Physically Active Adults with Low Back Pain do not Demonstrate Altered Deadlift Mechanics: A Novel Application of Myotonometry to Estimate Inter-Muscular Load Sharing.

Background: Rehabilitation clinicians that work with physically active populations are challenged with how to safely return patients back to performing deadlift movements following low back injury. Application of reliable and valid tests and measures to quantify impairments related to low back pain (LBP) enhances clinical decision making and may affect outcomes. Myotonometry is a non-invasive method to assess muscle stiffness which has demonstrated significant associations with physical performance and musculoskeletal injury. Hypothesis/Purpose: The purpose of this study was to compare the stiffness of trunk (lumbar multifidus [LM] and longissimus thoracis [LT]) and lower extremity (vastus lateralis [VL] and biceps femoris [BF]) muscles between individuals with and without LBP during the lying, standing, and deadlifting body positions. Study Design: Cross-sectional cohort comparison. Methods: Muscle stiffness measures were collected in the VL, BF, LM, and LT muscles with participants in lying (supine and prone), standing, and the trap bar deadlift position. Separate analyses of covariance were conducted to compare absolute and relative muscle stiffness between the groups for each muscle and condition. Results: Sixty-eight participants (41 female, 21.3 years, 34 LBP) volunteered for the study. Within the deadlift condition there was a significantly greater increase in the percent-muscle stiffness change in the VL (p = .029, 21.9%) and BF (p = .024, 11.2%) muscles in the control group than in the LBP group. There were no differences in percent-muscle stiffness changes for the standing condition nor were there any absolute muscle stiffness differences between the two groups for the three conditions. Conclusion: No differences in muscle stiffness were identified in the lying, standing, or deadlifting conditions between participants with and without LBP. Differences in percent stiffness changes were noted between groups for the deadlift position, however the differences were modest and within measurement error. Future studies should investigate the utility of myotonometry as a method to identify LBP-related impairments that contribute to chronic and/or recurrent low back injury. Level of Evidence: Level 3.

Myotonometry is Capable of Reliably Obtaining Trunk and Thigh Muscle Stiffness Measures in Military Cadets During Standing and Squatting Postures.

INTRODUCTION: Low back and lower extremity injuries are responsible for the highest percentage of musculoskeletal injuries in U.S. Army soldiers. Execution of common soldier tasks as well as army combat fitness test events such as the three-repetition maximum deadlift depends on healthy functioning trunk and lower extremity musculature to minimize the risk of injury. To assist with appropriate return to duty decisions following an injury, reliable and valid tests and measures must be applied by military health care providers. Myotonometry is a noninvasive method to assess muscle stiffness, which has demonstrated significant associations with physical performance and musculoskeletal injury. The aim of this study is to determine the test-retest reliability of myotonometry in lumbar spine and thigh musculature across postures (standing and squatting) that are relevant to common soldier tasks and the maximum deadlift. MATERIALS AND METHODS: Repeat muscle stiffness measures were collected in 30 Baylor University Army Cadets with 1 week between each measurement. Measures were collected in the vastus lateralis (VL), biceps femoris (BF), lumbar multifidus (LM), and longissimus thoracis (LT) muscles with participants in standing and squatting positions. Intraclass correlation coefficients (ICCs3,2) were estimated, and their 95% CIs were calculated based on a mean rating, mixed-effects model. RESULTS: The test-retest reliability (ICC3,2) of the stiffness measures was good to excellent in all muscles across the standing position (ICCs: VL = 0.94 [0.87-0.97], BF = 0.97 [0.93-0.98], LM = 0.96 [0.91-0.98], LT = 0.81 [0.59-0.91]) and was excellent in all muscles across the squatting position (ICCs: VL = 0.95 [0.89-0.98], BF = 0.94 [0.87-0.97], LM = 0.96 [0.92-0.98], LT = 0.93 [0.86-0.97]). CONCLUSION: Myotonometry can reliably acquire stiffness measures in trunk and lower extremity muscles of healthy individuals in standing and squatting postures. These results may expand the research and clinical applications of myotonometry to identify muscular deficits and track intervention effectiveness. Myotonometry should be used in future studies to investigate muscle stiffness in these body positions in populations with musculoskeletal injuries and in research investigating the performance and rehabilitative intervention effectiveness.

