Browsing by Author "Warden, Stuart J."
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Item Achilles tendon material properties are greater in the jump leg of jumping athletes(ISMNI, 2016-06) Bayliss, Amy J.; Weatherholt, Alyssa M.; Crandall, Trent T.; Farmer, Danielle L.; McConnell, Jethro C.; Crossley, K. M.; Warden, Stuart J.; Department of Physical Therapy, School of Health and Rehabilitation SciencesPurpose: The Achilles tendon (AT) must adapt to meet changes in demands. This study explored AT adaptation by comparing properties within the jump and non-jump legs of jumping athletes. Non-jumping control athletes were included to control limb dominance effects. Methods: AT properties were assessed in the preferred (jump) and non-preferred (lead) jumping legs of male collegiate-level long and/or high jump (jumpers; n=10) and cross-country (controls; n=10) athletes. Cross-sectional area (CSA), elongation, and force during isometric contractions were used to estimate the morphological, mechanical and material properties of the ATs bilaterally. Results: Jumpers exposed their ATs to more force and stress than controls (all p≤0.03). AT force and stress were also greater in the jump leg of both jumpers and controls than in the lead leg (all p<0.05). Jumpers had 17.8% greater AT stiffness and 24.4% greater Young’s modulus in their jump leg compared to lead leg (all p<0.05). There were no jump versus lead leg differences in AT stiffness or Young’s modulus within controls (all p>0.05). Conclusion: ATs chronically exposed to elevated mechanical loading were found to exhibit greater mechanical (stiffness) and material (Young’s modulus) properties.Item Adaptation of the proximal humerus to physical activity: a within-subject controlled study in baseball players(Elsevier, 2019-01-08) Warden, Stuart J.; Carballido-Gamio, Julio; Avin, Keith G.; Kersh, Mariana E.; Fuchs, Robyn K.; Krug, Roland; Bice, Ryan; Physical Therapy, School of Health and Human SciencesThe proximal humerus is a common, yet understudied site for osteoporotic fracture. The current study explored the impact of prolonged physical activity on proximal humerus bone health by comparing bone properties between the throwing and nonthrowing arms within professional baseball players. The proximal humerus in throwing arms had 28.1% (95% CI, 17.8 to 38.3%) greater bone mass compared to nonthrowing arms, as assessed using dual-energy x-ray absorptiometry. At the level of the surgical neck, computed tomography revealed 12.0% (95% CI, 8.2 to 15.8%) greater total cross-sectional area and 31.0% (95% CI, 17.8 to 44.2%) greater cortical thickness within throwing arms, which contributed to 56.8% (95% CI, 44.9 to 68.8%) greater polar moment of inertia (i.e., estimated ability to resist torsional forces) compared to nonthrowing arms. Within the humeral head and greater tubercle regions, throwing arms had 3.1% (95% CI, 1.1 to 5.1%) more trabecular bone, as assessed using high-resolution magnetic resonance imaging. Three-dimensional mapping of voxel- and vertex-wise differences between arms using statistical parametric mapping techniques revealed throwing arms had adaptation within much of the proximal diaphysis, especially the posterolateral cortex. The pattern of proximal diaphysis adaptation approximated the pattern of strain energy distribution within the proximal humerus during a fastball pitch derived from a musculoskeletal and finite element model in a representative player. These data demonstrate the adaptive ability of the proximal humerus to physical activity-related mechanical loads. It remains to be established how they translate to exercise prescription to improve bone health within the proximal humerus, however, they provide unique insight into the relationship between prolonged loading and skeletal adaptation at a clinically relevant osteoporotic site.Item Age-Related Changes in Proximal Humerus Bone Health in White Males(Office of the Vice Chancellor for Research, 2012-04-13) Fuchs, Robyn K.; Mantila Roosa, Sara M.; Hurd, Andrea L; Warden, Stuart J.The proximal humerus is a common site for osteoporotic fracture during aging, accounting for up to 5% of fractures to the appendicular skeleton. While falls onto an outstretched hand are usually physically responsible for proximal humerus fractures, the ability of the underlying bone to resist applied