Alterations in running shoe design have been studied and used in the prevention of injury and enhancement of performance allowing running shoe companies to market to a variety of runners based on skill level, foot-strike pattern, and even sex. These alterations have been shown to affect biomechanical and physiological variables associated with running. Some shoe companies have designed shoes specifically for biological female runners due to the morphological differences found between male and female feet. The purpose of this study is to determine if sex-specific running shoes can alter female runner biomechanics or physiology. Female runners were asked to run in the male and female models of the Altra Torin 4 Plush shoe to determine if there were differences in ground reaction forces (GRFs), sagittal plane joint angles and moments, oxygen consumption (VO2), respiratory exchange ratio (RER), and perceived level of comfort while running; There were no significant differences in GRFs, sagittal joint angles and moments, VO2, RER, or perceived comfort; There were no differences in measured biomechanical or physiological variables between the female and male version of the shoes suggesting that the alterations made to the female-specific shoe do not provide any additional benefit to female recreational runners.

Overwintering monarch (Danaus plexippus) populations have declined since the 1990s. In response, restoration of milkweeds, including Asclepias syriaca (common milkweed), an important host plant in their breeding grounds, has become increasingly common. However, latitudinal variation in milkweed populations suggests the possibility of regional adaptation and the potential for seed provenance to affect restoration success. Using seeds from 20 populations throughout the range of A. syriaca, we tested whether seed mass, germination success, and germination time in the greenhouse demonstrate geographic clines consistent with available evidence for this species from other studies. In addition, we tested for patterns in germination traits consistent with adaptation to spring thermal conditions by planting seeds from 10 populations in growth chambers simulating Minnesota and Kentucky spring temperatures. Even after accounting for seed mass, seeds from higher latitudes germinated faster on average under all conditions. Elevated temperatures accelerated germination time and leaf development time; however, we did not detect geographic patterns in leaf development time, indicating that the processes underlying the latitudinal cline in germination time may be unique to the germination stage. In the thermal adaptation study, high‐latitude populations produced larger seeds and seeds that germinated at a higher rate; however, neither latitudinal trend was observed in the geographic clines study, even though individual seed mass predicted germination success. High‐latitude populations express more favorable germination traits in every setting measured, perhaps due to reduced dormancy. Consequently, we conclude that latitudinal clines are more consistent with adaptation to growing season length than to spring temperatures.

and finish phases of the stroke. PURPOSE: To compare joint angles and peak angular velocities of the knee and lumbar spine during the feet-out drill, as well as peak lumbar extension timing within the stroke, on a static (SRE) versus dynamic (DRE) rowing ergometer, as well as between sexes. METHODS: 15 experienced rowers (8 females, 22.73 ± 5.51 years) participated in this study. Using a within-subjects, repeated measures design, subjects completed 750 meters of the feet-out drill on both the SRE and DRE at 20 ± 1 strokes per minute. Seven inertial measurement units were placed on the subjects' 7th cervical spinal process, sacrum, 12th thoracic spinal process, and bilateral thigh and leg segments. Peak lumbar extension timing for ten consecutive strokes was identified as a percentage of stroke. The beginning and end of each stroke was defined by maximum knee flexion. A mixed between-within ANOVA was run to compare males and females and between ergometers. Paired t-tests were run for kinematic variables between ergometers. Pearson correlations were used for weight and height with kinematic data. RESULTS: Peak lumbar extension occurred later on the SRE (38.08 ± 5.18%) when compared to the DRE (34.60 ± 3.93%, p = .01). Likewise, females had an earlier peak lumbar extension (n = 7, DRE 32.43 ± 3.05%, SRE 35.23 ± 4.12%) compared to males (n = 6, DRE 37.13 ± 3.40%, SRE 41.40 ± 4.41%, p =.01). SRE lumbar ROM and weight had a strong correlation (r = .86, p < .01) which was not seen with the DRE. CONCLUSIONS:The ratio of the phases of the drive and finish of the rowing stroke appears to be affected during the feet-out drill on a SRE vs DRE. The DRE appears to be the more ideal choice for a stroke with less emphasis on the second half of the drive and finish phases and for limiting lumbar spine ROM in heavier athletes. Coaches and athletes should proceed with awareness of such differences when choosing to complete the drill on a dynamic or static rowing ergometer.

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