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Squats recruit a large proportion of the body’s muscular system and provide the foundation for strength training programs for athletes. However, our understanding of electromyographical activity in variations of the high-bar back-squat, notably the split squat, is somehow limited. Therefore, this study aims to investigate surface electromyography (sEMG) activity in the free, Smith and split types of squat. A randomised sample of 10 healthy strength-trained males (age, 20.3 ± 0.5 years; height, 1.7 ± 0.6 m; mass, 78.1 ± 9.5 kg) performed 3 repetitions of each type of squat at 75% of their 1RM. A Noraxon EMG - Raxon system was used to collect peak EMG, RMS EMG, and iEMG for the eccentric and concentric phases of the squat. All sEMG data was normalised to the Smith squat. Two-way ANOVAs were used for type-of-squat and phase-of-squat (p ≤ 0.01). Statistically significant effects for type-of-squat were found for peak EMG and iEMG of the bicep femoris (BF), lateral gastrocnemius (LG) and tibialis anterior (TA) (0.001 ≤ p ≤ 0.003). Significant differences in phase-of-squat were found for peak EMG and RMS EMG of BF (p = 0.001). RMS EMG of the BF (p = 0.002) and LG (p = 0.001) showed significant differences regarding type-of-squat. Therefore, the split squat elicited higher BF and LG muscle activity compared to the free and Smith squats. The findings suggest that the split squat optimally stimulates the BF and LG and should consequently be incorporated into strength and conditioning programs for athletes.

Introduction: Inconclusive previous research on squat depth and the evoked electromyography (EMG) activity muddles our understanding of muscle recruitment in the back squat. This study determined EMG activity as a function of squat depth in four superficial muscles of the lower limb using relative loading. Method: Eight resistance trained males (mean ± SD age: 21 ± 1 years) performed back squats to partial, parallel and full depth using depth-relative 5-repetition–maximum loads. Muscle activity in the vastus medialis oblique (VMO), vastus lateralis (VL), gluteus maximus (GM), and biceps femoris (BF) during the concentric and eccentric phases of the squat was determined using surface electromyography. Peak (Peak EMG), mean (Mean EMG), and integrated (iEMG) EMG normalised to their respective maximum voluntary isometric contraction (MVIC) for each muscle were evaluated. Results: Three-way Anovas and Sidak post-hoc analysis revealed significant effects for squat type (p = 0.021 - 0.001), squat phase (p = 0.001), and muscle (p = 0.001). The significant differences were between the partial and the parallel squat (p = 0.016 - 0.001); for iEMG significant effects were also found between the partial and full squat (p = 0.001). The VMO elicited the highest EMG activity (e.g., Peak EMG 93.4 ± 36.9% MVIC; parallel squat, concentric) and the BF the lowest (e.g., Peak EMG 49.9 ± 14.7%). Greater GM activity occurred in parallel squats compared to full squats (mean difference in Peak EMG = 9.1% MVIC). Conclusion: The findings suggest that squatting to the parallel position or lower educes optimal contractile stimulation of the quadriceps. Squatting to parallel depth maximises EMG activation of the GM, possibly due to a more advantageous external moment arm or a reduction in neural drive.

Stream restoration efforts in the United States are increasingly aimed towards water quality improvement, yet little process-based guidance exists to compare pollutant removals from different restoration techniques for variable site conditions. Excess nitrate (NO₃⁻) is a frequent pollutant of concern due to eutrophication in downstream water bodies such as the Chesapeake Bay. We used MIKE SHE to simulate hydraulics and NO₃⁻ removal in a 90 m restored reach of Stroubles Creek, a second-order stream in Blacksburg, Virginia. Site specific geomorphic, hydrologic, and hydraulic data were used to calibrate the model. We evaluated in-stream structures that induce hyporheic zone denitrification during base flow and in set floodplains that remove NO₃⁻during storm flows. We varied hydraulic conditions (winter base flow, summer base flow, storm flow), biogeochemical parameters (literature hyporheic zone denitrification rates and newly available inset floodplain removal rates) and boundary conditions (upstream NO₃⁻concentration), sediment conditions (hydraulic conductivity), and stream restoration design parameters(inset floodplain length). Our results indicate that NO₃⁻removal rates within the 90 m reach were minimal. Structure-induced hyporheic zone denitrification did not exceed 3.1% of mass flowing in from the upstream channel, was achieved only during favorable background groundwater hydraulic conditions (i.e. summer base flow), and was transport-limited such that non-trivial removal rates were achieved only when the stream bed hydraulic conductivity (K) was at least 10⁻⁴m/s. Inset floodplain nitrogen removal was limited by floodplain residence time and NO₃⁻ removal rate, and did not exceed 1% of in flowing mass. Summing these removals for both restoration practices over the course of the year based on the frequency of storm and summer base flow conditions yielded ∼2.1% annual removal. Achieving 30% NO₃⁻ removal required increasing the length of stream reach restored to 0.

Stream restoration efforts in the United States are increasingly aimed towards water quality improvement, yet little process-based guidance exists to compare pollutant removals from different restoration techniques for variable site conditions. Excess nitrate (NO₃⁻) is a frequent pollutant of concern due to eutrophication in downstream water bodies such as the Chesapeake Bay. We used MIKE SHE to simulate hydraulics and NO₃⁻ removal in a 90 m restored reach of Stroubles Creek, a second-order stream in Blacksburg, Virginia. Site specific geomorphic, hydrologic, and hydraulic data were used to calibrate the model. We evaluated in-stream structures that induce hyporheic zone denitrification during base flow and in set floodplains that remove NO₃⁻during storm flows. We varied hydraulic conditions (winter base flow, summer base flow, storm flow), biogeochemical parameters (literature hyporheic zone denitrification rates and newly available inset floodplain removal rates) and boundary conditions (upstream NO₃⁻concentration), sediment conditions (hydraulic conductivity), and stream restoration design parameters(inset floodplain length). Our results indicate that NO₃⁻removal rates within the 90 m reach were minimal. Structure-induced hyporheic zone denitrification did not exceed 3.1% of mass flowing in from the upstream channel, was achieved only during favorable background groundwater hydraulic conditions (i.e. summer base flow), and was transport-limited such that non-trivial removal rates were achieved only when the stream bed hydraulic conductivity (K) was at least 10⁻⁴m/s. Inset floodplain nitrogen removal was limited by floodplain residence time and NO₃⁻ removal rate, and did not exceed 1% of in flowing mass. Summing these removals for both restoration practices over the course of the year based on the frequency of storm and summer base flow conditions yielded ∼2.1% annual removal. Achieving 30% NO₃⁻ removal required increasing the length of stream reach restored to 0.

The purpose of Friends of Marshall Public Library Oral History Project is to gather and preserve historical events and memories of the Marshall, Illinois area residents through recordings, interviews, and photos. Oral History interviews were conducted by Friends of the Library volunteers, community volunteers, and library staff.

Contains table of contents for Section 3, an introduction and reports on seven research projects., National Institutes of Health Grant P01-DC-00119, National Institutes of Health Grant R01-DC-00194, National Institutes of Health Grant R01 DC00238, National Institutes of Health Grant R01-DC02258, National Institutes of Health Grant T32-DC00038, National Institutes of Health Grant P01-DC00361, National Institutes of Health Grant 2RO1 DC00235, National Institutes of Health Contract N01-DC22402