Comparison of Clinician Assisted versus Unassisted PNF Stretching on Hamstring Flexibility, Isometric Force Output, and Maximum Vertical Jump Height

Introduction: Hamstring strains are among one of the most common acute injuries that occur in soccer players. Previous research has shown that reduced hamstring flexibility is a risk factor for injury, however this is modifiable through stretching. Some stretching techniques have contributed to decreased performance on measures important to success in sport. Proprioceptive neuromuscular facilitation (PNF) is one effective stretching technique to improve hamstring flexibility, but requires a trained partner or clinician to perform properly. It is unknown if the performance of PNF stretching without a clinician’s assistance could be as effective. It is also unknown if PNF stretching affects soccer related performance outcomes of force output and vertical jump height. Objective: To determine the effects of clinician assisted versus unassisted contract-relax PNF stretching on hamstring flexibility, maximum voluntary isometric contraction (MVIC) of the hamstring muscle group, and athletic performance via vertical jump height. Design: Controlled laboratory study. Participants: A sample of twenty-six physically active male and female college students with restricted hamstring flexibility, defined as limited passive hip flexion range of motion with the leg straight (\u3c90 degrees), participated in this study. Procedures: Subjects were randomly allocated to one of three groups; the clinician assisted, unassisted, or control groups following confirmation of inclusion criteria. The control group completed pre- and post- test measures only. The intervention groups completed a 6-week stretching intervention (12 total sessions) either with the assistance of a clinician or utilizing a stretching strap. Pre- and Post- intervention measurements were recorded for all outcome variables. Main Outcome Measures: Hip flexion range of motion was measured passively with the knee extended. Hamstring MVIC was assessed using a handheld dynamometer and normalized to each participant’s body mass. Maximal vertical jump height was measured using a Vertec. Three trials were recorded for each measure and the arithmetic mean was used to calculate change scores (Post – Pre). Change scores were utilized for data analysis. Separate one-way ANOVA’s were performed to identify differences between groups in the magnitude of change. Results: The one-way ANOVA for hip flexion ROM change scores was significant (F (2, 25) = 9.853, p = 0.001), indicating there were significant differences in the amount of change in ROM when compared across groups. Post-hoc comparisons found both the Unassisted (10.26° ± 6.03, p = 0.002) and Assisted (10.27° ± 3.81, p = 0.004) PNF intervention groups had a greater improvement in ROM compared to the Control group (-0.41° ± 7.00). There were no differences between the amount of change in the Unassisted group compared to the Assisted group. The one-way ANOVA found no significant changes in MVIC (F (2, 25) = 2.542, p = 0.101), and vertical jump height (F (2, 25) = 0.133, p = 0.877). Conclusion: Both the Assisted and Unassisted PNF stretching techniques were successful in improving hamstring flexibility. Performance measures were not impacted by the stretching intervention. Teaching a patient to perform the contract-relax PNF stretching technique to target hamstring flexibility is as effective as the clinician providing the assistance. These results may provide time saving benefits to clinicians while promoting improved flexibility and independence in patients

T. M. Lockhart to James Meredith (Undated)

https://egrove.olemiss.edu/mercorr_pro/1629/thumbnail.jp

Deformations of calibrated subbundles of Euclidean spaces via twisting by special sections

We extend the "bundle constructions" of calibrated submanifolds, due to Harvey--Lawson in the special Lagrangian case, and to Ionel--Karigiannis--Min-Oo in the cases of exceptional calibrations, by "twisting" the bundles by a special (harmonic, holomorphic, parallel) section of a complementary bundle. The existence of such deformations shows that the moduli space of calibrated deformations of these "calibrated subbundles" includes deformations which destroy the linear structure of the fibre.Comment: 16 pages, no figures. Version 2: Only minor cosmetic and typographical revisions. To appear in "Annals of Global Analysis and Geometry.

