Fit to Play? Health-Related Fitness Levels of Youth Athletes: A Pilot Study.

ABSTRACT: Pfeifer, CE, Sacko, RS, Ortaglia, A, Monsma, EV, Beattie, PF, Goins, J, and Stodden, DF. Fit to play? Health-related fitness levels of youth athletes: A pilot study. J Strength Cond Res 36(1): 245-251, 2022-A recent National Strength and Conditioning Association position statement suggests that many youth are not prepared for the physical demands of sport. The purpose of this study was to compare health-related fitness (HRF) of youth athletes with normative findings from the general population. We recruited 136 athletes (63 male and 73 female athletes) aged 11-19 (16.01 ± 1.35) years and collected HRF (body composition, cardiorespiratory endurance, musculoskeletal strength and endurance). Results were categorized based on FITNESSGRAM® standards and compared with Canadian youth general population normative data. Most male athletes were classified as "needs improvement" for cardiorespiratory and muscular endurance, and body mass index (BMI). Conversely, most female athletes were at or above the "healthy fitness zone" for all measures. Male athletes at both age groups (11-14, 15-19; p < 0.001) and female athletes aged 11-14 (p < 0.05) demonstrated lower cardiorespiratory endurance compared with Canadian general population. Female athletes (both age groups) demonstrated greater muscular strength, and male athletes (age, 15-19 years) demonstrated lower BMI than the Canadian general population. The results are concerning as male athletes demonstrated poorer HRF compared with the general population. Although most female athletes were within healthy ranges, a portion of them were still at risk. Considering the demands sport places on the body, evaluating HRF is paramount for performance and injury prevention but more importantly for overall health. Youth sport and strength coaches should evaluate and aim to enhance HRF, as participation in sport does not guarantee adequate HRF. Promoting long-term athletic development and life-long health should be a priority in youth.

Spinal manipulation does not affect pressure pain thresholds in the absence of neuromodulators: a randomized controlled trial.

BACKGROUND: Measurement of pressure pain threshold (PPT) is a way to determine one of the many potential treatment effects of spinal manipulative therapy. OBJECTIVE: To determine how multiple spinal manipulations administered in a single-session affected PPTs at local and distal sites in asymptomatic individuals. METHODS: Participants were randomly assigned into one of three groups: Group one (n = 18) received a lumbar manipulation followed by a cervical manipulation. Group two (n = 17) received a cervical manipulation followed by a lumbar manipulation. The control group (n = 19) received two bouts of five minutes of rest. At baseline and after each intervention or rest period, each participant's PPTs were obtained using a handheld algometer. The PPTs were tested bilaterally over the lateral epicondyles of the humerus and over the mid-bellies of the upper trapezius, lumbar paraspinal, and the tibialis anterior muscles. This study was registered with ClinicalTrials.gov, and its Identifier is NCT02828501. RESULTS: Repeated-measures ANOVAs and Kruskal-Wallis tests showed no significant within- or between-group differences in PPT. Within-group effect sizes in the changes of PPT ranged from -.48 at the left paraspinal muscles to .24 at the left lateral humeral epicondyle. Statistical power to detect significant differences at α of 0.05 was calculated to be 0.94. CONCLUSIONS: This study suggests that in young adults who do not have current or recent symptoms of spinal pain, multiple within-session treatments of cervical and lumbar spinal manipulation fail to influence PPTs. Changes in PPT that are observed in symptomatic individuals are likely to be primarily influenced by pain-related neuromodulators rather than by an isolated, mechanical effect of spinal manipulation.

Differences among health care settings in utilization and type of physical rehabilitation administered to patients receiving workers' compensation for musculoskeletal disorders.

