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BACKGROUND AND OBJECTIVES: Research on preparedness for independent clinical practice typically uses surveys of residents and program directors near graduation, which can be affected by several biases. We developed a novel approach to assess new graduates more objectively using physician and staff member assessors 3 months after graduates started their first job. METHODS: We conducted a literature review and key informant interviews with physicians from varying practice types and geographic regions in the United States to identify features that indicate a lack of preparedness for independent clinical practice. We then held a Clinical Preparedness Measurement Summit, engaging measurement experts and family medicine education leaders, to build consensus on key indicators of readiness for independent clinical practice and survey development strategies. The 2015 entrustable professional activities for family medicine end-of-residency training provided the framework for assessment of clinical preparedness by physician assessors. Sixteen published variables assessing interpersonal communication skills and processes of care delivery were identified for staff assessors. We assessed frequencies and compared survey findings between physician and staff assessors in 2016 to assist with survey validation. RESULTS: The assessment of frequencies demonstrated a range of responses, supporting the instrument's ability to distinguish readiness for independent practice of recent graduate hires. No statistical differences occurred between the physician and staff assessors for the same physician they were evaluating, indicating internal consistency. CONCLUSIONS: To learn about the possible impact of length of training, we developed a novel approach to assess preparedness for independent clinical practice of family medicine residency graduates.
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Internato e Residência , Medicina , Médicos , Humanos , Estados Unidos , Inquéritos e Questionários , Atenção à Saúde , Competência ClínicaRESUMO
The concept of anomalous self-experience, also termed Self-Disorder, has attracted both clinical and research interest, as empirical studies suggest such experiences specifically aggregate in and are a core feature of schizophrenia spectrum disorders. A comprehensive neurophenomenological understanding of Self-Disorder may improve diagnostic and therapeutic practice. This systematic review aims to evaluate anatomical, physiological, and neurocognitive correlates of Self-Disorder (SD), considered a core feature of Schizophrenia Spectrum Disorders (SSDs), towards developing a neurophenomenological understanding. A search of the PubMed database retrieved 285 articles, which were evaluated for inclusion using PRISMA guidelines. Non-experimental studies, studies with no validated measure of Self-Disorder, or those with no physiological variable were excluded. In total, 21 articles were included in the review. Findings may be interpreted in the context of triple-network theory and support a core dysfunction of signal integration within two anatomical components of the Salience Network (SN), the anterior insula and dorsal anterior cingulate cortex, which may mediate connectivity across both the Default Mode Network (DMN) and Fronto-Parietal Network (FPN). We propose a theoretical Triple-Network Model of Self-Disorder characterized by increased connectivity between the Salience Network (SN) and the DMN, increased connectivity between the SN and FPN, decreased connectivity between the DMN and FPN, and increased connectivity within both the DMN and FPN. We go on to describe translational opportunities for clinical practice and provide suggestions for future research.
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BACKGROUND AND OBJECTIVE: Survey response rates of 70% or higher are needed if findings are to be considered generalizable. Unfortunately, survey studies of health professionals have declining response rates. We have conducted survey research with residents and residency directors for over 13 years. Here we describe the strategies we used to obtain optimal response rates in residency training research collaboratives. METHODS: We administered over 6,000 surveys between 2007 and 2019 to evaluate the Preparing the Personal Physician for Practice and Length of Training Pilot studies, both of which involved redesigning residency training. Survey recipients included program directors, clinic managers, residents, graduates, as well as supervising physicians and clinic staff members. We logged and analyzed survey administration efforts and approaches to optimize strategies. RESULTS: Overall, we obtained response rates of 100% for program director surveys, 98% for resident surveys, 97% for continuity clinic surveys, 81% for graduates surveys, and 48% for the supervising physician and 43% for the clinic staff. Response rates were highest when the relationships between the evaluation team and survey recipients were closest. Strategies for optimizing response rates included (1) building relationships with all participants whenever possible, (2) sensitivity to survey timing and fatigue, and (3) using creative and persistent follow-up measures to encourage survey completion. CONCLUSION: High response rates are achievable, though they require an investment in time, resources, and ingenuity in connecting with study populations. Investigators conducting survey research must consider administrative efforts needed to achieve target response rates, including planning for funds accordingly.