The Utility of Myotonometry in Musculoskeletal Rehabilitation and Human Performance Programming.

Myotonometry is a relatively novel method used to quantify the biomechanical and viscoelastic properties (stiffness, compliance, tone, elasticity, creep, and mechanical relaxation) of palpable musculotendinous structures with portable mechanical devices called myotonometers. Myotonometers obtain these measures by recording the magnitude of radial tissue deformation that occurs in response to the amount of force that is perpendicularly applied to the tissue through a device's probe. Myotonometric parameters such as stiffness and compliance have repeatedly demonstrated strong correlations with force production and muscle activation. Paradoxically, individual muscle stiffness measures have been associated with both superior athletic performance and a higher incidence of injury. This indicates optimal stiffness levels may promote athletic performance, whereas too much or too little may lead to an increased risk of injury. Authors of numerous studies suggested that myotonometry may assist practitioners in the development of performance and rehabilitation programs that improve athletic performance, mitigate injury risk, guide therapeutic interventions, and optimize return-to-activity decision-making. Thus, the purpose of our narrative review was to summarize the potential utility of myotonometry as a clinical tool that assists musculoskeletal clinicians with the diagnosis, rehabilitation, and prevention of athletic injuries.

The influence of conventional T2 MRI indices in predicting who will walk outside one year after spinal cord injury.

Context/Objective: Magnetic resonance imaging (MRI) indices of spinal cord damage are predictive of future motor function after spinal cord injury (SCI): hyperintensity length, midsagittal tissue bridges, and Brain and Spinal Injury Center (BASIC) scores. Whether these indices are predictive of outdoor walking after SCI is unknown. The primary purpose was to see if these MRI indices predict the ability to walk outdoors one-year after SCI. The secondary purpose was to determine if MRI indices provide additional predictive value if initial lower extremity motor scores are available.Design: Retrospective. Clinical T2-weighted MRIs were used to quantify spinal cord damage. Three MRI indices were calculated: midsagittal ventral tissue bridges, hyperintensity length, BASIC scores.Setting: Academic hospital.Participants: 129 participants with cervical SCI.Interventions: Inpatient rehabilitation.Outcomes Measures: One year after SCI, participants self-reported their outdoor walking ability.Results: Midsagittal ventral tissue bridges, hyperintensity length, and BASIC scores significantly correlated with outdoor walking ability (R = 0.34, P < 0.001; R = -0.25, P < 0.01; Rs = -0.35, P < 001, respectively). Using midsagittal ventral tissue bridges and hyperintensity length, the final adjusted R2 for model 1 = 0.19. For model 2, the adjusted R2 using motor scores alone = 0.81 and MRI variables were non-significant. All five participants with observable intramedullary hemorrhage reported they were unable to walk one block outdoors.Conclusions: The MRI indices were significant predictors of outdoor walking ability, but when motor scores were available, this was the strongest predictor and neither midsagittal tissue bridges nor hyperintensity length contributed additional value. MRI indices may be a quick and convenient supplement to physical examination when motor testing is unavailable.

The Utility of Myotonometry in Musculoskeletal Rehabilitation and Human Performance Programming.

Myotonometry is a relatively novel method used to quantify the biomechanical and viscoelastic properties (stiffness, compliance, tone, elasticity, creep, mechanical relaxation) of palpable musculotendinous structures with portable mechanical devices called myotonometers. Myotonometers obtain these measures by recording the magnitude of radial tissue deformation that occurs in response to the amount of force that is perpendicularly applied to the tissue through a device's probe. Myotonometric parameters such as stiffness and compliance have repeatedly demonstrated strong correlations with force production and muscle activation. Paradoxically, individual muscle stiffness measures have been associated with both superior athletic performance and higher incidence of injury. This suggest there may be optimal stiffness levels that promotes athletic performance while too much or too little may lead to an increased risk of injury. Numerous studies suggest that myotonometry may assist practitioners in the development of performance and rehabilitation programs that improves athletic performance, mitigates injury risk, guides therapeutic interventions, and optimizes return to activity decision making. Thus, the purpose of this narrative review is to summarize the potential utility of myotonometry as a clinical tool that assists musculoskeletal clinicians with the diagnosis, rehabilitation, and prevention of athletic injuries.