INTRODUCTION: There is a paucity of data describing the relationship between practice setting and the delivery of physical rehabilitation to injured workers. PURPOSE: To determine differences in the number of visits, the number of treatment units, and the proportion of billing for physical agents over an episode of care between different practice settings' providing physical rehabilitation to patients receiving workers' compensation for a musculoskeletal problem. METHODS: A large administrative database was evaluated retrospectively. Practice settings were classified as physician office, corporate physical therapy clinic, occupational medicine clinic, hospital-based outpatient clinic, or private physical therapy practice. RESULTS: 70,306 subjects (72.7 % male; mean age = 44.6, SD = 11.8 years) were included in this study. Corporate physical therapy clinics had the highest mean values for total visits (13.1, SD = 12.7) and for total units (66.8, SD = 85.5), and the lowest mean values for proportion of physical agents during the episode of care (.22, SD = .18). Occupational medicine clinics had the lowest mean values for total visits (6.8, SD = 7.9) and for total units (30.4, SD = 36.5), and the highest mean value for proportion of physical agents during the episode of care (.41, SD = .22). When controlling for ICD-9-CM codes, body-part treated, surgical status, and geographical region there were small changes in effect size; however, the significance and directionality of differences between practice settings were not changed. CONCLUSIONS: There were significant differences in billing for physical rehabilitation services between practice settings for patients receiving workers' compensation. Corporate physical therapy clinics billed for more total visits and total units over an episode of care than did other practice settings; however they also billed for a lower proportion of physical agents indicating a greater use of those interventions supported by evidence-based guidelines (exercise and manual therapy) compared to other practice settings.

Edith Holmes Met the Challenges to Lead JOSPT to the Next Level.

SYNOPSIS: After 19 years at the helm, we are privileged to honor Ms. Edith Holmes upon her retirement as Executive Director/Publisher of JOSPT. Ms. Holmes set the standard by integrating and communicating effectively with a diverse group of stakeholders. Ms. Holmes is honored for her superb work, inspiration, and commitment to JOSPT. J Orthop Sports Phys Ther 2022;52(4):169. doi:10.2519/jospt.2022.11258.

Task-Based Functional Connectivity and Blood-Oxygen-Level-Dependent Activation During Within-Scanner Performance of Lumbopelvic Motor Tasks: A Functional Magnetic Resonance Imaging Study.

There are a limited number of neuroimaging investigations into motor control of the lumbopelvic musculature. Most investigation examining motor control of the lumbopelvic musculature utilize transcranial magnetic stimulation (TMS) and focus primarily on the motor cortex. This has resulted in a dearth of knowledge as it relates to how other regions of the brain activate during lumbopelvic movement. Additionally, task-based functional connectivity during lumbopelvic movements has not been well elucidated. Therefore, we used functional magnetic resonance imaging (fMRI) to examine brain activation and ROI-to-ROI task-based functional connectivity in 19 healthy individuals (12 female, age 29.8 ± 4.5 years) during the performance of three lumbopelvic movements: modified bilateral bridge, left unilateral bridge, and right unilateral bridge. The whole brain analysis found robust, bilateral activation within the motor regions of the brain during the bilateral bridge task, and contralateral activation of the motor regions during unilateral bridging tasks. Furthermore, the ROI-to-ROI analysis demonstrated significant connectivity of a motor network that included the supplemental motor area, bilateral precentral gyrus, and bilateral cerebellum regardless of the motor task performed. These data suggest that while whole brain activation reveals unique patterns of activation across the three tasks, functional connectivity is very similar. As motor control of the lumbopelvic area is of high interest to those studying low back pain (LBP), this study can provide a comparison for future research into potential connectivity changes that occur in individuals with LBP.

Normalized Isometric Shoulder Strength as a Predictor of Ball Velocity in Youth Baseball Players.

BACKGROUND: Despite increased awareness of factors related to athletic performance and injury prevention, youth and adolescent baseball players continue to report injuries at alarming rates. Upper extremity muscle strength is an integral part of physical assessment and injury prevention in baseball players, however minimal data exists in youth populations. Changes in anthropometric measures, inherent in physically developing athletes, have been shown to impact strength measures, however normalization methodology is rarely reported. PURPOSE: The purposes of this study were to 1) compare the measurement properties of five potential methods for normalizing isometric shoulder strength in a cohort of 9-12 year old male baseball players and 2) examine the relationship between normalized isometric shoulder strength and ball velocity in a cohort of 9-12 year old male baseball players. STUDY DESIGN: Prospective cohort study (n=159). METHODS: Baseline and follow up height, weight and bilateral ulnar length measurements were assessed followed by isometric strength in both the dominant and non-dominant shoulders. Strength measures included scapular plane abduction (scaption), external rotation (ER) at 0°, ER and internal rotation (IR) at 90°. Ball velocity was assessed as a measure of throwing performance. Intraclass correlation coefficients (ICC2,1), standard errors of measurement (SEM) and minimal detectable change (MDC95) were calculated for all strength measures. Repeated measures ANOVA were conducted comparing changes in normalized strength using five separate anthropometric measures: weight, height, body mass index, ulnar length and % of non-dominant shoulder strength. Linear regression models were used to examine the relationships between normalized isometric shoulder strength and ball velocity. Statistical significance was set a priori at α=0.05. RESULTS: Shoulder strength normalized using ulnar length was the only method that demonstrated excellent reliability (ICC2,1 0.98-0.99) and detected significant changes between strength in each of the four measures tested (SEM 0.39-0.69 Nm). Modest but significant correlations were observed between scaption and ball velocity (r2 = 0.27, p < 0.001) and ER at 0° and ball velocity (r2 = 0.23, p < 0.001). CONCLUSION: Ulnar length was the most stable and reliable normalization method for assessing isometric shoulder strength in youth baseball players. In addition, normalized scaption strength was the most significant predictor of ball velocity, followed by ER at 0° strength in this population. LEVEL OF EVIDENCE: Level 2b (etiology).