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Educação de Pós-Graduação em Medicina , Internato e Residência , Humanos , Instituições de Assistência Ambulatorial , Fadiga , Pessoal de SaúdeRESUMO
Exercise with reduced muscle mass facilitates greater muscle-specific adaptations than training with larger muscle mass. The smaller active muscle mass can demand a greater portion of cardiac output which allows muscle(s) to perform greater work and subsequently elicit robust physiological adaptations that improve health and fitness. One reduced active muscle mass exercise that can promote greater positive physiological adaptations is single-leg cycling (SLC). Specifically, SLC confines the cycling exercise to a smaller muscle mass resulting in greater limb specific blood flow (i.e., blood flow is no longer "shared" by both legs) which allows the individual to exercise at a greater limb specific intensity or for a longer duration. Numerous reports describing the use of SLC have established cardiovascular and/or metabolic benefits of this exercise modality for healthy adults, athletes, and individuals living with chronic diseases. SLC has served as a valuable research tool for understanding central and peripheral factors to phenomena such as oxygen uptake and exercise tolerance (i.e., VÌO2peak and VÌO2 slow component). Together, these examples highlight the breadth of applications of SLC to promote, maintain, and study health. Accordingly, the purpose of this review was to describe: 1) acute physiological responses to SLC, 2) long-term adaptations to SLC in populations ranging from endurance athletes to middle aged adults, to individuals living with chronic disease (COPD, heart failure, organ transplant), and 3) various methods utilized to safely perform SLC. A discussion is also included on clinical application and exercise prescription of SLC for the maintenance and/or improvement of health.
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BACKGROUND AND OBJECTIVES: Training models in the Length of Training Pilot (LOTP) vary. How innovations in training length affect patient visits and resident perceptions of continuity is unknown. METHODS: We analyzed resident in-person patient encounters (2013-2014 through 2018-2019) for each postgraduate year (PGY) and total visits at graduation derived from the Accreditation Council for Graduate Medical Education reports for each LOTP program. We collected data on residents' perceptions of continuity from annual surveys (2015-2019). We analyzed continuous variables using independent samples t tests with unequal variance and categorical variables using χ2 tests in comparing 3-year (3YR) versus 4-year (4YR) programs. RESULTS: PGY-1 and PGY-2 residents in 4YR programs saw statistically more patients than their counterparts in 3YR programs. In PGY3, 3YR program residents had statistically higher visit volume compared to 4YR program residents. Visits conducted in PGY4 ranged from 832 to 884. The additional year of training resulted in approximately 1,000 more total patient visits. Most residents in 3YR and 4YR programs rated their continuity clinic experience as somewhat or very adequate (range 86.3% to 93.7%), which did not statistically differ according to length of training. CONCLUSIONS: Resident visits were significantly different at each PGY level when comparing 3YR and 4YR programs in the LOTP and the additional year of training resulted in about 1,000 more total visits. Resident perspectives on the adequacy of their continuity clinic experience appeared to not be affected by length of training. Future research should explore how the volume of patient visits performed in residency affects scope of practice and clinical preparedness.