Spinal Cord Tissue Bridges Validation Study: Predictive Relationships With Sensory Scores Following Cervical Spinal Cord Injury.

Background: Using magnetic resonance imaging (MRI), widths of ventral tissue bridges demonstrated significant predictive relationships with future pinprick sensory scores, and widths of dorsal tissue bridges demonstrated significant predictive relationships with future light touch sensory scores, following spinal cord injury (SCI). These studies involved smaller participant numbers, and external validation of their findings is warranted. Objectives: The purpose of this study was to validate these previous findings using a larger independent data set. Methods: Widths of ventral and dorsal tissue bridges were quantified using MRI in persons post cervical level SCI (average 3.7 weeks post injury), and pinprick and light touch sensory scores were acquired at discharge from inpatient rehabilitation (average 14.3 weeks post injury). Pearson product-moments were calculated and linear regression models were created from these data. Results: Wider ventral tissue bridges were significantly correlated with pinprick scores (r = 0.31, p < 0.001, N = 136) and wider dorsal tissue bridges were significantly correlated with light touch scores (r = 0.31, p < 0.001, N = 136) at discharge from inpatient rehabilitation. Conclusion: This retrospective study's results provide external validation of previous findings, using a larger sample size. Following SCI, ventral tissue bridges hold significant predictive relationships with future pinprick sensory scores and dorsal tissue bridges hold significant predictive relationships with future light touch sensory scores.

Lateral Corticospinal Tract and Dorsal Column Damage: Predictive Relationships With Motor and Sensory Scores at Discharge From Acute Rehabilitation After Spinal Cord Injury.

OBJECTIVE: To determine if lateral corticospinal tract (LCST) integrity demonstrates a significant predictive relationship with future ipsilateral lower extremity motor function (LEMS) and if dorsal column (DC) integrity demonstrates a significant predictive relationship with future light touch (LT) sensory function post spinal cord injury (SCI) at time of discharge from inpatient rehabilitation. DESIGN: Retrospective analyses of imaging and clinical outcomes. SETTING: University and academic hospital. PARTICIPANTS: A total of 151 participants (N=151) with SCI. INTERVENTIONS: Inpatient rehabilitation. MAIN OUTCOME MEASURES: LEMS and LT scores at discharge from inpatient rehabilitation. RESULTS: In 151 participants, right LCST spared tissue demonstrated a significant predictive relationship with right LEMS percentage recovered (ß=0.56; 95% confidence interval [CI], 0.37-0.73; R=0.43; P<.001). Left LCST spared tissue demonstrated a significant predictive relationship with left LEMS percentage recovered (ß=0.66; 95% CI, 0.50-0.82; R=0.51; P<.001). DC spared tissue demonstrated a significant predictive relationship with LT percentage recovered (ß=0.69; 95% CI, 0.52-0.87; R=0.55; P<.001). When subgrouping the participants into motor complete vs incomplete SCI, motor relationships were no longer significant, but the sensory relationship remained significant. Those who had no voluntary motor function but recovered some also had significantly greater LCST spared tissue than those who did not recover motor function. CONCLUSIONS: LCST demonstrated significant moderate predictive relationships with lower extremity motor function at the time of discharge from inpatient rehabilitation, in an ipsilesional manner. DC integrity demonstrated a significant moderate predictive relationship with recovered function of LT. With further development, these neuroimaging methods might be used to predict potential deficits after SCI and to provide corresponding targeted interventions.

Ultrasonographic Validation for Needle Placement in the Tibialis Posterior Muscle.