Investigation into the Functional Mobility Difference between Obese and Non-Obese Elderly

Obese aging population is increasing in the United States, and obese elderly experience fall twice as frequent as their lean counterparts. However, the mechanisms of older obese adults fall are still not clear. It is not known whether the obese elderly has more functional mobility impairments than their lean counterparts, and consequently have increased risks of falls. It was hypothesized that obese elderly have more functional mobility impairments compared with their healthy weight counterparts. Six lean and six obese community-dwelling elderly participated in the study. “Timed up & go” test was used to quantify the functional mobility for both lean and obese elderly. Stopwatch and custom-made inertial measurement units were used to obtain the temporal and kinematic parameters. The results showed that there is no significant difference in overall time to complete the “timed up & go” task, but significant difference in anterior posterior acceleration, time to reach the peak extension angular velocity from initiation and double support time between lean and obese groups of participants. Therefore, we concluded that older obese adults have some functional mobility impairments compared with their lean counterparts but the completion time of the “timed up & go” test may not be able to differentiate these individuals. Our results also suggested that obese elderly might have more muscular impairments than their healthy weight counterparts, which can result in higher fall risks. Future studies are warranted to investigate the mechanisms of increased fall risks among obese elderly

Quilted Floer Cohomology

We generalize Lagrangian Floer cohomology to sequences of Lagrangian correspondences. For sequences related by the geometric composition of Lagrangian correspondences we establish an isomorphism of the Floer cohomologies. We give applications to calculations of Floer cohomology, displaceability of Lagrangian correspondences, and transfer of displaceability under geometric composition.Comment: minor corrections and updated reference

Feasibility study of the solar scientific instruments for Spacelab/Orbiter

The feasibility and economics of mounting and operating a set of solar scientific instruments in the backup Skylab Apollo Telescope Mount (ATM) hardware was evaluated. The instruments used as the study test payload and integrated into the ATM were: the Solar EUV Telescope/Spectrometer; the Solar Active Region Observing Telescope; and the Lyman Alpha White Light Coronagraph. The backup ATM hardware consists of a central cruciform structure, called the "SPAR', a "Sun End Canister' and a "Multiple Docking Adapter End Canister'. Basically, the ATM hardware and software provides a structural interface for the instruments; a closely controlled thermal environment; and a very accurate attitude and pointing control capability. The hardware is an identical set to the hardware that flow on Skylab

Considerations for partnering with Ryan White Case Managers to create equitable opportunities for people with HIV to participate in research

Many research studies focus on recruitment from one or few HIV clinics or internet-engaged populations, but this may result in inequitable representation of people with HIV (PWH), across the rural/urban/suburban continuum. Ryan White Case Managers (RWCM) meet regularly with PWH, potentially positioning them as partners in gathering research-related data from diverse groups of low-income, marginalized, PWH. Yet, data collection in partnership with RWCM, particularly over large geographic areas, has been under-explored. We partnered with RWCM and their organizations throughout Florida to administer a 10-item technology use and willingness survey to clients living with HIV; RWCMs provided process-oriented feedback. Among 382 approached RWCM, 71% completed human subjects and survey administration training; 48% gathered data on 10 predetermined survey administration days; and 68% administered at least one survey during the entire period for survey administration. Altogether, 1,268 client surveys were completed, 2.7% by rural participants. Stigma, privacy concerns, and disinterest reportedly inhibited client participation; competing obligations, policies, and narrow recruitment windows prevented some RWCM from offering the survey to clients. Research should further explore strategies and best practices to ensure equitable access to participate in research among PWH

Design Research Units and Small to Medium Enterprises (SMEs): An Approach for Advancing Technology and Competitive Strength in Australia

© 2018 Informa UK Limited, trading as Taylor & Francis Group. This paper makes the case that small to medium enterprises (SMEs) in the manufacturing sector have the potential to benefit from connections with design research units operating within universities. It points out some of the challenges associated with research and development for SMEs, and argues design research units can allow SMEs to better meet these challenges. Additive Manufacturing is used as an exemplary emerging technology that makes explicit the new possibilities and instability of the contemporary manufacturing landscape. A case study is used to articulate the potentials and limitations of industry and university partnerships in design. In conclusion, two alternative models are analysed in order to highlight different ends to which the practitioner-based research can be put

Asymptotically cylindrical 7-manifolds of holonomy G_2 with applications to compact irreducible G_2-manifolds

We construct examples of exponentially asymptotically cylindrical Riemannian 7-manifolds with holonomy group equal to G_2. To our knowledge, these are the first such examples. We also obtain exponentially asymptotically cylindrical coassociative calibrated submanifolds. Finally, we apply our results to show that one of the compact G_2-manifolds constructed by Joyce by desingularisation of a flat orbifold T^7/\Gamma can be deformed to one of the compact G_2-manifolds obtainable as a generalized connected sum of two exponentially asymptotically cylindrical SU(3)-manifolds via the method given by the first author (math.DG/0012189).Comment: 36 pages; v2: corrected trivial typos; v3: some arguments corrected and improved; v4: a number of improvements on presentation, paritularly in sections 4 and 6, including an added picture