Development and preliminary validation of the MedRisk instrument to measure patient satisfaction with chiropractic care.

OBJECTIVE: The purpose of this study is to provide preliminary information regarding the factor-structure, group- and individual-level reliability, and criterion-referenced validity of measures obtained from the MedRisk Instrument for Measuring Patient Satisfaction with Chiropractic Care. METHOD: Three hundred twenty-three subjects who had completed a course of chiropractic care responded to questionnaire in which they rated their degree of satisfaction from 1 to 5 (1 = very unsatisfied to 5 = very satisfied) for each of 20 items. Factor structure was assessed using item-correlation and exploratory factor analysis. Group-level reliability for single test administration was assessed by calculating Cronbach α, and individual-level reliability was determined using the standard error of measure. Criterion-referenced validity was investigated by comparing the item scores and mean scores of individual factors to global measures of satisfaction. RESULTS: Individual item scores ranged from 3.98 for "Office location was convenient" to 4.77 for "My chiropractor treats me respectfully." The items that were most highly correlated with overall patient satisfaction were "My chiropractor thoroughly explained the treatment I received" (r = 0.77) and "My chiropractor answered all of my questions" (r = 0.71). Exploratory factor analysis suggested a 2-factor solution: a 5-item "internal" factor and a 6-item "external" factor. The mean scores from these factors were correlated with the 2 global measures ranging from r = 0.68 to r = 0.80. The standard error of measure was 0.20 for the internal factor and 0.17 for the external factor. CONCLUSIONS: Preliminary assessment suggests that a 13-item version of the MedRisk instrument provides psychometrically sound measures to assess patient satisfaction with chiropractic care; however, additional confirmatory validation should be performed.

The immediate reduction in low back pain intensity following lumbar joint mobilization and prone press-ups is associated with increased diffusion of water in the L5-S1 intervertebral disc.

STUDY DESIGN: Single-group, prospective, repeated-measures design. OBJECTIVES: To determine differences in the changes of diffusion of water in the L5-S1 intervertebral disc between subjects with nonspecific low back pain (LBP) who reported an immediate reduction in pain intensity of 2 or greater on an 11-point (0-10) numeric rating scale after a 10-minute session of lumbar joint mobilization, followed by prone press-up exercises, compared to those who did not report an immediate reduction in pain intensity of 2 or greater on the pain scale. BACKGROUND: Combining lumbar joint mobilization and prone press-up exercises is a common intervention for patients with LBP; however, there is conflicting evidence regarding the effectiveness and efficacy of this approach. Increased knowledge of the physiologic effects of the combined use of these treatments, and the relationship to pain reports, can lead to refinement of their clinical application. METHODS: Twenty adults, aged 22 to 54, participated in this study. All subjects reported LBP of at least 2 on an 11-point (0-10) verbally administered numeric rating scale at the time of enrollment in the study and were classified as being candidates for the combination of joint mobilization and prone press-ups. Subjects underwent T2- and diffusion-weighted lumbar magnetic resonance imaging scans before and immediately after receiving a 10-minute session of lumbar pressures in a posterior-to-anterior direction and prone press-up exercises. Subjects who reported a decrease in current pain intensity of 2 or greater immediately following treatment were classified as immediate responders, while the remainder were classified as not-immediate responders. The apparent diffusion coefficient, representing the diffusion of water in the nucleus pulposis, was calculated from the midsagittal diffusion-weighted images. RESULTS: Following treatment, immediate responders (n = 10) had a mean increase in the apparent diffusion coefficient in the middle portion of the L5-S1 intervertebral disc of 4.2% compared to a mean decrease of 1.6% for the not-immediate responders (P<.005). CONCLUSION: In a group of subjects with LBP, who were classified as being candidates for extension-based treatment, the report of an immediate reduction in pain intensity of 2/10 of greater after a treatment of posterior-to-anterior-directed pressures, followed by prone press-up exercises, was associated with an increase in diffusion of water in the nuclear region of the L5-S1 intervertebral disc. Subjects who did not report a pain reduction of at least 2/10 did not have a change in diffusion. J Orthop Sports Phys Ther 2010;40(5):256-264, Epub 12 March 2010. doi:10.2519/jospt.2010.3284.