loads must also play a role. Few studies have assessed proximal humerus bone health with aging. The aim of the current study was to explore age-related bone changes at the proximal humerus in men. A cross-sectional study design was used to assess peripheral quantitative computed tomography (pQCT)-derived bone properties of the proximal humerus in a cohort of 112 white males (age range = 30-85 yrs). A tomographic slice of the non-dominant upper extremity was acquired at 80% of humeral length proximal from its distal end—a location corresponding to the surgical neck of the humerus. Images were assessed for cortical (Ct.BMC) and trabecular (Tb.BMC) BMC, total (Tt.Ar), cortical (Ct.Ar) and medullary (Me.Ar) area, periosteal (Ps.Pm) and endosteal (Es.Pm) perimeter, cortical thickness (Ct.Th), and bone strength index for compression (BSIc). BSIc was calculated as the product of Tt.Ar and the square of total volumetric BMD. Data were plotted against age and linear regression lines assessed for their slope. Slopes were subsequently converted to percent change in the bone property per year. During aging, the proximal humerus expanded with Tt.Ar and Ps.Pm increasing at rates of 0.40%/yr and 0.19%/yr, respectively. However, Me.Ar (0.62%/yr) and Es.Pm (0.34%/yr) expanded at faster rates such that there was net loss of both Ct.BMC (-0.23%/yr) and Tb.BMC (-1.08%/yr). Also, the more rapid expansion of Me.Ar relative to Tt.Ar meant that Ct.Ar (-0.15%/yr) and Ct.Th (-0.34%/yr) both decreased with age. The net result of these mass and structural changes was progressive loss of bone strength with age, as indicated by a 0.44%/yr decline in BSIc. These data provide a picture of bone changes at the proximal humerus during aging. They suggest that between age 30 and 80 yrs, approximately 54% and 11% of Tb.BMC and Ct.BMC at the proximal humerus is lost, respectively. They also suggest that compressive strength of the proximal humerus declines by 22% between age 30 and 80 years. These declines in proximal humerus bone health have implications for fracture risk at this location during aging.Item Baseball and softball pitchers are distinct within-subject controlled models for exploring proximal femur adaptation to physical activity(Springer, 2019-01-21) Fuchs, Robyn K.; Thompson, William R.; Weatherholt, Alyssa M.; Warden, Stuart J.; Physical Therapy, School of Health and Human SciencesPurpose: Within-subject controlled models in individuals who preferentially load one side of the body enable efficient exploration of the skeletal benefits of physical activity. There is no established model of physical activity-induced side-to-side differences (i.e., asymmetry) at the proximal femur. Methods: Proximal femur asymmetry was assessed via dual-energy x-ray absorptiometry in male jumping athletes (JMP, n=16), male baseball pitchers (BB, n=21), female fast-pitch softball pitchers (SB, n=22), and controls (CON, n=42). The jumping leg was the dominant leg in JMP, whereas in BB, SB and CON the dominant leg was contralateral to the dominant/throwing arm. Results: BB and SB had 5.5% (95%CI, 3.9 to 7.0%) and 6.5% (95%CI, 4.8 to 8.2%) dominant-to-nondominant leg differences for total hip areal bone mineral density (aBMD), with the asymmetry being greater than both CON and JMP (p<0.05). BB and SB also possessed dominant-to-nondominant leg differences in femoral neck and trochanteric aBMD (p<0.001). SB had 9.7% (95% CI, 6.4 to 13.0%) dominant-to-nondominant leg differences in femoral neck bone mineral content, which was larger than any other group (p≤0.006). At the narrow neck, SB had large (>8%) dominant-to-nondominant leg differences in cross-sectional area, cross-sectional moment of inertia and section modulus, which were larger than any other group (p≤0.02). Conclusion: Male baseball and female softball pitchers are distinct within-subject controlled models for exploring adaptation of the proximal femur to physical activity. They exhibit adaptation in their dominant/landing leg (i.e., leg contralateral to the throwing arm), but the pattern differs with softball pitchers exhibiting greater femoral neck adaptation.Item Bone Microarchitecture and Strength Adaptation to Physical Activity: A Within-Subject Controlled, HRpQCT Study(Wolters Kluwer, 2021) Warden, Stuart J.; Wright, Christian S.; Fuchs, Robyn K.; Physical Therapy, School of Health and