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Medicina de Família e Comunidade , Internato e Residência , Humanos , Medicina de Família e Comunidade/educação , Educação de Pós-Graduação em Medicina/métodos , Inquéritos e Questionários , Competência ClínicaRESUMO
BACKGROUND AND OBJECTIVE: The associations between training length and clinical knowledge are unknown. We compared family medicine in-training examination (ITE) scores among residents who trained in 3- versus 4-year programs and to national averages over time. METHODS: In this prospective case-control study, we compared the ITE scores of 318 consenting residents in 3-year programs to 243 who completed 4 years of training between 2013 through 2019. We obtained scores from the American Board of Family Medicine. The primary analyses involved comparing scores within each academic year according to length of training. We used multivariable linear mixed effects regression models adjusted for covariates. We performed simulation models to predict ITE scores after 4 years of training among residents who underwent only 3 years of training. RESULTS: At baseline postgraduate year-1 (PGY1), the estimated mean ITE scores were 408.5 for 4-year programs and 386.5 for 3-year programs, a 21.9 point difference (95% CI=10.1-33.8). At PGY2 and PGY3, 4-year programs scored 15.0 points higher and 15.6 points higher, respectively. When extrapolating an estimated mean ITE score for 3-year programs, 4-year programs would still score 29.4 points higher (95% CI=15.0-43.8). Our trend analysis revealed those in 4-year programs had a slightly lesser slope increase compared to 3-year programs in the first 2 years. Their drop-off in ITE scores is less steep in later years, though these differences were not statistically significant. CONCLUSIONS: While we found significantly higher absolute ITE scores in 4 versus 3-year programs, these increases in PGY2, PGY3 and PGY4 may be due to initial differences in PGY1 scores. Additional research is needed to support a decision to change the length of family medicine training.
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Avaliação Educacional , Internato e Residência , Humanos , Estados Unidos , Projetos Piloto , Medicina de Família e Comunidade/educação , Estudos de Casos e Controles , Competência ClínicaRESUMO
Pedal speed and mechanical power output account for 99% of metabolic cost during submaximal cycling. Noncircular chainrings can alter instantaneous crank angular velocity and thereby pedal speed. Reducing pedal speed during the portion of the cycle in which most power is produced could reduce metabolic cost and increase metabolic efficiency. PURPOSE: To determine the separate contributions of pedal speed and chainring shape/eccentricity to the metabolic cost of producing power and evaluate joint-specific kinematics and kinetics during submaximal cycling across 3 chainring eccentricities (CON = 1.0; LOW = 1.13; HIGH = 1.24). METHODS: Eight cyclists performed submaximal cycling at power outputs eliciting 30%, 60%, and 90% of their individual lactate threshold at pedaling rates of 80 rpm under each chainring condition (CON80rpm; LOW80rpm; HIGH80rpm) and at pedaling rates for the CON chainring chosen to match pedal speeds of the noncircular chainrings (CON78rpm to LOW80rpm; CON75rpm to HIGH80rpm). Physiological measures, metabolic cost, and gross efficiency were determined by indirect calorimetry. Pedal and joint-specific powers were determined using pedal forces and limb kinematics. RESULTS: Physiological and metabolic measures were not influenced by eccentricity and pedal speed (all Ps > .05). Angular velocities produced during knee and hip extension were lower with the HIGH80rpm condition compared with the CON80rpm condition (all Ps < .05), while angular velocity produced during ankle plantar flexion remained unchanged. CONCLUSIONS: Despite the noncircular chainrings imposing their eccentricity on joint angular kinematics, they did not reduce metabolic cost or increase gross efficiency. Our results suggest that noncircular chainrings neither improve nor compromise submaximal cycling performance in trained cyclists.