An interdisciplinary intensive outpatient pain program is associated with improved patient activation and key outcomes.

Aim: To examine the change in the Patient Activation Measure and physical and psychosocial outcome measures in a military interdisciplinary intensive outpatient program for persistent pain. Materials & methods: Pre- and post-intervention measures, which were also stratified by gender and baseline activation, included patient-reported outcomes and physical function assessment, obtained from 2017 to 2018 program database. Results: The majority of the participants were male (70.9%), with an average age of 29.18 years and pain duration of 4.78 years (n = 103). Patient activation, majority of the patient reported outcomes and functional assessments improved in the overall sample with fewer changes in females on the Defense and Veterans Pain Rating Scale. Conclusion: Improvements were noted on the Patient Activation Measure and majority of the other outcome measures suggesting that service members with persistent pain at any level of patient activation or baseline function, may benefit from an intensive outpatient program.

The change in the diffusion of water in normal and degenerative lumbar intervertebral discs following joint mobilization compared to prone lying.

STUDY DESIGN: Prospective, repeated measures obtained under treatment and control conditions. OBJECTIVES: The purposes of this study were to provide preliminary evidence regarding the immediate change in the diffusion of water in the nuclear region of normal and degenerative lumbar intervertebral discs (IVDs) following a single session of lumbar joint mobilization, and to compare these findings to the immediate change in the diffusion of water following a 10-minute session of prone lying. BACKGROUND: There is conflicting evidence regarding the effectiveness and efficacy of lumbar joint mobilization. Increased knowledge of the physiologic effects of lumbar joint mobilization can lead to refinement of its clinical application. METHODS AND MEASURES: A total of 24 people (15 males and 9 females), ranging in age from 22 to 58 years, participated in this study. All subjects had a history of activity-limiting low back pain. Diffusion-weighted magnetic resonance images (DW-MRIs) were obtained immediately before and after a 10-minute session of lumbar joint mobilization. At least 1 month later, a second session was performed in which DW-MRIs were obtained immediately before and after a 10-minute session of prone lying. RESULTS: Following lumbar joint mobilization, a significant increase (P = .002) in the mean values for diffusion of water was observed within degenerative IVDs at L5-S1 (22.2% increase; effect size, 0.97). Degenerative IVDs at L1-2 to L4-5 and normal IVDs at L1-2 to L5-S1 did not demonstrate a change in diffusion following joint mobilization. Prone lying was not associated with a change in diffusion for normal or degenerative IVDs. CONCLUSIONS: The stimulus provided by lumbar joint mobilization may influence the diffusion of water in degenerative IVDs at L5-S1; however, these are preliminary findings and the relationship of these findings to pain and function needs further investigation.

When It Comes to Editor-in-Chief Dr Guy G. Simoneau, Thanks Isn't Enough-It's More About Inspiration.

After 15.5 years of guiding the Journal of Orthopaedic and Sports Physical Therapy (JOSPT) through its amazing progress, Guy G. Simoneau is stepping down as Editor-in-Chief, handing editorial leadership of the Journal to the very talented and able Clare L. Ardern, beginning with the July 2019 issue. In this editorial, we, the JOSPT/Movement Science Media Board of Directors, summarize some of Dr Simoneau's many achievements and humbly express our gratitude and that of the Editorial Board and publishing team for his overwhelming devotion to the JOSPT for nearly 2 decades. Orthop Sports Phys Ther 2019;49(6):363-365. doi:10.2519/jospt.2019.0102.

The effectiveness of interdisciplinary intensive outpatient programs in a population with diverse chronic pain conditions: a systematic review and meta-analysis.