Rehabilitation SciencesPurpose Physical activity benefits bone mass and cortical bone size. The current study assessed the impact of chronic (≥10 years) physical activity on trabecular microarchitectural properties and micro-finite element (μFE) analyses of estimated bone strength. Methods Female collegiate-level tennis players (n=15; age=20.3±0.9 yrs) were used as a within-subject controlled model of chronic unilateral upper-extremity physical activity. Racquet-to-nonracquet arm differences at the distal radius and radial diaphysis were assessed using high-resolution peripheral computed tomography (HRpQCT). The distal tibia and tibial diaphysis in both legs were also assessed, and cross-country runners (n=15; age=20.8±1.2 yrs) included as controls. Results The distal radius of the racquet arm had 11.8% (95% confidence interval [CI], 7.9 to 15.7%) greater trabecular bone volume/tissue volume, with trabeculae that were greater in number, thickness, connectivity, and proximity to each other than in the nonracquet arm (all p<0.01). Combined with enhanced cortical bone properties, the microarchitectural advantages at the distal radius contributed a 18.7% (95% CI, 13.0 to 24.4%) racquet-to-nonracquet arm difference in predicted load before failure. At the radial diaphysis, predicted load to failure was 9.6% (95% CI, 6.7 to 12.6%) greater in the racquet vs. nonracquet arm. There were fewer and smaller side-to-side differences at the distal tibia; however, the tibial diaphysis in the leg opposite the racquet arm was larger with a thicker cortex and had 4.4% (95% CI, 1.7 to 7.1%) greater strength than the contralateral leg. Conclusion Chronically elevated physical activity enhances trabecular microarchitecture and μFE estimated strength, furthering observations from short-term longitudinal studies. The data also demonstrate tennis players exhibit crossed symmetry wherein the leg opposite the racquet arm possesses enhanced tibial properties compared to in the contralateral leg.Item Cortical and trabecular bone benefits of mechanical loading are maintained long term in mice independent of ovariectomy.(Wiley, 2014) Warden, Stuart J.; Galley, Matthew R.; Hurd, Andrea L.; Richard, Jeffrey S.; George, Lydia A.; Guildenbecher, Elizabeth A.; Barker, Rick G.; Fuchs, Robyn K.; Health Sciences, School of Health and Rehabilitation SciencesSkeletal loading enhances cortical and trabecular bone properties. How long these benefits last after loading cessation remains an unresolved, clinically relevant question. This study investigated long-term maintenance of loading-induced cortical and trabecular bone benefits in female C57BL/6 mice and the influence of a surgically induced menopause on the maintenance. Sixteen-week-old animals had their right tibia extrinsically loaded 3 days/week for 4 weeks using the mouse tibial axial compression loading model. Left tibias were not loaded and served as internal controls. Animals were subsequently detrained (restricted to cage activities) for 0, 4, 8, 26, or 52 weeks, with ovariectomy (OVX) or sham-OVX surgery being performed at 0 weeks detraining. Loading increased midshaft tibia cortical bone mass, size, and strength, and proximal tibia bone volume fraction. The cortical bone mass, area, and thickness benefits of loading were lost by 26 weeks of detraining because of heightened medullary expansion. However, loading-induced benefits on bone total area and strength were maintained at each detraining time point. Similarly, the benefits of loading on bone volume fraction persisted at all detraining time points. The long-term benefits of loading on both cortical and trabecular bone were not influenced by a surgically induced menopause because there were no interactions between loading and surgery. However, OVX had independent effects on cortical bone properties at early (4 and 8 weeks) detraining time points and trabecular bone properties at all detraining time points. These cumulative data indicate loading has long-term benefits on cortical bone size and strength (but not mass) and trabecular bone morphology, which are not influenced by a surgically induced menopause. This suggests skeletal loading associated with physical activity may provide long-term benefits by preparing the skeleton to offset both the cortical and trabecular bone changes associated with aging and menopause.Item Effects