BACKGROUND: The tibialis posterior (TP) muscle plays an important role in normal foot function. Safe, efficacious therapeutic approaches addressing this muscle are necessary; however, the location of the muscle in the deep posterior compartment can create challenges. PURPOSE: The purpose of this study was to assess the accuracy of needle placement in the TP muscle and determine the needle placement in relation to the neurovascular structures located within the deep compartment. DESIGN: Cross Sectional Study. METHODS: Needle placement and ultrasound imaging were performed on 20 healthy individuals. A 50 mm or 60 mm needle was inserted between 30 - 50% of the tibial length measured from the medial tibiofemoral joint. The needle was inserted in a medial to lateral direction into the right extremity with the patient in right side lying. Placement of the needle into the TP muscle was verified with ultrasound imaging, and the shortest distance from the needle to the posterior tibial artery and tibial nerve was measured. The depth from the skin to the superficial border of the TP muscle was also measured. RESULTS: Ultrasonography confirmed the needle filament was inserted into the TP muscle in all 20 individuals and did not penetrate the neurovascular bundle in any individual. The mean distance from the needle to the tibial nerve and posterior tibial artery was 10.0 + 4.7 mm and 10.2 + 4.7 mm respectively. The superficial border of the TP muscle from the skin was at a mean depth of 25.8 + 4.9 mm. CONCLUSION: This ultrasound imaging needle placement study supports placement of a solid filament needle into the TP muscle with avoidance of the neurovascular structures of the deep posterior compartment when placed from a medial to lateral direction at 30-50% of the tibial length. LEVEL OF EVIDENCE: 2b.

Normative Parameters of Gastrocnemius Muscle Stiffness and Associations with Patient Characteristics and Function.

BACKGROUND: Quantifying muscle stiffness may aid in the diagnosis and management of individuals with muscle pathology. Therefore, the primary purpose of this study was to establish normative parameters and variance estimates of muscle stiffness in the gastrocnemius muscle in a resting and contracted state. A secondary aim was to identify demographic, anthropometric, medical history factors, and biomechanical factors related to muscle stiffness. METHODS: Stiffness of the gastrocnemius muscle was measured in both a resting and contracted state in 102 asymptomatic individuals in this cross-sectional study. Differences based on muscle state (resting vs contracted) and sex (female vs male) were assessed using a 2 X 2 analysis of variance (ANOVA). Associations between muscle stiffness and sex, age, BMI, race, exercise frequency, exercise duration, force production, and step length were assessed using correlation analysis. RESULTS: Gastrocnemius muscle stiffness significantly increased from a resting to a contracted state [mean difference: 217.5 (95% CI: 191.3, 243.8), p < 0.001]. In addition, muscles stiffness was 35% greater for males than females in a resting state and 76% greater in a contracted state. Greater muscle stiffness in a relaxed and contracted state was associated with larger plantarflexion force production (r = .26, p < 0.01 and r = .23, p < 0.01 respectively). CONCLUSION: Identifying normative parameters and variance estimates of muscle stiffness in asymptomatic individuals may help guide diagnosing and managing individuals with aberrant muscle function. LEVEL OF EVIDENCE: 2b Individual Cohort Study. CLINICAL RELEVANCE: What is known about the subject: Muscle stiffness has been shown to be related to individuals with pathology such as Achilles tendinopathy; however, research is sparse regarding normative values of muscle stiffness. Measuring muscle stiffness may also be a way to potentially predict individuals prone to injury or to monitor the effectiveness of management strategies.What this study adds to existing knowledge: This study establishes defined estimates of muscle stiffness of the gastrocnemius in both a relaxed and contracted state in healthy individuals. Myotonometry measures of muscle stiffness demonstrated an increase in stiffness during contraction that varies by sex. Greater gastrocnemius muscle stiffness was associated with increased plantarflexion force production.

Axial MRI biomarkers of spinal cord damage to predict future walking and motor function: a retrospective study.