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Articulação do Tornozelo , Ciclismo , Articulação do Tornozelo/fisiologia , Ciclismo/fisiologia , Fenômenos Biomecânicos , Humanos , Articulação do Joelho/fisiologia , Ácido LácticoRESUMO
Muscle design constraints preclude simultaneous specialization of the vertebrate locomotor system for explosive and economical force generation. The resulting performance trade-off between power and economy has been attributed primarily to individual differences in muscle fiber type composition. While certainly crucial for performance specialization, fiber type likely interacts with muscle architectural parameters, such as fascicle length, to produce this trade-off. Longer fascicles composed of more serial sarcomeres can achieve faster shortening velocities, allowing for greater power production. Long fascicles likely reduce economy, however, because more energy-consuming contractile units are activated for a given force production. We hypothesized that longer fascicles are associated with both increased power production and locomotor cost. In 11 power-trained and 13 endurance-trained recreational athletes, we measured (1) muscle fascicle length via ultrasound in the gastrocnemius lateralis, gastrocnemius medialis and vastus lateralis, (2) maximal power during cycling and countermovement jumps, and (3) running cost of transport. We estimated muscle fiber type non-invasively based on the pedaling rate at which maximal cycling power occurred. As predicted, longer gastrocnemius muscle fascicles were correlated with greater lower-body power production and cost of transport. Multiple regression analyses revealed that variability in maximal power was explained by fiber type (46% for cycling, 24% for jumping) and average fascicle length (20% for cycling, 13% for jumping), while average fascicle length accounted for 15% of the variation in cost of transport. These results suggest that, at least for certain muscles, fascicle length plays an important role in the power versus economy performance trade-off.
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Músculo Esquelético , Corrida , Fenômenos Biomecânicos , Humanos , Contração Muscular , Músculo Esquelético/diagnóstico por imagem , Músculo Quadríceps , UltrassonografiaRESUMO
Maximal muscular power production is of fundamental importance to human functional capacity and feats of performance. Here, we present a synthesis of literature pertaining to physiological systems that limit maximal muscular power during cyclic actions characteristic of locomotor behaviours, and how they adapt to training. Maximal, cyclic muscular power is known to be the main determinant of sprint cycling performance, and therefore we present this synthesis in the context of sprint cycling. Cyclical power is interactively constrained by force-velocity properties (i.e. maximum force and maximum shortening velocity), activation-relaxation kinetics and muscle coordination across the continuum of cycle frequencies, with the relative influence of each factor being frequency dependent. Muscle cross-sectional area and fibre composition appear to be the most prominent properties influencing maximal muscular power and the power-frequency relationship. Due to the role of muscle fibre composition in determining maximum shortening velocity and activation-relaxation kinetics, it remains unclear how improvable these properties are with training. Increases in maximal muscular power may therefore arise primarily from improvements in maximum force production and neuromuscular coordination via appropriate training. Because maximal efforts may need to be sustained for ~15-60 s within sprint cycling competition, the ability to attenuate fatigue-related power loss is also critical to performance. Within this context, the fatigued state is characterised by impairments in force-velocity properties and activation-relaxation kinetics. A suppression and leftward shift of the power-frequency relationship is subsequently observed. It is not clear if rates of power loss can be improved with training, even in the presence adaptations associated with fatigue-resistance. Increasing maximum power may be most efficacious for improving sustained power during brief maximal efforts, although the inclusion of sprint interval training likely remains beneficial. Therefore, evidence from sprint cycling indicates that brief maximal muscular power production under cyclical conditions can be readily improved via appropriate training, with direct implications for sprint cycling as well as other athletic and health-related pursuits.
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BACKGROUND AND OBJECTIVES: The feasibility of funding an additional year of residency training is unknown, as are perspectives of residents regarding related financial considerations. We examined these issues in the Family Medicine Length of Training Pilot. METHODS: Between 2013 and 2019, we collected data on matched 3-year and 4-year programs using annual surveys, focus groups, and in-person and telephone interviews. We analyzed survey quantitative data using descriptive statistics, independent samples t test, Fisher's Exact Test and χ2. Qualitative analyses involved identifying emergent themes, defining them and presenting exemplars. RESULTS: Postgraduate year (PGY)-4 residents in 4-year programs were more likely to moonlight to supplement their resident salaries compared to PGY-3 residents in three-year programs (41.6% vs 23.0%; P=.002), though their student debt load was similar. We found no differences in enrollment in loan repayment programs or pretax income. Programs' descriptions of financing a fourth year as reported by the program director were limited and budget numbers could not be obtained. However, programs that required a fourth year typically reported extensive planning to determine how to fund the additional year. Programs with an optional fourth year were budget neutral because few residents chose to undertake an additional year of training. Resources needed for a required fourth year included resident salaries for the fourth year, one additional faculty, and one staff member to assist with more complex scheduling. Residents' concerns about financial issues varied widely. CONCLUSIONS: Adding a fourth year of training was financially feasible but details are local and programs could not be compared directly. For programs that had a required rather than optional fourth year much more financial planning was needed.