Aim: To explore the overall effectiveness of interdisciplinary intensive outpatient treatment programs in adults with chronic pain. The secondary aim was to examine the effect of the intervention on individual outcome measures including pain intensity, pain catastrophizing, depressive symptoms, quality of life and describe its effect on medication use. Methods: The preferred reporting items for systematic review and meta-analysis protocols reporting guidelines were followed in this systematic review and meta-analysis. Results: A total of 13 peer-reviewed studies were included in analysis: one randomized controlled trial and 12 observational studies. Conclusion: Although interdisciplinary intensive outpatient programs for chronic pain have only been examined in a limited number of studies, trends suggest that participation in these programs may improve physical, emotional, social and mental health as measured by quality of life measures, while decreasing pain intensity, pain catastrophizing and depressive symptoms in a population with diverse diagnoses.

FUNCTIONAL MOVEMENT SCREEN™ in YOUTH SPORT PARTICIPANTS: EVALUATING the PROFICIENCY BARRIER for INJURY.

BACKGROUND & PURPOSE: The number of youth participating in sport increases yearly; however, the evaluation of youths' movement ability and preparedness for sport remains inadequate or neglected. The Functional Movement Screen (FMS™) is an assessment of an individual's movement quality that has been utilized to evaluate risk of injury in collegiate and professional sport; however, there is minimal support regarding the predictive value of the screen in youth sport. The purpose of this study was to evaluate the mean and distribution of FMS™ performance in sport participants age 11-18, and to evaluate the existence of a composite FMS™ score proficiency barrier to predict injury risk. STUDY DESIGN: Prospective cohort study. METHODS: One hundred, thirty-six participants (63 male, 73 female) age 11 to 18 years (16.01 + 1.35) were recruited from local schools and sport organizations. The FMS™ was administered prior to each participant's competitive season and scored by researchers who demonstrated reliability in assessments derived from the screen (κw = 0.70 to 1). Injury data were collected by the participants' Athletic Trainer over one season. An injury was defined as any physical insult or harm resulting from sports participation that required an evaluation from a health professional with time modified or time lost from sport participation. RESULTS: Females scored significantly higher than males for mean FMS™ composite score (t = 14.40; m = 12.62; p < 0.001), and on individual measures including: the hurdle step (t = 1.91; m = 1.65; p < 0.001), shoulder mobility (t = 2.68; m = 2.02; p < 0.001), active straight leg raise (t = 2.32; m = 1.87; p < 0.001), and the rotary stability components (t = 1.91; m = 1.65; p < 0.05). Two FMS™ composite scores (score < 14 and <15) significantly increased the odds of injury (OR = 2.955). When adjusting for sport, there was no score relating to increased odds of injury. CONCLUSION: Dysfunctional movement as identified by the FMS™ may be related to increased odds of injury during the competitive season in youth athletes. Consideration of an individual's movement within the context of their sport is necessary, as each sport and individual have unique characteristics. Addressing movement dysfunction may aid in injury reduction and potentially improve sport performance. LEVEL OF EVIDENCE: 1b.

Sport Specialization and Increased Injury Frequency in Youth Baseball Players: A Prospective Study.

CONTEXT: Sport specialization is thought to be a primary contributor to the throwing-related injury risk in youth baseball players. OBJECTIVE: To (1) establish arm-injury incidence in a cohort of male youth (9-12 years old) baseball players and (2) examine sport specialization and the frequency of arm injuries in the same cohort. DESIGN: Cohort study. SETTING: Greenville, South Carolina, youth baseball programs and tournaments. PATIENTS OR OTHER PARTICIPANTS: A total of 159 asymptomatic youth baseball players (age = 11.1 ± 1.1 years) were physically assessed and then were prospectively followed for 6.7 ± 1.5 months. MAIN OUTCOME MEASURE(S): Athlete demographics and playing and injury histories were initially recorded. Athlete-exposures and presence of arm injury were prospectively tracked. All injuries were physically confirmed by a licensed physical therapist. RESULTS: Youth players demonstrated an arm-injury incidence rate of 2.22 per 1000 athlete-exposures. Parents and players underestimated sport-specialization status based on the standard research definition (self versus research based: 31% versus 83%, respectively; P = .001). The frequency of arm injuries was higher in specialized players (100%) than in nonspecialized players (80%, P = .03) but did not differ between pitchers and position players (13.2% each, P = 1.00). CONCLUSIONS: Sport specialization was associated with throwing-related arm injuries in a small cohort of youth baseball players. It is concerning that 57.9% of parents and specialized players were unaware of the athletes' status. Larger studies with longer follow-up periods are needed to further evaluate injury-risk profiles in physically developing youth populations.