STUDY DESIGN: Retrospective. OBJECTIVES: Primary: to assess if axial damage ratios are predictors of future walking after spinal cord injury (SCI), and if they add any predictive value if initial neurological impairment grades are available. Secondary: to determine if lateral spinal cord regions are predictors of future lower extremity motor scores (LEMS). SETTING: University/hospital. METHODS: Axial T2-weighted MRIs were used. Axial damage ratios and non-damaged lateral cord volumes were calculated. Each participant answered at 1 year after SCI, "Are you able to walk for 150 feet? (45.72 meters)" For the secondary aim, right and left LEMS were used. RESULTS: In total, 145 participants were selected. Individuals that could walk had smaller ratios than those that were unable. Walking and axial damage ratios were negatively correlated. A 0.374 ratio cut-off showed optimal sensitivity/specificity. When initial neurological grades were used, axial damage ratios did not add predictive value. Forty-two participants had LEMS available and were included for the secondary aim. Right cord regions and right LEMS were positively correlated and left regions and left LEMS, but these variables were also correlated with each other. CONCLUSIONS: Axial damage ratios were significant predictors of walking ability 1 year after SCI. However, this measure did not add predictive value over initial neurological grades. Lateral cord regions correlated with same-side LEMS, but the opposite was also found, calling this biomarker's specificity into question. Axial damage ratios may be useful in predicting walking after SCI if initial neurological grades are unavailable. SPONSORSHIP: This research was funded by a National Institutes of Health award, National Institute of Child Health and Development-NIH R03HD094577.

A Comparison of Clinical Spinal Mobility Measures to Experimentally Derived Lumbar Spine Passive Stiffness.

Spinal stiffness and mobility assessments vary between clinical and research settings, potentially hindering the understanding and treatment of low back pain. A total of 71 healthy participants were evaluated using 2 clinical assessments (posteroanterior spring and passive intervertebral motion) and 2 quantitative measures: lumped mechanical stiffness of the lumbar spine and local tissue stiffness (lumbar erector spinae and supraspinous ligament) measured via myotonometry. The authors hypothesized that clinical, mechanical, and local tissue measures would be correlated, that clinical tests would not alter mechanical stiffness, and that males would demonstrate greater lumbar stiffness than females. Clinical, lumped mechanical, and tissue stiffness were not correlated; however, gradings from the posteroanterior spring and passive intervertebral motion tests were positively correlated with each other. Clinical assessments had no effect on lumped mechanical stiffness. The males had greater lumped mechanical and lumbar erector spinae stiffness compared with the females. The lack of correlation between clinical, tissue, and lumped mechanical measures of spinal stiffness indicates that the use of the term "stiffness" by clinicians may require reevaluation; clinicians should be confident that they are not altering mechanical stiffness of the spine through segmental mobility assessments; and greater resting lumbar erector stiffness in males suggests that sex should be considered in the assessment and treatment of the low back.

Confirming the geography of fatty infiltration in the deep cervical extensor muscles in whiplash recovery.

Previous preliminary work mapped the distribution of neck muscle fat infiltration (MFI) in the deep cervical extensor muscles (multifidus and semispinalis cervicis) in a small cohort of participants with chronic whiplash associated disorders (WAD), recovered, and healthy controls. While MFI was reported to be concentrated in the medial portion of the muscles in all participants, the magnitude was significantly greater in those with chronic WAD. This study aims to confirm these results in a prospective fashion with a larger cohort and compare the findings across a population of patients with varying levels of WAD-related disability one-year following the motor vehicle collision. Sixty-one participants enrolled in a longitudinal study: Recovered (n = 25), Mild (n = 26) and Severe WAD (n = 10) were studied using Fat/Water magnetic resonance imaging, 12-months post injury. Bilateral measures of MFI in four quartiles (Q1-Q4; medial to lateral) at cervical levels C4 through C7 were included. A linear mixed model was performed, controlling for covariates (age, sex, body mass index), examining interaction effects, and comparing MFI distribution between groups. The recovered group had significantly less MFI in Q1 compared to the two symptomatic groups. Group differences were not found in the more lateral quartiles. Results at 12 months are consistent with the preliminary study, indicating that MFI is spatially concentrated in the medial portions of the deep cervical extensors regardless of WAD recovery, but the magnitude of MFI in the medial portions of the muscles is significantly larger in those with severe chronic WAD.