of exercise and manual therapy on pain associated with hip osteoarthritis: a systematic review and meta‐analysis(BMJ, 2016-04) Beumer, Lucy; Wong, Jennie; Warden, Stuart J.; Kemp, Joanne L.; Foster, Paul; Crossley, Kay M.; Department of Health Sciences, School of Health and Rehabilitation SciencesAim To explore the effects of exercise (water-based or land-based) and/or manual therapies on pain in adults with clinically and/or radiographically diagnosed hip osteoarthritis (OA). Methods A systematic review and meta-analysis was performed, with patient reported pain assessed using a visual analogue scale (VAS) or the Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain subscale. Data were grouped by follow-up time (0–3 months=short term; 4–12 months=medium term and; >12 months=long term), and standardised mean differences (SMD) with 95% CIs were used to establish intervention effect sizes. Study quality was assessed using modified PEDro scores. Results 19 trials were included. Four studies showed short-term benefits favouring water-based exercise over minimal control using the WOMAC pain subscale (SMD −0.53, 95% CI −0.96 to −0.10). Six studies supported a short-term benefit of land-based exercise compared to minimal control on VAS assessed pain (SMD −0.49, 95% CI −0.70 to −0.29). There were no medium (SMD −0.23, 95% CI −0.48 to 0.03) or long (SMD −0.22, 95% CI −0.51 to 0.06) term benefits of exercise therapy, or benefit of combining exercise therapy with manual therapy (SMD −0.38, 95% CI −0.88 to 0.13) when compared to minimal control. Conclusions Best available evidence indicates that exercise therapy (whether land-based or water-based) is more effective than minimal control in managing pain associated with hip OA in the short term. Larger high-quality RCTs are needed to establish the effectiveness of exercise and manual therapies in the medium and long term.Item The Effects of Instrument-Assisted Cross Fiber Massage on Ligament Healing(2010-07-21T19:26:44Z) Loghmani, Mary T.; Warden, Stuart J.; Burr, David B.; Robling, Alex G.; Seifert, Mark Frederick; Turner, Charles H.Ligament injury is one of the most prevalent musculoskeletal disorders that may lead to disability or disease, such as osteoarthritis. Conservative interventions which accelerate or augment ligament healing are needed to enhance therapeutic outcomes. The purpose of this research agenda was to investigate the tissue level effects of a type of manual therapy, cross fiber massage (CFM), in particular instrument-assisted CFM (IACFM), on ligament healing. Bilateral knee medial collateral ligament (MCL) injuries were created using an established rodent model where one MCL received IACFM treatment and the other untreated MCL served as a within subjects control. The short and long term effects of IACFM on the biomechanical and histological properties of repairing ligaments were investigated. Tensile mechanical testing was performed to determine ligament mechanical properties. Ligament histology was examined under light microscopy and scanning electron microscopy. IACFM was found to accelerate early ligament healing (4 weeks post-injury), possibly via favorable effects on collagen formation and organization, but minimal improvement was demonstrated in later healing (12 weeks post-injury). Regional blood flow and angiogenesis were investigated as possible mechanisms underlying the accelerated healing found in IACFM-treated ligaments. Laser Doppler perfusion imaging was used to investigate vascular function. Micro-computed tomography was used to determine vascular structural parameters. Compared to untreated contralateral injured controls, IACFM-treated injured knees demonstrated a delayed increase in blood flow and altered microvascular structure, possibly suggesting angiogenesis. Mechanotransduction is discussed as a mechanism for the beneficial effects of CFM in that application of a mechanical force was found to enhance biomechanical and histological properties as well as vascular function and structure acutely in healing ligaments. Although this thesis focused on IACFM treatment of injured knee ligaments, it is plausible for concepts to apply to other manual modalities that offer conservative alternatives to invasive procedures or pharmaceuticals in the treatment of soft tissue injuries.Item Electroacupuncture Promotes Central Nervous