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Internato e Residência , Educação de Pós-Graduação em Medicina , Medicina de Família e Comunidade/educação , Humanos , Projetos Piloto , Inquéritos e QuestionáriosRESUMO
Cycling technique is steeped in cultural lore. One deeply held belief is that "pulling up" to lift the leg (increased muscular leg flexion) will optimize technique and improve efficiency. In contrast, scientific evidence suggests that when cyclists are instructed to pull-up efficiency decreases. However, such interventions may not have allowed sufficient time for cyclists to adapt and refine their technique. This case study documented how a cyclist with a complete unilateral limb amputation consumed metabolic power to produce mechanical power during single-leg cycling. The cyclist was a four time US National Paralympic Champion who performed single-leg cycling for 7 yr and thus was fully adapted to pull up. We hypothesized that a counterweight system, which reduced the requirement to pull up, would decrease metabolic power and increase efficiency for this cyclist. The cyclist performed submaximal cycling (100, 135, 170, 205 W, 80 rpm, 5 min) with and without a counterweight (10 kg) on the unused crank. Expired gases were measured, and metabolic power and gross efficiency were calculated. Metabolic power decreased on average by 87 ± 7 W (P < 0.001) and gross efficiency increased from 16.3 ± 1.9 to 18.0 ± 1.8% (P < 0.001) when cycling with the counterweight. During counterweighted single-leg cycling, the metabolic power of unloaded cycling decreased (317 vs. 238 W) and delta efficiency was similar (25.2 vs. 25.5%). Results demonstrated that significant metabolic power was associated with pulling up to produce muscular leg flexion power even in a cyclist who pulled up substantially during cycling. Our findings confirm observations from previous studies that altered pedaling technique acutely and indicate that pulling up during cycling is less efficient.NEW & NOTEWORTHY This study offers unique insight into pedaling technique and provides the "final nail in the coffin" to the notion that pulling up improves cycling efficiency. When the requirement for pulling up was reduced with the counterweight, the cyclist immediately benefited as the cost to move the limb decreased and gross efficiency increased. These case study results along with previous research suggest that, in general, cyclists should not adopt pedaling techniques, which increase the action of pulling up.
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Amputados , Ciclismo , Humanos , Músculo Esquelético , Consumo de Oxigênio , Amplitude de Movimento ArticularRESUMO
PURPOSE: Single-leg cycling exercise is one of the most potent, but underutilized, stimuli for promoting peripheral muscle respiratory capacity. Special ergometers used to facilitate single-leg cycling, while maintaining biomechanics similar to double-leg cycling, are not widely available. This lack of availability of specialized ergometers may explain why single-leg cycling has not been widely implemented as standard clinical practice. Therefore, we explored the extent to which participants could emphasize one leg and de-emphasize the other to perform "single-leg emphasis cycling" using standard cycle ergometers. METHODS: Sixteen athletic participants performed single-leg emphasis cycling, emphasizing each leg in separate trials, and double-leg cycling. Pedal forces and limb kinematics were collected and used to calculate joint-specific work and power at the ankle, knee, and hip. RESULTS: Study participants were able to produce approximately three times as much power with their emphasized leg compared to the de-emphasized leg during single-leg emphasis cycling. Ankle plantar flexion, dorsiflexion, knee extension, and hip extension work produced during single-leg emphasis cycling did not differ from those during double-leg cycling (all P > .60). Hip and knee flexion work during single-leg emphasis cycling exhibited small but significant differences (both P < .05) from double-leg cycling. CONCLUSIONS: These results demonstrate that single-leg emphasis cycling provides a convenient alternative to single-leg cycling requiring specialized ergometers, therefore, facilitating improved training in clinical and athletic populations using commonly available equipment. Further, biomechanics during single-leg emphasis cycling closely approximated double-leg cycling ensuring that training adaptations are highly applicable to double-leg cycling.