Muscle fat infiltration following whiplash: A computed tomography and magnetic resonance imaging comparison.

Here we present a secondary analysis from a parent database of 97 acutely injured participants enrolled in a prospective inception cohort study of whiplash recovery after motor vehicle collision (MVC). The purpose was to investigate the deep and superficial neck extensor muscles with peri-traumatic computed tomography (CT) and longitudinal measures of magnetic resonance imaging (MRI) in participants with varying levels of whiplash-related disability. Thirty-six underwent standard care imaging of the cervical spine with CT at a level-1 trauma designated emergency department. All 36 participants were assessed with MRI of the cervical spine at <1-week, 2-weeks, 3-, and 12-months post-injury and classified into three groups using initial pain severity and percentage scores on the Neck Disability Index (recovered (NDI of 0-8%), mild (NDI of 10-28%), or severe (NDI ≥ 30%)) at 3-months post MVC. CT muscle attenuation values were significantly correlated to muscle fat infiltration (MFI) on MRI at one-week post MVC. There was no significant difference in muscle attenuation across groups at the time of enrollment. A trend of lower muscle attenuation in the deep compared to the superficial extensors was observed in the severe group. MFI values in the deep muscles on MRI were significantly higher in the severe group when compared to the mild group at 1-year post MVC. This study provides further evidence that the magnitude of 1) deep MFI appears unique to those at risk of and eventually transitioning to chronic WAD and that 2) pre- or peri-traumatic muscular health, determined by CT muscle attenuation, may be contribute to our understanding of long-term recovery.

Cost-Effectiveness of Operative Versus Nonoperative Management of Patients With Intra-articular Calcaneal Fractures.

OBJECTIVE: To assess the costs, health gains, and cost-effectiveness of operative versus nonoperative treatment of calcaneal fractures over a 5-year time horizon from both US societal and payer perspectives. METHODS: The societal perspective analysis included both direct medical costs and costs for missed work, whereas the health care payer perspective analysis included only direct medical costs associated with treatment and complications. A decision tree simulation model was developed to estimate the direct medical and indirect costs (2018 US$) and quality-adjusted life-years (QALYs) for treatment of patients sustaining intra-articular calcaneal fractures fixed with an extensile lateral approach. Direct medical costs were obtained from a large US health care system in Utah, Intermountain Healthcare, and indirect costs from the literature. Utility and probability parameters were also derived from the literature. Parameter uncertainty was explored using both one-way and probabilistic sensitivity analysis. RESULTS: From a US societal perspective, operative treatment costs less ($35,110 vs. $39,870) and yielded more QALYs (3.89 vs. 3.51) over 5 years compared with nonoperative treatment. At a willingness-to-pay threshold of $50,000 per QALY, operative fixation had an 89% probability of being cost-effective. From a health care payer perspective, operative management remained cost-effective as the incremental cost-effectiveness ratio is below the willingness-to-pay threshold of $50,000/QALY. CONCLUSION: From both US societal and health care payer perspectives, operative treatment of displaced intra-articular calcaneal fractures utilizing an extensile lateral approach is cost-effective at commonly accepted willingness-to-pay thresholds compared with nonoperative treatment over a 5-year time horizon. Patient variability may impact cost-effectiveness and should be explored in future research. LEVEL OF EVIDENCE: Economic Level III. See Instructions for Authors for a complete description of levels of evidence.

Short-term Effects of Manual Therapy in Patients After Surgical Fixation of Ankle and/or Hindfoot Fracture: A Randomized Clinical Trial.