Cardiorespiratory Fitness and Risk of All-Cause, Cardiovascular Disease, and Cancer Mortality in Men With Musculoskeletal Conditions.

BACKGROUND: To investigate the association between cardiorespiratory fitness and risk of cardiovascular disease, cancer, and all-cause mortality in men with musculoskeletal conditions. METHODS: Participants were 12,728 men (mean age 47.0 [9.3] y) with a history of musculoskeletal conditions (including joint pain, low back pain, stiff joints, arthritis, osteoporosis, or gout) and were followed for all-cause mortality to December 31, 2003. Fitness was quantified by maximal treadmill exercise test and was categorized for analysis as low, moderate, and high performance. Cox proportional hazards regression was used to calculate hazard ratios and 95% confidence intervals. RESULTS: Overall, the multivariable-adjusted hazard ratios and 95% confidence intervals for mortality across incremental fitness categories were 1.00 (reference), 0.45 (0.30-0.68) and 0.35 (0.22-0.53), linear trend P < .01 for all-cause, 0.50 (0.23-1.10) and 0.29 (0.12-0.71), linear trend P = .02 for cardiovascular disease, and 0.38 (0.20-0.74) and 0.40 (0.20-0.80), linear trend P = .01 for cancer mortality. CONCLUSION: Among men with musculoskeletal conditions, higher fitness is associated with lower risk of death by cardiovascular disease, cancer, or any cause, independent of other risk factors.

Outcomes after a prone lumbar traction protocol for patients with activity-limiting low back pain: a prospective case series study.

OBJECTIVE: To determine outcomes after administration of a prone lumbar traction protocol. DESIGN: Prospective, longitudinal, case series. SETTING: Suburban, chiropractic practice. PARTICIPANTS: A total of 296 subjects with low back pain (LBP) and evidence of a degenerative and/or herniated intervertebral disk at 1 or more levels of the lumbar spine. We excluded patients involved in litigation and those receiving workers' compensation. INTERVENTION: An 8-week course of prone lumbar traction, using the vertebral axial decompression (VAX-D) system, consisting of five 30-minute sessions a week for 4 weeks, followed by one 30-minute session a week for 4 additional weeks. MAIN OUTCOME MEASURES: The numeric pain rating scale and the Roland-Morris Disability Questionnaire (RMDQ) were completed at preintervention, discharge (within 2 weeks of the last visit), and at 30 days and 180 days after discharge. Intention-to-treat strategies were used to account for those subjects lost to follow-up. RESULTS: A total of 250 (84.4%) subjects completed the treatment protocol. On the 30-day follow-up, 247 (83.4%) subjects were available; on the 180-day follow-up, data were available for 241 (81.4%) subjects. We noted significant improvements for all postintervention outcome scores when compared with preintervention scores (P<.01). CONCLUSIONS: Traction applied in the prone position using the VAX-D for 8 weeks was associated with improvements in pain intensity and RMDQ scores at discharge, and at 30 and 180 days after discharge in a sample of patients with activity-limiting LBP. Causal relationships between these outcomes and the intervention should not be made until further study is performed using randomized comparison groups.

Current understanding of lumbar intervertebral disc degeneration: a review with emphasis upon etiology, pathophysiology, and lumbar magnetic resonance imaging findings.

Degeneration of the lumbar intervertebral discs (IVDs) is highly prevalent in adults and is nearly universal in the elderly population. Degenerative changes within, and adjacent to, the IVDs are likely to contribute to a variety of pain syndromes; however, the exact association between these findings and symptoms remains speculative. Recent research has provided new information regarding the etiology, pathophysiology, and clinical relevance of degeneration of the IVD. This information will assist clinicians and researchers in understanding the development and clinical course of lumbar disc degeneration, as well as its potential impact upon patients seeking physical therapy care for back pain. The purposes of this clinical commentary are to review the structure and metabolic capacity of the normal and degenerative lumbar IVD, and to discuss factors that influence the onset and progression of disc degeneration. Lumbar magnetic resonance images will be used to illustrate the common findings associated with this condition.

