noninvasive modality, that is, believed to immediately increase motor neuron activity by stimulating the primary motor cortex, making it a promising modality to use improve outcomes in the ACLR population. Objective: To determine if a single treatment of tDCS would result in increased quadriceps activity and decreased levels of self-reported pain and dysfunction during exercise. Design: Randomized crossover design. Setting: Controlled laboratory. Patients: Ten participants with a history of ACLR (5 males/5 females, 22.9 [4.23] y, 176.57 [12.01] cm, 80.87 [16.86] kg, 68.1 [39.37] mo since ACLR). Interventions: Active tDCS and Sham tDCS. Main Outcome Measures: Percentage of maximum electromyographic data of vastus medialis and lateralis, voluntary isometric strength, percentage of voluntary activation, and self-reported pain and symptom scores were measured. The 2 × 2 repeated-measures analysis of variance by limb were performed to explain the differences between time points (pre and post) and condition (tDCS and sham). Results: There was a significant time main effect for quadriceps percentage of maximum electromyographic of vastus medialis (F 9,1 = 11.931, P = .01) and vastus lateralis (F 9,1 = 9.132, P = .01), isometric strength (F 9,1 = 5.343, P = .046), and subjective scores for pain (F 9,1 = 15.499, P = .04) and symptoms (F 9,1 = 15.499, P = .04). Quadriceps percentage of maximum electromyographic, isometric strength, and voluntary activation showed an immediate decline from pre to post regardless of tDCS condition. Subjective scores improved slightly after each condition. Conclusions: One session of active tDCS did not have an immediate effect on quadriceps activity and subjective scores of pain and symptoms. To determine if tDCS is a valid modality for this patient population, a larger scale investigation with multiple treatments of active tDCS is warranted.
Steven M. Davi, Colleen K. Woxholdt, Justin L. Rush, Adam S. Lepley, and Lindsey K. Lepley
Context: Traditionally, quadriceps activation failure after anterior cruciate ligament reconstruction (ACLR) is estimated using discrete isometric torque values, providing only a snapshot of neuromuscular function. Sample entropy (SampEn) is a mathematical technique that can measure neurologic complexity during the entirety of contraction, elucidating qualities of neuromuscular control not previously captured. Objective: To apply SampEn analyses to quadriceps electromyographic activity in order to more comprehensively characterize neuromuscular deficits after ACLR. Design: Cross-sectional. Setting: Laboratory. Participants: ACLR: n = 18; controls: n = 24. Interventions: All participants underwent synchronized unilateral quadriceps isometric strength, activation, and electromyography testing during a superimposed electrical stimulus. Main Outcome Measures: Group differences in strength, activation, and SampEn were evaluated with t tests. Associations between SampEn and quadriceps function were evaluated with Pearson product–moment correlations and hierarchical linear regressions. Results: Vastus medialis SampEn was significantly reduced after ACLR compared with controls (P = .032). Vastus medialis and vastus lateralis SampEn predicted significant variance in activation after ACLR (r 2 = .444; P = .003). Conclusions: Loss of neurologic complexity correlates with worse activation after ACLR, particularly in the vastus medialis. Electromyographic SampEn is capable of detecting underlying patterns of variability that are associated with the loss of complexity between key neurophysiologic events after ACLR.
Julie P. Burland, Adam S. Lepley, Marc Cormier, Lindsay J. DiStefano, and Lindsey K. Lepley
Context: Altered neural signaling is known to have a direct impact on psychological wellness. Therefore, disruptions in neural signaling after anterior cruciate ligament reconstruction may influence psychological dysfunction, in some cases manifesting as learned helplessness. Helplessness is a psychological paradigm that presents as altered neuromuscular control, reduced motivation, and psychological deficits. Objectives: The authors sought to evaluate the relationship between helplessness, neural activity, and quadriceps function at different time points after anterior cruciate ligament reconstruction. Evidence Acquisition: Twenty-nine individuals with unilateral anterior cruciate ligament reconstruction were categorized into early group (<2 y, age: 19.13 [2.18] y; height: 1.77 [0.11] m; mass: 76.903 [11.87] kg) or late group (>2 y, age: 22  y; height: 1.67 [0.07] m; mass: 65.66 [11.33] kg). Quadriceps function (activation and strength), spinal-reflexive and corticospinal excitability (active motor thresholds and motor evoked potentials), and helplessness were obtained. A principal component analysis was performed by group (early and late) to identify which factors of helplessness were most associated with neural activity and quadriceps function. Pearson product moment correlation analyses were performed by group to determine associations between individual components and main outcomes. Evidence Synthesis: In the early group, cognitive readiness was associated with quadriceps strength of the injured limb (r 2 = .513, P = .004), and self-awareness/management was associated with motor threshold of the injured limb (r 2 = .238, P = .05). In the late group, intrinsic helplessness was associated with motor output of injured limb (r 2 = .653, P = .01). Conclusion: Helplessness is made up of several attributional constructs, which are altered at different phases of recovery. Helplessness constructs interact differently with neural activity and quadriceps function across time. These findings are preliminary and do not establish a causal link between neural alterations and learned helplessness. Future studies should serially evaluate both changes in neural activity and learned helplessness attributes throughout recovery.
