• Biomechanics of Cycling and Factors Affecting Performance

      Too, Danny; The College at Brockport (1990-01-01)
      Cycling performance in human powered vehicles is affected by the interaction of a number of variables, including environment, mechanical and human factors. Engineers have generally focused on the design and development of faster, more efficient human-powered vehicles based on minimizing aerodynamic drag, neglecting the human component, On the other hand, kinesiologists have examined cycling performance from a human perspective, but have been constrained by the structure of a standard bicycle. Therefore, a gap exists between research in the various disciplines. To maximize/optimize cycling performance in human-powered vehicles requires a bridging of this gap through interdisciplinary research. Changes in different variables can affect the energy requirements of cycling. These variables include: (a) changes in body position, configuration. and orientation; (b) changes in seat to pedal distance; and (c) the interaction of workload, power output, and pedalling rate. Changes in these variables alter joint angles, muscle lengths, and muscle moment arm lengths, thus affecting the tension-length, force-velocity-power relationships of multij-oint muscles and the effectiveness of force production. This is ultimately manifested as a change in the energetics of cycling. A large number of factors affect cycling performance in human-powered vehicles and a gap still exists between cycling research in various disciplines. To bridge this gap, if not completely close it, requires cooperation between disciplines and further interdisciplinary research.
    • Factors affecting performance in human powered vehicles: a biomechanical model

      Too, Danny; The College at Brockport (2003-04-01)
      There are a large number of biomechanical factors that affect cycling performance. These factors can often be grouped into one of three categories: (1) environmental factors, (2) internal biomechanical factors, and (3) external mechanical factors. The interaction of different factors within a category can be complex, but need to be examined and understood if more effective human-powered vehicles are to be developed. The purpose of this paper is two-fold: (1) to examine the factors in each category, their interactions, and how they affect performance in human-powered vehicles, and (2) to provide a biomechanical performance model for these factors.
    • Maximizing Performance in Human Powered Vehicles: A Literature Review and Directions for Future Research

      Too, Danny; Landwer, Gerald E.; The College at Brockport; University of Nevada, Las Vegas (2008-06-21)
      If the limits of performance in human powered vehicles (HPV) are to be reached, designers of HPVs need to understand how the body interacts with the vehicle to maximize propulsive forces, and how the vehicle interacts with the environment to minimize resistive forces. This paper will review, compare and summarize the various research literature on both upright and recumbent cycling positions regarding how systematic changes in external mechanical variables (seat-tube-angle, seat-to-pedal distance, crank arm length) interact with internal biomechanical factors (hip, knee, and ankle angles) to affect power production and cycling performance. Conclusions for future research will also be also presented.
    • Response to Questions

      Too, Danny; The College at Brockport (1998-01-01)
      Danny Too responded to some questions on aspects of his papers, and was gracious enough to allow us to publish them. Questions are shortened in several cases. -Dave Wilson
    • Summaries of Papers

      Too, Danny; The College at Brockport (1998-01-01)
      A summary of the papers published between 1990-1996 by the author in the Human Power journal.
    • The Effect of Body Configuration on Cycling Performance

      Too, Danny; The College at Brockport (1990-01-01)
      The design of human powered vehicles has focused exclusively on the aerodynamic properties of the vehicle with the cyclist. To further improve performance, it becomes necessary to focus on some aspect other than the aerodynamic properties. The most logical area to explore would be the human engine which powers the vehicles. It is then unknown as to whether improved cycling performance is attributed tn changes in hip angles, knee angles or both; and what the most effective ranges of hip and knee angles are for one pedal revolution. Therefore. the purpose of this investigation was to determine the effect of changes in hip angles on cycling performance as measured by cycling duration and total work output.
    • The Effect of Body Orientation on Cycling Performance