Diffusion-weighted magnetic resonance imaging of normal and degenerative lumbar intervertebral discs: a new method to potentially quantify the physiologic effect of physical therapy intervention.

STUDY DESIGN: Observational, repeated measures design. OBJECTIVES: To determine the reliability of the apparent diffusion coefficient (ADC) calculated from diffusion-weighted magnetic resonance images (MRI) of the nuclear region of lumbar intervertebral discs (IVDs), to investigate the differences in the ADC based upon T2-signal intensity, and to examine the test-retest variation in these measures obtained from subjects undergoing serial, diffusion-weighted MRI scans. BACKGROUND: Impaired diffusion of water within the lumbar IVD is a central characteristic of degenerative disc disease. Diffusion-weighted MRI scans can provide quantitative estimates of water diffusion and may be useful to evaluate the physiologic effects of healing or the change in hydration related to interventions such as traction, manual therapy, or exercise on normal and degenerative lumbar IVDs. METHODS AND MEASURES: Thirty subjects underwent T2 -weighted and diffusion-weighted lumbar MRI scans. Twenty-one of these subjects underwent a second diffusion-weighted MRI scan 4 to 7 weeks after the initial scan. The ADC was calculated from midsagittal diffusion-weighted images for the IVDs of L1-2 to L5-S1. To assess reliability, repeated measures of the ADC were performed on the first 16 scans. The T2-signal of the nuclear region of each disc was classified as hyperintense, intermediate, or hypointense, and its relationship to the mean ADC of the nuclear region was determined. Test-retest variation in the ADC was described using the coefficient of variation (CV), plus or minus the width of the 95% confidence interval of the standard error of measurement (SEM). RESULTS: Intraclass correlation coefficients for estimates of intrarater and interrater reliability ranged from 0.95 to 0.99 and the SEM ranged from 0.006 to 0.026 X 10-3 mm2/s. The mean ADC was significantly greater for hyperintense IVDs compared to intermediate and hypointense IVDs. The CV plus or minus the 95% CI of the SEM between scans ranged from 9.0% to 13.6% for all discs, 6.1% to 10.1% for hyperintense discs, and 13.1% to 23.7% for intermediate discs. The prevalence of hypointense discs was too low to make meaningful judgments about their normal degree of variation over time. CONCLUSION: The ADC of the nuclear region of the lumbar IVDs may be reliably measured from diffusion-weighted images. Degenerative discs had lower mean ADC values than normal discs but demonstrated greater variation between scans. Diffusion-weighted imaging may be a useful procedure to assess change in diffusion of water in lumbar discs that occurs over time.

RISK FACTORS ASSOCIATED WITH NON-CONTACT ANTERIOR CRUCIATE LIGAMENT INJURY: A SYSTEMATIC REVIEW.

BACKGROUND: With the increasing number of individuals participating in sports every year, injury - specifically anterior cruciate ligament (ACL) injury - remains an inherent risk factor for participants. The majority of ACL injuries occur from a non-contact mechanism, and there is a high physical and financial burden associated with injury. Understanding the risk factors for ACL injury may aid in the development of prevention efforts. PURPOSE: The purpose of this review was to synthesize and appraise existing literature for risk factors associated with non-contact anterior cruciate ligament (ACL) injury in both sexes. STUDY DESIGN: Systematic review. METHODS: An electronic literature search was conducted utilizing the MEDLINE database and The Cochrane library for articles available through February 2016. All titles and abstracts were reviewed and full text articles meeting eligibility criteria were assessed in detail to determine inclusion or exclusion. Articles reviewed in full text were reviewed for scientific evidence of risk factors for ACL injury. Results from studies were extracted and initially classified as either intrinsic or extrinsic risk factors, and then further categorized based upon the evidence presented in the studies meeting inclusion criteria. Data extracted from eligible studies included general study characteristics (study design, sample characteristics), methodology, and results for risk factors included. RESULTS: Principal findings of this systematic review identified the following risk factors for ACL injury in both sexes: degrading weather conditions, decreased intercondylar notch index or width, increased lateral or posterior tibial plateau slope, decreased core and hip strength, and potential genetic influence. CONCLUSIONS: Neuromuscular and biomechanical risk factors may be addressed through neuromuscular preventative training programs. Though some extrinsic and other inherent physiological factors tend to be non-modifiable, attempts to improve upon those modifiable factors may lead to a decreased incidence of ACL injury. LEVEL OF EVIDENCE: 2a.