Brian G. Pietrosimone, Adam S. Lepley, Hayley M. Ericksen, Phillip A. Gribble, and Jason Levine
Disability is common in a proportion of patients after anterior cruciate ligament reconstruction (ACL-R). Neuromuscular quadriceps deficits are a hallmark impairment after ACL-R, yet the link between muscle function and disability is not understood.
To evaluate the ability of quadriceps strength and cortical excitability to predict self-reported disability in patients with ACL-R.
Fifteen participants with a history of ACL-R (11 female, 4 male; 172 ± 9.8 cm, 70.4 ± 17.5 kg, 54.4 ± 40.9 mo postsurgery) were included in this study. Corticospinal excitability was assessed using active motor thresholds (AMT), while strength was assessed with maximal voluntary isometric contractions (MVIC). Both voluntary strength and corticospinal excitability were used to predict disability measured with the International Knee Documentation Committee Index (IKDC).
The overall multiple-regression model significantly predicted 66% of the variance in self-reported disability as measured by the IKDC index (R 2 = .66, P = .01). Initial imputation of MVIC into the model accounted for 61% (R 2 = .61, P = .01) of the variance in IKDC. The subsequent addition of AMT into the model accounted for an insignificant increase of 5% (Δ R 2 = .05, P = .19) in the prediction capability of the model.
Quadriceps voluntary strength and cortical excitability predicted two-thirds of the variance in disability of patients with ACL-R, with strength accounting for virtually all of the predictive capability of the model.
Conrad M. Gabler, Adam S. Lepley, Tim L. Uhl, and Carl G. Mattacola
Proper neuromuscular activation of the quadriceps muscle is essential for maintaining quadriceps (quad) strength and lower-extremity function. Quad activation (QA) failure is a common characteristic observed in patients with knee pathologies, defined as an inability to voluntarily activate the entire alpha-motor-neuron pool innervating the quad. One of the more popular techniques used to assess QA is the superimposed burst (SIB) technique, a force-based technique that uses a supramaximal, percutaneous electrical stimulation to activate all of the motor units in the quad during a maximal, voluntary isometric contraction. Central activation ratio (CAR) is the formula used to calculate QA level (CAR = voluntary force/SIB force) with the SIB technique. People who can voluntarily activate 95% or more (CAR = 0.95–1.0) of their motor units are defined as being fully activated. Therapeutic exercises aimed at improving quad strength in patients with knee pathologies are limited in their effectiveness due to a failure to fully activate the muscle. Within the past decade, several disinhibitory interventions have been introduced to treat QA failure in patients with knee pathologies. Transcutaneous electrical nerve stimulation (TENS) and cryotherapy are sensory-targeted modalities traditionally used to treat pain, but they have been shown to be 2 of the most successful treatments for increasing QA levels in patients with QA failure. Both modalities are hypothesized to positively affect voluntary QA by disinhibiting the motor-neuron pool of the quad. In essence, these modalities provide excitatory afferent stimuli to the spinal cord, which thereby overrides the inhibitory afferent signaling that arises from the involved joint. However, it remains unknown whether 1 is more effective than the other for restoring QA levels in patients with knee pathologies. By knowing the capabilities of each disinhibitory modality, clinicians can tailor treatments based on the rehabilitation goals of their patients.
Focused Clinical Question:
Is TENS or cryotherapy the more effective disinhibitory modality for treating QA failure (quantified via CAR) in patients with knee pathologies?