System-Dependent Release of Mesenchymal Stem Cells(Wiley, 2017-05) Salazar, Tatiana E.; Richardson, Matthew R.; Beli, Eleni; Ripsch, Matthew S.; George, John; Kim, Youngsook; Duan, Yaqian; Moldovan, Leni; Yan, Yuanqing; Bhatwadekar, Ashay; Jadhav, Vaishnavi; Smith, Jared A.; McGorray, Susan; Bertone, Alicia L.; Traktuev, Dmitri O.; March, Keith L.; Colon-Perez, Luis M.; Avin, Keith; Sims, Emily; Mund, Julie A.; Case, Jamie; Deng, Shaolin; Kim, Min Su; McDavitt, Bruce; Boulton, Michael E.; Thinschmidt, Jeffrey; Calzi, Sergio Li; Fitz, Stephanie D.; Fuchs, Robyn K.; Warden, Stuart J.; McKinley, Todd; Shekhar, Anantha; Febo, Marcelo; Johnson, Phillip L.; Chang, Lung Ji; Gao, Zhanguo; Kolonin, Mikhail G.; Lai, Song; Ma, Jinfeng; Dong, Xinzhong; White, Fletcher A.; Xie, Huisheng; Yoder, Mervin C.; Grant, Maria B.; Ophthalmology, School of MedicineElectroacupuncture (EA) performed in rats and humans using limb acupuncture sites, LI-4 and LI-11, and GV-14 and GV-20 (humans) and Bai-hui (rats) increased functional connectivity between the anterior hypothalamus and the amygdala and mobilized mesenchymal stem cells (MSCs) into the systemic circulation. In human subjects, the source of the MSC was found to be primarily adipose tissue, whereas in rodents the tissue sources were considered more heterogeneous. Pharmacological disinhibition of rat hypothalamus enhanced sympathetic nervous system (SNS) activation and similarly resulted in a release of MSC into the circulation. EA-mediated SNS activation was further supported by browning of white adipose tissue in rats. EA treatment of rats undergoing partial rupture of the Achilles tendon resulted in reduced mechanical hyperalgesia, increased serum interleukin-10 levels and tendon remodeling, effects blocked in propranolol-treated rodents. To distinguish the afferent role of the peripheral nervous system, phosphoinositide-interacting regulator of transient receptor potential channels (Pirt)-GCaMP3 (genetically encoded calcium sensor) mice were treated with EA acupuncture points, ST-36 and LIV-3, and GV-14 and Bai-hui and resulted in a rapid activation of primary sensory neurons. EA activated sensory ganglia and SNS centers to mediate the release of MSC that can enhance tissue repair, increase anti-inflammatory cytokine production and provide pronounced analgesic relief.Item Elevated Mechanical Loading When Young Provides Lifelong Benefits to Cortical Bone Properties in Female Rats Independent of a Surgically Induced Menopause(2013-09) Warden, Stuart J.; Galley, Matthew R.; Hurd, Andrea L.; Wallace, Joseph M.; Gallant, Maxime A.; Richard, Jeffrey S.; George, Lydia A.Exercise that mechanically loads the skeleton is advocated when young to enhance lifelong bone health. Whether the skeletal benefits of elevated loading when young persist into adulthood and after menopause are important questions. This study investigated the influence of a surgically induced menopause in female Sprague-Dawley rats on the lifelong maintenance of the cortical bone benefits of skeletal loading when young. Animals had their right forearm extrinsically loaded 3 d/wk between 4 and 10 weeks of age using the forearm axial compression loading model. Left forearms were internal controls and not loaded. Animals were subsequently detrained (restricted to cage activities) for 94 weeks (until age 2 years), with ovariectomy (OVX) or sham-OVX surgery being performed at 24 weeks of age. Loading enhanced midshaft ulna cortical bone mass, structure, and estimated strength. These benefits persisted lifelong and contributed to loaded ulnas having greater strength after detraining. Loading also had effects on cortical bone quality. The benefits of loading when young were not influenced by a surgically induced menopause because there were no interactions between loading and surgery. However, OVX had independent effects on cortical bone mass, structure, and estimated strength at early postsurgery time points (up to age 58 weeks) and bone quality measures. These data indicate skeletal loading when young had lifelong benefits on cortical bone properties that persisted independent of a surgically induced menopause. This suggests that skeletal loading associated with exercise when young may provide lifelong antifracture benefits by priming the skeleton to offset the cortical bone changes associated with aging and menopause.