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Atletas , Ciclismo/fisiologia , Ergometria/métodos , Perna (Membro)/fisiologia , Adulto , Fenômenos Biomecânicos , Feminino , Humanos , MasculinoRESUMO
Sexual dimorphism often arises from selection on specific musculoskeletal traits that improve male fighting performance. In humans, one common form of fighting includes using the fists as weapons. Here, we tested the hypothesis that selection on male fighting performance has led to the evolution of sexual dimorphism in the musculoskeletal system that powers striking with a fist. We compared male and female arm cranking power output, using it as a proxy for the power production component of striking with a fist. Using backward arm cranking as an unselected control, our results indicate the presence of pronounced male-biased sexual dimorphism in muscle performance for protracting the arm to propel the fist forward. We also compared overhead pulling force between males and females, to test the alternative hypothesis that sexual dimorphism in the upper body of humans is a result of selection on male overhead throwing ability. We found weaker support for this hypothesis, with less pronounced sexual dimorphism in overhead arm pulling force. The results of this study add to a set of recently identified characters indicating that sexual selection on male aggressive performance has played a role in the evolution of the human musculoskeletal system and the evolution of sexual dimorphism in hominins.
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Agressão , Braço/fisiologia , Força Muscular , Seleção Sexual , Adulto , Animais , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Caracteres Sexuais , Adulto JovemRESUMO
INTRODUCTION/PURPOSE: Muscular power is important in applications ranging from elite sport to activities of daily living. Results for improvements in power after resistance training have been mixed, possibly because of changes in muscle activation and deactivation rates. Our purpose was to determine the effects of heavy and explosive training programs on maximal power across a range of frequencies during cyclical contractions using a mathematical model. METHODS: Maximal force production and time constants for muscle activation and deactivation after heavy and explosive training programs were determined using previously reported data. A muscle-tendon model was subjected to sinusoidal length change, and activation and deactivation were set to maximize power for a range of cycle frequencies (0.5-3.0 Hz). Power for shortening/lengthening cycles was modeled for each training program and for a hypothetical periodized program with the best results from each program. RESULTS: The heavy training program increased strength by 26.8%, and increased time required for activation (20%) and deactivation (48%). The explosive training program increased strength by 10.8%, but decreased time required for activation (24%) and deactivation (10%). Increases in maximal power were similar after heavy (13.6%) and explosive (13.8%) training, but with different power-frequency relationships (optimal frequencies of 1.56 and 1.94 Hz for heavy and explosive, respectively). The hypothetical periodized program increased power by 30.3% (optimal frequency at 1.94 Hz). CONCLUSION: Power during low-frequency movements (e.g., swimming) improved more after heavy training, whereas power during high-frequency movements (e.g., running) improved more after explosive training. These findings suggest that changes in time required for activation and deactivation in response to training are highly influential for maximal power across a range of functional frequencies, ultimately altering the ideal training regimen for specific activities.