Susan Sullivan Glenney, Derrick Paul Brockemer, Andy C. Ng, Michael A. Smolewski, Vladimir M. Smolgovskiy, and Adam S. Lepley
Background: Studies have demonstrated beneficial effects of exercise on cardiovascular disease biomarkers for healthy individuals; however, a comprehensive review regarding the effect of exercise on cardiovascular disease biomarkers in at-risk populations is lacking. Methods: A literature search was performed to identify studies meeting the following criteria: randomized controlled study, participants with pathology/activity limitations, biomarker outcome (total cholesterol, high-density lipoprotein, low-density lipoprotein, C-reactive protein, insulin, triglycerides, or glucose), and exercise intervention. Means and standard deviations from each biomarker were used to calculate standardized Cohen’s d effect sizes with 95% confidence intervals. Results: In total, 37 articles were included. The majority (44/57; 77%) of data points demonstrated moderate to strong effects for the reduction in total cholesterol, triglycerides, and low-density lipoprotein, and elevation in high-density lipoprotein following exercise. The majority of data points demonstrated strong effects for reductions in blood glucose (24/30; 80%) and insulin (23/24; 96%) levels following exercise intervention. Conclusion: Evidence is heterogeneous regarding the influence of exercise on cardiovascular disease biomarkers in at-risk patients, which does not allow a definitive conclusion. Favorable effects include reductions in triglycerides, total cholesterol, low-density lipoprotein, glucose, and insulin, and elevation in high-density lipoprotein following exercise intervention. The strongest evidence indicates that exercise is favorable for the reduction in glucose and cholesterol levels among obese patients, and reduction of insulin regardless of population.
Brittney A. Luc, Adam S. Lepley, Michael A. Tevald, Phillip A. Gribble, Donald B. White, and Brian G. Pietrosimone
Alterations in corticomotor excitability are observed in a variety of patient populations, including the musculature surrounding the knee and ankle after joint injury. Active motor threshold (AMT) and motor-evoked-potential (MEP) amplitudes elicited through transcranial magnetic stimulation (TMS) are outcome measures used to assess corticomotor excitability and have been deemed reliable in upper-extremity musculature. However, there are few studies assessing the reliability of TMS measures in lower-extremity musculature.
To determine the intersession reliability of AMT and MEP amplitudes over 14 and 28 d in the quadriceps and fibularis longus (FL).
Descriptive laboratory study.
20 able-bodied volunteers (10 men, 10 women; 22.35 ± 2.3 y, 1.71 ± 0.11 m, 73.61 ± 16.77 kg).
Main Outcome Measures:
AMT and MEP amplitudes were evaluated at 95%, 100%, 105%, 110%, 120%, 130%, and 140% of AMT in the dominant and nondominant quadriceps and FL. Interclass correlation coefficients (ICCs) were used to assess reliability for absolute agreement and internal consistency between baseline and 2 follow-up sessions at 14 and 28 d postbaseline. Each ICC was fit with the best-fit straight line or parabola to smooth out noise in the observations and best determine if a pattern existed in determining the most reliable MEP value.
All muscles yielded strong ICCs between baseline and both time points for AMT. MEPs in both the quadriceps and FL produced varying degrees of reliability, with the greatest reliability demonstrated on day 28 at 130% and 140% of AMT in the quadriceps and FL, respectively. The dominant FL muscle showed a significant pattern; as TMS intensity increased, MEP reliability increased.
TMS can be used to reliably identify corticomotor alterations after therapeutic interventions, as well as monitor disease progression.
Adam S. Lepley, Allison M. Strouse, Hayley M. Ericksen, Kate R. Pfile, Phillip A. Gribble, and Brian G. Pietrosimone
Components of gluteal neuromuscular function, such as strength and corticospinal excitability, could potentially influence alterations in lower extremity biomechanics during jump landing.
To determine the relationship between gluteal muscle strength, gluteal corticospinal excitability, and jump-landing biomechanics in healthy women.
Descriptive laboratory study.
37 healthy women (21.08 ± 2.15 y, 164.8 ± 5.9 cm, 65.4 ± 12.0 kg).
Bilateral gluteal strength was assessed through maximal voluntary isometric contractions (MVIC) using an isokinetic dynamometer. Strength was tested in the open chain in prone and side-lying positions for the gluteus maximus and gluteus medius muscles, respectively. Transcranial magnetic stimulation was used to elicit measures of corticospinal excitability. Participants then performed 3 trials of jump landing from a 30-cm box to a distance of 50% of their height, with an immediate rebound to a maximal vertical jump. Each jump-landing trial was video recorded (2-D) and later scored for errors.
Main Outcome Measures:
MVICs normalized to body mass were used to assess strength in the gluteal muscles of the dominant and nondominant limbs. Corticospinal excitability was assessed by means of active motor threshold (AMT) and motor-evoked potentials (MEP) elicited at 120% of AMT. The Landing Error Scoring System (LESS) was used to evaluate jump-landing biomechanics.
A moderate, positive correlation was found between dominant gluteus maximus MEP and LESS scores (r = .562, P = .029). No other significant correlations were observed for MVIC, AMT, or MEP for the gluteus maximus and gluteus medius, regardless of limb.
The findings suggest a moderate relationship between dominant gluteus maximus corticospinal excitability and a clinical measure of jump-landing biomechanics. Further research is required to substantiate the findings and expand our understanding of the central nervous system’s role in athletic movement.