BACKGROUND: Patients with surgical fixation of ankle and/or hindfoot fractures often experience decreased range of motion and loss of function following surgery and postsurgical immobilization, yet there is minimal evidence to guide care for these patients. OBJECTIVES: To assess whether manual therapy may provide short-term improvements in range of motion, muscle stiffness, gait, and balance in patients who undergo operative fixation of an ankle and/or hindfoot fracture. METHODS: In this multisite, double-blind randomized clinical trial, 72 consecutive patients who underwent open reduction internal fixation of an ankle and/or hindfoot fracture and were receiving physical therapy treatment of exercise and gait training were randomized to receive either impairment-based manual therapy (manual therapy group) or a sham manual therapy treatment of light soft tissue mobilization and proximal tibiofibular joint mobilizations (control group). Participants in both groups received 3 treatment sessions over 7 to 10 days, and outcomes were assessed immediately post intervention. Outcomes included ankle joint range of motion, muscle stiffness, gait characteristics, and balance measures. Group-by-time effects were compared using linear mixed modeling. RESULTS: There were no significant differences between the manual therapy and control groups for range of motion, gait, or balance outcomes. There was a significant difference from baseline to the final follow-up in resting gastrocnemius muscle stiffness between the manual therapy and control groups (-47.9 N/m; 95% confidence interval: -86.1, -9.8; P = .01). There was no change in muscle stiffness for the manual therapy group between baseline and final follow-up, whereas muscle stiffness increased in the control group by 6.4%. CONCLUSION: A brief course of manual therapy consisting of 3 treatment sessions over 7 to 10 days did not lead to better short-term improvement than the application of sham manual therapy for most clinical outcomes in patients after ankle and/or hindfoot fracture who were already being treated with exercise and gait training. Our results, however, suggest that manual therapy might decrease aberrant resting muscle stiffness after ankle and/or hindfoot surgical fixation. LEVEL OF EVIDENCE: Therapy, level 2. J Orthop Sports Phys Ther 2019;49(5):310-319. Epub 13 Feb 2019. doi:10.2519/jospt.2019.8864.

The effect of manual therapy on gastrocnemius muscle stiffness in healthy individuals.

STUDY DESIGN: Randomized clinical trial. BACKGROUND: Muscle stiffness is a potential complication after injury and has been shown to be a risk factor for injury in healthy individuals. OBJECTIVES: The primary purpose of this study was to assess the short-term effects of manual therapy (MT) on muscle stiffness of the gastrocnemius in both a relaxed and contracted state. The secondary purpose was to assess the reliability of a novel clinical tool (MyotonPRO) to measure muscle stiffness in the gastrocnemius in both a passive and contracted state. METHODS: Eighty-four consecutive healthy individuals were randomized to receive Manual Therapy (MT group) directed at the right-side ankle and foot or no treatment (CONTROL group). Muscle stiffness of the gastrocnemius was assessed bilaterally in all participants at baseline and then immediately after intervention in a relaxed and contracted state. Group (MT vs. CONTROL) by side (ipsilateral vs. contralateral) by time (pre vs. post) effects were compared through a 3-way interaction utilizing mixed model ANOVA. Reliability of the MyotonPRO was assessed with two-way mixed model intraclass correlation coefficients. RESULTS: There was a significant 3-way interaction for muscle stiffness of the gastrocnemius in a relaxed state (p<0.01), but not contracted state (p=0.54). All conditions had increased resting muscle stiffness from pre to post measures except for the ipsilateral limb of the MT group. There was not a significant interaction for muscle stiffness in a contracted state. Reliability estimates (ICC) for muscle stiffness measures ranged between 0.898 and 0.986. CONCLUSION: The change in muscle stiffness of the gastrocnemius in a relaxed state depended upon whether individuals received MT. Muscle stiffness measures were highly reliable based on single measurements. LEVEL OF EVIDENCE: Therapy, level 2.

Timing of initiating manual therapy and therapeutic exercises in the management of patients after hindfoot fractures: a randomized controlled trial.

