Force and EMG Comparison between a weight-bearing clinical assessment of hip strength assessment and non-weightbearing tasks

Purpose: Altered hip strength is a risk factor for lower extremity injury but its relationship to biomechanical dysfunction is debated. Hip strength assessment methods are criticized for using unidirectional, non-weight-bearing positions which may not be representative of athletic activity and may affect comparison to biomechanical analysis of athletic tasks. A weight-bearing task may better represent hip muscle function during these movements. The aim of this study was to identify EMG and force differences for a clinical weight-bearing method of hip strength (the squat-hold) to traditional non-weight-bearing maximal voluntary isometric contractions (MVICs) for hip abduction, extension, and external rotation. Methods: Twenty-nine healthy volunteers (23 female, 6 male; 23.3±5.8 years) performed the squat-hold, sidelying abduction, prone extension, and seated hip external rotation MVICs. The squat-hold was performed by exerting a bilateral, maximal force against a rigid strap encircling both knees in a semi-squatted position. Surface electromyography (EMG) recorded peak activation of the gluteus medius (GMed), gluteus maximus (Gmax), and tensor fascia lata (TFL) and a handheld dynamometer simultaneously measured force during all tasks. Peak activation was compared between the squat-hold and each MVIC using paired t-tests. Force was compared across tasks using a one-way ANOVA. Results: Greater force was observed during the squat-hold than the external rotation MVIC, but abduction and extension MVICs yielded greater force than the squat-hold. GMax activation was higher during the squat-hold than the external rotation task. TFL activation was higher during the abduction MVIC than the squat-hold but GMed activation was similar across tasks. Peak GMax activation was similar between the extension MVIC and squat-hold. Conclusions: Squat-hold force may have been reduced due to altered gluteal moment arms, which affected the length-tension relationship. Clinicians should consider the squat-hold as an alternative assessment of external rotation force, but should continue to assess abduction and extension force with MVICs. Researchers should examine positions optimizing length-tension relationships to better relate motor function and movement patterns

Developing Clinical and Research Priorities for Pain and Psychological Features in People With Patellofemoral Pain:An International Consensus Process With Health Care Professionals

OBJECTIVE: To decide clinical and research priorities on pain features and psychological factors in persons with patellofemoral pain. DESIGN: Consensus development process. METHODS: We undertook a 3-stage process consisting of (1) updating 2 systematic reviews on quantitative sensory testing of pain features and psychological factors in patellofemoral pain, (2) an online survey of health care professionals and persons with patellofemoral pain, and (3) a consensus meeting with expert health care professionals. Participants responded that they agreed, disagreed, or were unsure that a pain feature or psychological factor was important in clinical practice or as a research priority. Greater than 70% participant agreement was required for an item to be considered important in clinical practice or a research priority. RESULTS: Thirty-five health care professionals completed the survey, 20 of whom attended the consensus meeting. Thirty persons with patellofemoral pain also completed the survey. The review identified 5 pain features and 9 psychological factors—none reached 70% agreement in the patient survey, so all were considered at the meeting. Afte the meeting, pain catastrophizing, fear-avoidance beliefs, and pain self-efficacy were the only factors considered clinically important. All but the therma pain tests and 3 psychological factors were consid ered research priorities. CONCLUSION: Pain catastrophizing, pain self-efficacy, and fear-avoidance beliefs were factors considered important in treatment planning, clinical examination, and prognostication. Quantitative sensory tests for pain were not regarded as clinically important but were deemed to be research priorities, as were most psychological factors.</p

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Reliability and Construct Validity of the Single-leg Landing Error Scoring System (SL-LESS) in Physically Active Females

PURPOSE Single-leg landings are common in sport and often result in injury, however a rubric to evaluate biomechanics during single-leg jump landing (SLL) does not exist. The Single-Leg Landing Error Scoring System (SL-LESS) is a rubric developed to evaluate movement during SLL. The purpose of this study was to 1) determine inter- and intra-rater reliability of the SL-LESS, 2) and determine the content and construct validity of the SL-LESS when evaluating SLL METHOD 28 healthy females completed SLL on two days while 2D and 3D data were recorded. 3D angles were trunk flexion/lateral-flexion, pelvic tilt/contralateral drop, hip flexion/adduction, and knee flexion/abduction at initial contact (IC) and maximum knee flexion (MKF). Two raters used the SL-LESS rubric to score 2D videos each day. Participants were grouped by total SL-LESS score (≤ 2 errors=good; ≥4 errors=poor landers). Kappa, prevalence- and bias-adjusted kappa (PABAK), and percent agreement were calculated for inter- and intra-rater reliability between rubric items. Total score reliability was evaluated using an ICC. Differences in 3D angles, knee abduction moment(KABDM), and vertical ground reaction force(vGRF)between good and poor landers were evaluated using a one-way ANOVA (construct validity). p RESULTS SL-LESS item inter-rater (Average κ=0.21±0.21, PABAK=0.60±0.28, % agreement=0.78±0.13); and intra-rater (Average Κ=0.30±0.21, PABAK=0.60±0.21, %agreement= 0.79±0.12) reliability were moderate. Inter- (ICC(2,1)=0.50) and intra-rater (ICC(3,1)=0.56) reliability for total score were moderate. Good landers displayed significantly greater hip and trunk flexion at IC, and hip and knee flexion at MKF, lower KABDM at initial contact, and lower vGRF (p CONCLUSIONS The SL-LESS can reliably be used to evaluate the SLL movement and can discriminate between “stiff” landings with upright posture and high impact force from “soft” landings with flexed landing posture with lower impact force

