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The article presents the results of a study which investigated the biomechanics and physiology of the tire flip, a strongman competition event. Details of the experimental protocol are presented, which involved the video capture of the movement pattern involved, and measurements of the physiological effects of performing a tire flip.

Describes the art and inspirations of Harley Elliott and his associative approach to writing and visual art. Influence of Jack Garver; Examples of visual and literary works.

The sensitivity of the Wechsler Memory Scale with Russell's Revision to the effects of IQ and brain damage was assessed in groups of brain-damaged (N = 64) and nonbrain-damaged (N = 64) subjects. Brain-damaged and nonbrain-damaged subjects were divided into subgroups equated on age and IQ for each of three IQ ranges (80–89, 90–99, 100–109). Some Wechsler Memory Scale subtests were affected only by IQ, others were affected by IQ and brain-damage status, and still others were affected only by brain-damage status. Measures of recall efficiency were most useful in discriminating brain-damaged and nonbrain-damaged subjects. We concluded that specific Wechsler Memory Scale subtests are useful in assessing memory deficits in brain-damaged patients. [ABSTRACT FROM PUBLISHER]

It is unknown whether the biomechanics of the posterior ligamentous complex (PLC) are impaired in individuals undergoing surgery for adult spinal deformity (ASD). Characterizing these properties may improve our understanding of proximial junctional kyphosis (PJK, defined as proximal junctional angle [PJA] of >10deg from UIV-1 to UIV+2), as well as proximal junctional failure (PJF, symptomatic PJK requiring revision). Ligament biomechanical properties will be associated with PJK and failure PJF. A prospective observational study. Intraoperative biopsies of PLC were obtained from 32 consecutive spinal fusions for ASD (>4 levels). Ligament peak force, tensile stress, tensile strain and elastic modulus (EM) were measured with a materials testing system. Biomechanical properties and tissue dimensions were correlated with age, gender, BMI, vitamin D level, osteoporosis, sagittal alignment, PJA and change in PJA preoperatively (PRE), within 3 months (3MO), and at one-year (1YR) postoperatively. Mean (SD) PLC peak force was 207.8(100.6) N, tensile stress was 3.3(1.5) MPa, tensile strain was 1.9(1.2) mm/mm, and EM was 7.1(5.1) MPa. Mean PLC length was 5.9(2.6) mm, thickness was 3.8(1.5) mm, and width was 17.7(4.7) mm. Longer and thinner ligaments were associated with greater PJA change at 3MO (r=0.38, p=0.04; r=0.34, p=0.08 respectively), and thinner ligaments were associated with greater PJA change at 1YR (r=0.57, p=0.01). Greater EM was associated with greater 3MO (r=0.43, p=0.03) and 1YR (r=0.54, p=0.03) PJA. Age was associated with 3MO PJA (r=0.41, p=0.03). EM remained related to PJA when correcting for age (p=0.01). Five had a change in PJA of >10° from PRE to 1YR while PJA change from 3MO to 1YR was 0.6°(3.6). EM was significantly higher in individuals who required revision surgery within 1YR (16.2 (9.7) MPa) versus those who did not (6.5(3.6) MPa, p=0.003). Neither PRE sagittal alignment nor change at 3MO were related to change in PJA or need for revision surgery (p>0.10). At 1YR, three had PJF (2 for PJK, 1 discitis). Biomechanical properties of the PLC may be associated with higher risk for proximal failure. Ligaments that are longer, thinner and less elastic are associated with higher postoperative PJA. Furthermore, stiffer EM of the ligament is associated with the need for revision surgery. This abstract does not discuss or include any applicable devices or drugs. [ABSTRACT FROM AUTHOR]

Purpose: It is unknown whether the biomechanics of the posterior ligamentous complex (PLC) are impaired in individuals undergoing surgery for adult spinal deformity (ASD). Characterizing these properties may improve our understanding of proximal junctional kyphosis (PJK; defined as proximal junctional angle [PJA] of >10 deg from UIV-1 to UIV + 2), as well as proximal junctional failure (PJF; symptomatic PJK requiring revision). The purpose of this prospective observational study is to compare biomechanical properties of the PLC in individuals with ASD who do, and do not develop PJK or PJF within 1 year of spinal fusion surgery., Methods: Intraoperative biopsies of PLC were obtained from 32 consecutive patients undergoing spinal fusions for ASD (>4 levels). Ligament peak force, tensile stress, tensile strain, and elastic modulus (EM) were measured with a materials testing system. Biomechanical properties and tissue dimensions were correlated with age, gender, BMI, vitamin D level, osteoporosis, sagittal alignment, PJA and change in PJA preoperatively, within 3 months, and at 1 year postoperatively., Results: Longer ligaments were associated with greater PJA change at 3 months ( p  = 0.04), and thinner ligaments were associated with greater PJA change at 1 year ( r  = 0.57, p  = 0.01). Greater EM was associated with greater PJA at both 3 months and 1 year ( p  = 0.03). Five participants had a change in PJA of >10 1 year postoperatively, and three participants demonstrated PJF. EM was significantly higher in individuals who required revision surgery ( p  = 0.003), and ligament length was greater ( p  = 0.03). Preoperative sagittal alignment was not related to incidence of revision surgery ( p  > 0.10)., Conclusions: The biomechanical properties of the PLC may be associated with higher risk for proximal failure. Ligaments that are longer, thinner, and less elastic are associated with higher postoperative PJA. Furthermore stiffer EM of the ligament is associated with the need for revision surgery., Competing Interests: Author Bahar Shahidi is a consultant for San Diego Spine Foundation. Gregory M. Mundis is a consultant for Carlsmed, Nuvasive, Seaspine, SIBone, and Viseon; holds stock/stock options in Alphatec, Nuvasive, and Orthofix Inc; receives IP royalties from Nuvasive, Seaspine, and Stryker. Robert K. Eastlack is a consultant for Aesculap, Biedermann‐Motech, Johnson & Johnson, Medtronic, Neo Medical NuVasive, SeaSpine, & SIBone; holds stock in Alphatec, NuVasive, SeaSpine, SIBone, and Spine Innovations. These disclosures/relationships did not influence this research, and the authors have no conflicts., (© 2023 The Authors. JOR Spine published by Wiley Periodicals LLC on behalf of Orthopaedic Research Society.)