STUDY DESIGN: Randomized clinical trial. BACKGROUND: Patients with fractures to the talus and calcaneus report decreased functional outcomes and develop long-term functional limitations. Although physical therapy is typically not initiated until six weeks after fixation, there's little research on the optimal time to initiate a formal physical therapy program. OBJECTIVES: To assess whether initiating physical therapy including range of motion (ROM) and manual therapy two weeks post-operatively (EARLY) vs. six weeks post-operatively (LATE) in patients with fixation for hindfoot fractures results in different clinical outcomes. METHODS: Fifty consecutive participants undergoing operative fixation of a hindfoot fracture were randomized to either EARLY or LATE physical therapy. Outcomes, including the American Orthopedic Foot and Ankle Society Hindfoot Scale (AOFAS), the Lower Extremity Functional Scale (LEFS), active ROM, swelling, and pain, were collected at three and six months and analyzed using linear mixed-modeling to examine change over time. Adverse events were tracked for 12 months after surgery. RESULTS: The EARLY group demonstrated significantly larger improvements for the AOFAS (p = .01) and the LEFS (p = .01) compared to the LATE group. Pairwise comparison of the LEFS favors the EARLY group at 6 months [7.5 (95%CI -.01 to 15.0), p = .05]. There were no differences between the groups with regard to ROM, pain, and swelling. The LATE group incurred increased adverse events in this study. CONCLUSION: Initiating early physical therapy may improve long-term outcomes and mitigate complications in patients after hindfoot fractures. LEVEL OF EVIDENCE: Therapy, level 2b.

Plantar Pressure and Gait Symmetry in Individuals with Fractures versus Tendon Injuries to the Hindfoot.

BACKGROUND: The intent of this study was to determine whether differences in function, walking characteristics, and plantar pressures exist in individuals after operative fixation of an intra-articular calcaneal fracture (HFX) compared with individuals with operative repair of an Achilles tendon rupture (ATR). METHODS: Twenty patients (ten with HFXs and ten with ATRs) were recruited approximately 3.5 months after operative intervention. All of the participants completed the Lower Extremity Functional Scale and had their foot posture assessed using the Foot Posture Index. Walking velocity was assessed using a pressure mat system, and plantar pressures were measured using an in-shoe sensor. In addition to between-group comparisons, the involved foot was compared with the uninvolved foot for each participant. RESULTS: There were no differences in age, height, weight, or number of days since surgery between the two groups. The HFX group had lower Lower Extremity Functional Scale scores, slower walking velocities, and different forefoot loading patterns compared with the ATR group. The involved limb of both groups was less pronated. CONCLUSIONS: The results indicate that individuals with an HFX spend more time on their involved limb and walk slower than those with an ATR. Plantar pressures in the HFX group were higher in the lateral forefoot and lower in the medial forefoot and in the ATR group were symmetrically lower in the forefoot.

A Subset of Serotonergic Neurons Evokes Hunger in Adult Drosophila.

Hunger is a complex motivational state that drives multiple behaviors. The sensation of hunger is caused by an imbalance between energy intake and expenditure. One immediate response to hunger is increased food consumption. Hunger also modulates behaviors related to food seeking such as increased locomotion and enhanced sensory sensitivity in both insects and vertebrates. In addition, hunger can promote the expression of food-associated memory. Although progress is being made, how hunger is represented in the brain and how it coordinates these behavioral responses is not fully understood in any system. Here, we use Drosophila melanogaster to identify neurons encoding hunger. We found a small group of neurons that, when activated, induced a fed fly to eat as though it were starved, suggesting that these neurons are downstream of the metabolic regulation of hunger. Artificially activating these neurons also promotes appetitive memory performance in sated flies, indicating that these neurons are not simply feeding command neurons but likely play a more general role in encoding hunger. We determined that the neurons relevant for the feeding effect are serotonergic and project broadly within the brain, suggesting a possible mechanism for how various responses to hunger are coordinated. These findings extend our understanding of the neural circuitry that drives feeding and enable future exploration of how state influences neural activity within this circuit.

Potential treatments for food allergy.

This article presents an overview of potential treatments of food allergy, with an emphasis on various forms of immunotherapy (including oral immunotherapy, sublingual immunotherapy, epicutaneous immunotherapy, immunotherapy with modified food antigens, and immunotherapy with a recombinant peanut vaccine). Allergen nonspecific treatments, such as Chinese herbal formulas, probiotics/prebiotics, helminths, monoclonal antibodies, and toll-like receptor agonists, are also summarized.