For Aging Research and Equity: Lessons Learned in Undergraduate Research Education.

Mentoring underrepresented students in aging research during the COVID-19 pandemic affords many opportunities for innovation and learning, for both students and program leaders. Here, we describe lessons learned from an Advancing Diversity in Aging Research (ADAR) program at a women-centered, minority-serving undergraduate institution. We share program elements and assessment results related to scholars' education in aging, support through community-building and mentorship, and research experiences in gerosciences. Notably, we highlight lessons learned for retaining and training undergraduate students as graduate school-ready researchers: 1) draw students into a community focused on social justice, 2) show students that geroscience is inclusive and integrative, 3) model professionalism with flexibility, 4) keep open lines of communication, and 5) build a team of mentors around each scholar. By sharing insights from our community of practice in geroscience research and education, we hope to model best practices for URM student support in aging research.

The Biomechanical and Energetic Advantages of a Mediolaterally Wide Pelvis in Women.

Here, we argue that two key shifts in thinking are required to more clearly understand the selection pressures shaping pelvis evolution in female hominins: (1) the primary locomotor mode of female hominins was loaded walking in the company of others, and (2) the periodic gait of human walking is most effectively explained as a biomechanically controlled process related to heel-strike collisions that is tuned for economy and stability by properly-timed motor inputs (a model called dynamic walking). In the light of these two frameworks, the evidence supports differences between female and male upper-pelvic morphology being the result of the unique reproductive role of female hominins, which involved moderately paced, loaded walking in groups. Anat Rec, 300:764-775, 2017. © 2017 Wiley Periodicals, Inc.

Reproductive costs for everyone: how female loads impact human mobility strategies.

While mobility strategies are considered important in understanding selection pressures on individuals, testing hypotheses of such strategies requires high resolution datasets, particularly at intersections between morphology, ecology and energetics. Here we present data on interactions between morphology and energetics in regards to the cost of walking for reproductive women and place these data into a specific ecological context of time and heat load. Frontal loads (up to 16% of body mass), as during pregnancy and child-carrying, significantly slow the optimal and preferred walking speed of women, significantly increase cost at the optimal speed, and make it significantly more costly for women to walk with other people. We further show for the first time significant changes in the curvature in the Cost of Transport curve for human walking, as driven by frontal loads. The impact of these frontal loads on females, and the populations to which they belong, would have been magnified by time constraints due to seasonal changes in day length at high latitudes and thermoregulatory limitations at low latitudes. However, wider pelves increase both stride length and speed flexibility, providing a morphological offset for load-related costs. Longer lower limbs also increase stride length. Observed differences between preferred and energetically optimal speeds with frontal loading suggest that speed choices of women carrying reproductive loads might be particularly sensitive to changes in heat load. Our findings show that female reproductive costs, particularly those related to locomotion, would have meaningfully shaped the mobility strategies of the hominin lineage, as well as modern foraging populations.

The application to bipeds of a geometric model of lower-limb-segment inertial properties.

Drawing inferences about locomotor energetics from limb morphology, especially in regard to small differences between individuals, depends critically on valid estimates of lower-limb inertial properties. While there are numerous options for such estimations in the literature, geometric models that involve simple measures and straightforward mathematics combined with the ability to capture individual variation are rare. In this research, we apply a method, originally developed for quadrupeds, that models limb segments as elliptical columns. When the elliptical model is applied to bipeds, it provides a means of estimating limb-segment inertial properties accurately enough to test differences between individuals of similar stature and mass, but with variation in mass distribution and limb length. We test the method against commonly used equations and are able to show the validity of the method for thigh and shank segments.

Hip muscle weakness and overuse injuries in recreational runners.

OBJECTIVE: To test for differences in strength of 6 muscle groups of the hip on the involved leg in recreational runners with injuries compared with the uninvolved leg and a control group of noninjured runners. DESIGN: Descriptive analysis. SETTING: : Three outpatient physical therapy clinics in the Minneapolis/St. Paul metropolitan area. PARTICIPANTS: Thirty recreational runners (17 female, 13 male) experiencing a single leg overuse injury that presented for treatment between June and September 2002. Thirty noninjured runners (16 female, 14 male) randomly selected from a pool of 46 volunteers from a distance running club served as controls. MAIN OUTCOME MEASURES: Self-report demographic information on running habits, leg dominance demonstrated by preferred kicking leg, and injury information. Muscle strength of the 6 major muscle groups of the hip was recorded using a hand-held dynamometer. The highest value of 2 trials was used, and strength values were normalized to body mass(2/3). RESULTS: Results comparing the injured and noninjured groups showed that leg dominance did not influence the leg of injury (chi(2)(1) = 0.134; P = 0.71). Correlations for internal reliability of muscle measurements between trials 1 and 2 with the hand-held dynamometer ranged from 0.80 to 0.90 for the 6 muscle groups measured, and all P values were less than 0.0001. No significant side-to-side differences in hip group muscle strength were found in the noninjured runners (P = 0.62-0.93). Among the injured runners, the injured side hip abductor (P = 0.0003) and flexor muscle groups (P = 0.026) were significantly weaker than the noninjured side. In addition, the injured side hip adductor muscle group was significantly stronger (P = 0.010) than the noninjured side. Duration of symptoms was not a contributing factor to the extent of injury as measured by muscle strength imbalance between injured and uninjured sides. CONCLUSIONS: Although no cause-and-effect relationship has been established, this is the first study to show an association between hip abductor, adductor, and flexor muscle group strength imbalance and lower extremity overuse injuries in runners. Because most running injuries are multifaceted in nature, areas secondary to the site of pain, such as hip muscle groups exhibiting strength imbalances, must also be considered to gain favorable outcomes for injured runners. The addition of strengthening exercises to specifically identified weak hip muscles may offer better treatment results in patients with running injuries.

Inquiry-based laboratory course improves students' ability to design experiments and interpret data.

We redesigned our intermediate-level organismal physiology laboratory course to center on student-designed experiments in plant and human physiology. Our primary goals were to improve the ability of students to design experiments and analyze data. We assessed these abilities at the beginning and end of the semester by giving students an evaluation tool consisting of an experimental scenario, data, and four questions of increasing complexity. To control for nontreatment influences, the improvement scores (final minus initial score for each question) of students taking both the laboratory and the companion lecture course were compared with those of students taking the lecture course only. The laboratory + lecture group improved more than the lecture-only group for the most challenging question. This evidence suggests that our inquiry-based curriculum is achieving its primary goals. The evaluation tool that we developed may be useful to others interested in measuring experimental analysis abilities in their students.