Purpose: The purpose of this study was to understand potential baseline transcriptional expression differences in paraspinal skeletal muscle from patients with different underlying lumbar pathologies by comparing multifidus gene expression profiles across individuals with either disc herniation, facet arthropathy, or degenerative spondylolisthesis., Methods: Multifidus biopsies were obtained from patients (n = 44) undergoing lumbar surgery for either disc herniation, facet arthropathy, or degenerative spondylolisthesis. Diagnostic categories were based on magnetic resonance images, radiology reports, and intraoperative reports. Gene expression for 42 genes was analysed using qPCR. A one-way analysis of variance was performed for each gene to determine differences in expression across diagnostic groups. Corrections for multiple comparisons across genes (Benjamini-Hochberg) and for between-group post hoc comparisons (Sidak) were applied., Results: Adipogenic gene (ADIPOQ) expression was higher in the disc herniation group when compared to the facet arthropathy group (p = 0.032). Adipogenic gene (PPARD) expression was higher in the degenerative spondylolisthesis group when compared to the disc herniation group (p = 0.013), although absolute gene expression levels for all groups was low. Fibrogenic gene (COL3A1) had significantly higher expression in the disc herniation group and facet arthropathy group when compared to the degenerative spondylolisthesis group (p < 0.001 and p = 0.038, respectively). When adjusted for multiple comparisons, only COL3A1 remained significant (p = 0.012)., Conclusion: Individuals with disc herniation and facet arthropathy demonstrate higher COL3A1 gene expression compared to those with degenerative spondylolisthesis. Future research is required to further understand the biological relevance of these transcriptional differences., (© 2023. The Author(s).)

Purpose: Although recommendations for effective heat acclimation (HA) strategies for many circumstances exist, best-practice HA protocols specific to elite female team-sport athletes are yet to be established. Therefore, the authors aimed to investigate the effectiveness and retention of a passive HA protocol integrated in a female Olympic rugby sevens team training program., Methods: Twelve elite female rugby sevens athletes undertook 10 days of passive HA across 2 training weeks. Tympanic temperature (TTymp), sweat loss, heart rate, and repeated 6-second cycling sprint performance were assessed using a sport-specific heat stress test Pre-HA, after 3 days (Mid-HA), after 10 days (Post-HA), and 15 days post-HA (Decay)., Results: Compared with Pre-HA, submaximal TTymp was lower Mid-HA and Post-HA (both by -0.2 [0.7] °C; d ≥ 0.71), while resting TTymp was lower Post-HA (by -0.3 [0.2] °C; d = 0.81). There were no differences in TTymp at Decay compared with Pre-HA, nor were there any differences in heart rate or sweat loss at any time points. Mean peak 6-second power output improved Mid-HA and Post-HA (76 [36] W; 75 [34] W, respectively; d ≥ 0.45) compared with Pre-HA. The observed performance improvement persisted at Decay by 65 (45) W (d = 0.41)., Conclusions: Ten days of passive HA can elicit some thermoregulatory and performance benefits when integrated into a training program in elite female team-sport athletes. However, such a protocol does not provide a sufficient thermal impulse for thermoregulatory adaptations to be retained after 15 days with no further heat stimulus.

Background: Lumbar spine pathology is a common feature of lower back and/or lower extremity pain and is associated with observable degenerative changes in the lumbar paraspinal muscles that are associated with poor clinical prognosis. Despite the commonly observed phenotype of muscle degeneration in this patient population, its underlying molecular mechanisms are not well understood. The aim of this study was to investigate the relationships between groups of genes within the atrophic, myogenic, fibrogenic, adipogenic, and inflammatory pathways and multifidus muscle health in individuals undergoing surgery for lumbar spine pathology., Methods: Multifidus muscle biopsies were obtained from patients (n = 59) undergoing surgery for lumbar spine pathology to analyze 42 genes from relevant adipogenic/metabolic, atrophic, fibrogenic, inflammatory, and myogenic gene pathways using quantitative polymerase chain reaction. Multifidus muscle morphology was examined preoperatively in these patients at the level and side of biopsy using T2-weighted magnetic resonance imaging to determine whole muscle compartment area, lean muscle area, fat cross-sectional areas, and proportion of fat within the muscle compartment. These measures were used to investigate the relationships between gene expression patterns and muscle size and quality., Results: Relationships between gene expression and imaging revealed significant associations between decreased expression of adipogenic/metabolic gene (PPARD), increased expression of fibrogenic gene (COL3A1), and lower fat fraction on MRI (r = -0.346, p = 0.018, and r = 0.386, p = 0.047 respectively). Decreased expression of myogenic gene (mTOR) was related to greater lean muscle cross-sectional area (r = 0.388, p = 0.045)., Conclusion: Fibrogenic and adipogenic/metabolic genes were related to pre-operative muscle quality, and myogenic genes were related to pre-operative muscle size. These findings provide insight into molecular pathways associated with muscle health in the presence of lumbar spine pathology, establishing a foundation for future research that addresses how these changes impact outcomes in this patient population., (© 2022. The Author(s).)