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Força Muscular/fisiologia , Treinamento Resistido/métodos , Atividades Cotidianas , Desempenho Atlético/fisiologia , Humanos , Modelos Estatísticos , Contração Muscular , Músculo Esquelético/fisiologiaRESUMO
Effects of knee alignment on the internal knee abduction moment (KAM) in walking have been widely studied. The KAM is closely associated with the development of medial knee osteoarthritis. Despite the importance of knee alignment, no studies have explored its effects on knee frontal plane biomechanics during stationary cycling. The purpose of this study was to examine the effects of knee alignment and use of a toe clip on the knee frontal plane biomechanics during stationary cycling. A total of 32 participants (11 varus, 11 neutral, and 10 valgus alignment) performed five trials in each of six cycling conditions: pedaling at 80 rpm and 0.5 kg (40 Watts), 1.0 kg (78 Watts), and 1.5 kg (117 Watts) with and without a toe clip. A motion analysis system and a customized instrumented pedal were used to collect 3D kinematic and kinetic data. A 3 × 2 × 3 (group × toe clip × workload) mixed design ANOVA was used for statistical analysis (p < 0.05). There were two different knee frontal plane loading patterns, internal abduction and adduction moment, which were affected by knee alignment type. The knee adduction angle was 12.2° greater in the varus group compared to the valgus group (p = 0.001), yet no difference was found for KAM among groups. Wearing a toe clip increased the knee adduction angle by 0.95º (p = 0.005). The findings of this study indicate that stationary cycling may be a safe exercise prescription for people with knee malalignments. In addition, using a toe clip may not have any negative effects on knee joints during stationary cycling.
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Ciclismo , Ergometria/instrumentação , Articulação do Joelho/fisiologia , Carga de Trabalho , Adulto , Fenômenos Biomecânicos , Humanos , Movimento , Dedos do Pé , Adulto JovemRESUMO
Fish, birds and lizards sometimes perform locomotor activities with maximized muscle power. Whether humans maximize muscle power is unknown because current experimental techniques cannot be applied non-invasively. This study leveraged simulated muscle work loops to examine whether voluntary maximal cycling is characterized by maximized muscle power. The simulated work loops used experimentally measured joint angles, anatomically realistic muscle parameters (muscle-tendon lengths, velocities and moment arms) and a published muscle model to calculate power and force for 38 muscles. For each muscle, stimulation onset and offset were optimized to maximize muscle work and power for the complete shortening/lengthening cycle. Simulated joint power and total leg power (i.e. summed muscle power) were compared with previously reported experimental joint and leg power. Experimental power values were closely approximated by simulated maximal power for the leg [intraclass correlation coefficient (ICC)=0.91], the hip (ICC=0.92) and the knee (ICC=0.95), but less closely for the ankle (ICC=0.74). Thus, during maximal cycling, humans maximize muscle power at the hip and knee, but the ankle acts to transfer (instead of maximize) power. Given that only the timing of muscle stimulation onset and offset were altered, these results suggest that human motor control strategies may optimize muscle activation to maximize power. The simulations also provide insight into biarticular muscle function by demonstrating that the power values at each joint spanned by a biarticular muscle can be substantially greater than the net power produced by the muscle. Our work-loop simulation technique may be useful for examining clinical deficits in muscle power production.
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Articulação do Tornozelo/fisiologia , Ciclismo/fisiologia , Articulação do Quadril/fisiologia , Articulação do Joelho/fisiologia , Contração Muscular/fisiologia , Fenômenos Biomecânicos , Feminino , Humanos , MasculinoRESUMO
Noncircular chainrings could increase cycling power by prolonging the powerful leg extension/flexion phases, and curtailing the low-power transition phases. We compared maximal cycling power-pedaling rate relationships, and joint-specific kinematics and powers across 3 chainring eccentricities (CON = 1.0; LOWecc = 1.13; HIGHecc = 1.24). Part I: Thirteen cyclists performed maximal inertial-load cycling under 3 chainring conditions. Maximum cycling power and optimal pedaling rate were determined. Part II: Ten cyclists performed maximal isokinetic cycling (120 rpm) under the same 3 chainring conditions. Pedal and joint-specific powers were determined using pedal forces and limb kinematics. Neither maximal cycling power nor optimal pedaling rate differed across chainring conditions (all p > .05). Peak ankle angular velocity for HIGHecc was less than CON (p < .05), while knee and hip angular velocities were unaffected. Self-selected ankle joint-center trajectory was more eccentric than HIGHecc with an opposite orientation that increased velocity during extension/flexion and reduced velocity during transitions. Joint-specific powers did not differ across chainring conditions, with a small increase in power absorbed during ankle dorsiflexion with HIGHecc. Multiple degrees of freedom in the leg, crank, and pedal system allowed cyclists to manipulate ankle angular velocity to maintain their preferred knee and hip actions, suggesting maximizing extension/flexion and minimizing transition phases may be counterproductive for maximal power.