      Too, Danny; The College at Brockport (1989-01-01)
      The design of human-powered vehicles has focused exclusively on the aerodynamic properties of the vehicle exceeding 65 mph, it's obvious as to the importance of minimizing aerodynamic drag. But, from an energetics perspective, how a cyclist should be positioned or what body orientation should be assumed to maximize performance is unknown. Changes in body orientation will place the legs at a different angle with respect to the line of gravity, therefore affecting both the hemodynamics of blood flow and force contribution by the body weight. The effect on cycling performance and whether there may be an interaction effect between blood flow hemodynamics and body weight contribution in different body orientation is also unknown. The purpose of this investigation was to determine the effect of changes in body orientation on energy expenditure, cycling duration and total work output.
    • The Effect of Body Orientation on EMG Patterns in Cycling

      Too, Danny; The College at Brockport (1991-01-01)
      In human powered vehicles, manipulation of body orientation often results in changes in cycling performance. These changes in performance may be attributed to alterations in: (1) the aerodynamic properties of the cyclist and vehicle; (2) contribution of the lower limb weight to pedal force production; and/or (3) body configuration (joint angle changes affecting the interactions between the muscle length and moment arm length of the muscle groups involved in cycling). In a previous investigation examining cycling performance in a semi-prone, upright, and semi-recumbent position (the trunk relative to the ground at an angle of 60, 90, and 120 degrees, respectively), it had been concluded that an optimal cycling body orientation exists which maximizes power production (Too, 1991). Because the body configuration (hip, knee, and ankle angle) had been controlled for in that investigation, it had been speculated that differences in power production were attributed to changes in lower limb weight contribution to the total force on the pedals. It is believed that these differences would be reflected by changes in the muscle activity patterns. Therefore, it was the purpose of this investigation to determine whether cycling performance differences with different body orientations are attributed to changes in EMG patterns, as determined by one or more of these: (1) the sequence of activity by the different muscles; (2) the duration of the muscle activity; and (3) the pedal position each muscle was active and inactive during a complete pedal cycle.
    • The Effect of Body Position/Configuration and Orientation on Power Output

      Too, Danny; The College at Brockport (1992-08-06)
      Kinesiologists, unlike engineers, have always examined cycling performance based on a human factors perspective. But. these investigations have always been based on the constraints imposed by the structure of a conventional bicycle. These investigations have included the effects on cycling performance with changes in seat height, crank arm length, pedaling frequencies, workloads, total .workoutput, etc. Therefore, a gap exist between research in the various disciplines. To maximize/optimize cycling performance in human powered vehicles requires a bridging of this gap through interdisciplinary research. The purpose of these investigations were to determine the effect of systematic changes in: (1) body position/configuration (seat tube angle/hip angles); and (2) body orientation (trunk angle with respect to the ground) on cycling performance as defined by power output.
    • The Effect of Pedal Crank Arm Length and Seat Height on Joint Angles in an Upright Cycling Position

      Too, Danny; Williams, Christopher D.; The College at Brockport (2020-01-01)
      Manipulations in crank arm length and seat height have resulted in significant changes in cycling performance. To better understand how these manipulations affect cycling performance, the purpose of this investigation was to determine the effect of 5 pedal crank arm lengths (l10, 145, 180, 215 and 250 mm) and 3 seat height (short, medium, and long) on joint angles (minimum, maximum, and range of motion) of the hip, knee, and ankle, as determined by 3 in an upright cycling position for 7 male participants. Nine 5 x 3 Repeated Measures Factor ANOVAs revealed that 35 mm increments in crank arm length from I l0-250mm resulted in a significant (p < 0.01): (1) decrement int he minimum hip and knee angle; (2) increment in the minimum ankle angle; (3) increment in the hip and knee range of motion; and (4) decrement in the ankle range of motion. It was determined that 6 cm changes in seat height from the shortest to the longest seat height resulted in a significant (p < 0.01): (l) increment in the minimum and maximum joint angle of the hip, knee, and ankle; and (2) increment in the range of motion of the knee. No significant interactions were found between crank arm length and seat height for different angle measurements (minimum, maximum, and range of motion) of the hip, knee, and ankle. In conjunction with the results of previous investigations, certain joint angle ranges result in more effective cycling performance.