Exploring the Pain in Patellofemoral Pain: A Systematic Review and Meta-Analysis Examining Signs of Central Sensitization

Background Patellofemoral pain (PFP) has high recurrence rates and minimal long-term treatment success. Central sensitization refers to dysfunctional pain modulation that occurs when nociceptive neurons become hyperresponsive. Researchers in this area of PFP have been increasingly productive in the past decade. Objective To determine whether evidence supports manifestations of central sensitization in individuals with PFP. Data Sources We searched MeSH terms for quantitative sensory testing (QST) pressure pain thresholds (PPTs), conditioned pain modulation (CPM), temporal summation, sensitization, hyperalgesia, and anterior knee pain or PFP in PubMed, SPORTDiscus, CINAHL, Academic Search Complete, and EBSCOhost. Study Selection Peer-reviewed studies that were written in English and published between 2005 and 2020 and investigated QST or pain mapping in a sample with PFP were included in this review. Data Extraction The initial search yielded 140 articles. After duplicates were removed, 78 abstracts were reviewed. The full text of 21 studies was examined, and we included 15 studies in our evaluation: 6 in the meta-analysis, 4 in the systematic review, and 5 in both the meta-analysis and systematic review. Data Synthesis A random-effects meta-analysis was conducted for 4 QST variables (local PPTs, remote PPTs, CPM, temporal summation). Strong evidence supported lower local and remote PPTs, impaired CPM, and facilitated temporal summation in individuals with PFP compared with pain-free individuals. Evidence for heat and cold pain thresholds was conflicting. Pain mapping demonstrated expanding pain patterns associated with long duration of PFP symptoms. Conclusions Signs of central sensitization were present in individuals with PFP, indicating altered pain modulation. The etiologic and treatment models of PFP should reflect the current body of evidence regarding central sensitization. Signs of central sensitization should be monitored clinically, and treatments with central effects should be considered as part of a multimodal plan of care

Fast third-order optical nonlinearities in metal alloy nanocluster composite glass: negative sign of the nonlinear refractive index

The fast component of the nonlinear refractive index, n2, of a composite film formed by alloy nanoparticles embedded in silica was measured by Z-scan technique, in conditions free from cumulative heating effects. By using a single 6 ps long laser pulse at 1 Hz, 527 nm of wavelength, a negative sign of n2 was evidenced. An explanation of this result is suggested, based on the dielectric confinement effect. The fast refractive index value, in modulus, is of the order of 10exp-10 cm2/W

Developing Clinical and Research Priorities for Pain and Psychological Features in People With Patellofemoral Pain: An International Consensus Process With Health Care Professionals.

OBJECTIVE: To decide clinical and research priorities on pain features and psychological factors in persons with patellofemoral pain. DESIGN: Consensus development process. METHODS: We undertook a 3-stage process consisting of (1) updating 2 systematic reviews on quantitative sensory testing of pain features and psychological factors in patellofemoral pain, (2) an online survey of health care professionals and persons with patellofemoral pain, and (3) a consensus meeting with expert health care professionals. Participants responded that they agreed, disagreed, or were unsure that a pain feature or psychological factor was important in clinical practice or as a research priority. Greater than 70% participant agreement was required for an item to be considered important in clinical practice or a research priority. RESULTS: Thirty-five health care professionals completed the survey, 20 of whom attended the consensus meeting. Thirty persons with patellofemoral pain also completed the survey. The review identified 5 pain features and 9 psychological factors-none reached 70% agreement in the patient survey, so all were considered at the meeting. After the meeting, pain catastrophizing, fear-avoidance beliefs, and pain self-efficacy were the only factors considered clinically important. All but the thermal pain tests and 3 psychological factors were considered research priorities. CONCLUSION: Pain catastrophizing, pain self-efficacy, and fear-avoidance beliefs were factors considered important in treatment planning, clinical examination, and prognostication. Quantitative sensory tests for pain were not regarded as clinically important but were deemed to be research priorities, as were most psychological factors. J Orthop Sports Phys Ther 2022;52(1):29-39. doi:10.2519/jospt.2022.10647