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Ciclismo/fisiologia , Equipamentos Esportivos , Adulto , Articulação do Tornozelo/fisiologia , Fenômenos Biomecânicos , Feminino , Articulação do Quadril/fisiologia , Humanos , Articulação do Joelho/fisiologia , MasculinoRESUMO
BACKGROUND AND OBJECTIVES: Evolutions in care delivery toward the patient-centered medical home have influenced important aspects of care continuity. Primary responsibility for a panel of continuity patients is a foundational requirement in family medicine residencies. In this paper we characterize challenges in measuring continuity of care in residency training in this new era of primary care. METHODS: We synthesized the literature and analyzed information from key informant interviews and group discussions with residency faculty and staff to identify the challenges and possible solutions for measuring continuity of care during family medicine training. We specifically focused on measuring interpersonal continuity at the patient level, resident level, and health care team level. RESULTS: Challenges identified in accurately measuring interpersonal continuity of care during residency training include: (1) variability in empanelment approaches for all patients, (2) scheduling complexity in different types of visits, (3) variability in ability to attain continuity counts at the level of the resident, and (4) shifting make-up of health care teams, especially in residency training. Possible solutions for each challenge are presented. Philosophical issues related to continuity are discussed, including whether true continuity can be achieved during residency training and whether qualitative rather than quantitative measures of continuity are better suited to residencies. CONCLUSIONS: Measuring continuity of care in residency training is challenging but possible, though improvements in precision and assessment of the comprehensive nature of the relationships are needed. Definitions of continuity during training and the role continuity measurement plays in residency need further study.
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Competência Clínica , Continuidade da Assistência ao Paciente/normas , Medicina de Família e Comunidade/educação , Internato e Residência/normas , Relações Médico-Paciente , Agendamento de Consultas , Continuidade da Assistência ao Paciente/organização & administração , Medicina de Família e Comunidade/organização & administração , Grupos Focais , Humanos , Internato e Residência/organização & administração , Entrevistas como Assunto , Equipe de Assistência ao Paciente/organização & administração , Indicadores de Qualidade em Assistência à SaúdeRESUMO
UNLABELLED: During submaximal cycling, the neuromuscular system has the freedom to select different intermuscular coordination strategies. From both a basic science and an applied perspective, it is important to understand how the central nervous system adjusts pedaling mechanics in response to changes in pedaling conditions. PURPOSE: To determine the effect of changes in pedal speed (a marker of muscle shortening velocity) and crank length (a marker of muscle length) on pedaling mechanics during submaximal cycling. METHODS: Fifteen trained cyclists performed submaximal isokinetic cycling trials (90 rpm, 240 W) using pedal speeds of 1.41 to 1.61 m·s(-1) and crank lengths of 150 to 190 mm. Joint powers were calculated using inverse dynamics. RESULTS: Increases in pedal speed and crank length caused large increases knee and hip angular excursions and velocities (P < 0.05), whereas ankle angular kinematics stayed relatively constant (P > 0.05). Joint moments and joint powers were less affected by changes in the independent variables, but some interesting effects and trends were observed. Most noteworthy, knee extension moments and powers tended to decrease, whereas hip extension power tended to increase with an increase in crank length. CONCLUSIONS: The distribution of joint moments and powers is largely maintained across a range of pedaling conditions. The crank length induced differences in knee extension moments, and powers may represent a trade-off between the central nervous system's attempts to simultaneously minimize muscle metabolic and mechanical stresses. These results increase our understanding of the neural and mechanical mechanisms underlying multi-joint task performance, and they have practical relevance to coaches, athletes, and clinicians.