1. (A) Illustration of saddle height and saddle to handlebar height and length. (B) Lower limb measure is commonly used to configure saddle height (1-inseam length, 2-throcanteric length and 3-ischial tuberosity length). 

Contexts in source publication

Context 1

... horizontal (distance from the handlebars to the saddle) and vertical (height) positions of the handlebars affect the upper body flexion angle [10,65]. The position of the handlebars has been empirically related to the sum of lengths of the torso and the arm [10]. Usually the horizontal position of the handlebars is fixed unless the headset of the bicycle is changed. Therefore, the effects of the combined horizontal and vertical position of the handlebars will dictate the angles of the trunk and pelvis (see Figure 1.8). High rates of low back pain (up to 60%) [157] have been reported for cyclists, which may result from forward trunk flexion and pronounced lumbar kyphosis on the bicycle compared to the standing upright position [167]. Burnett et al. [157] reported no significant difference between the pelvic angle for cyclists with (15 ±5.1) and without (23 ±5.8) low back pain during fatiguing cycling with the hands on the drops of the handlebars. It is possible however that large between-subject variability in trunk and pelvic angles may hide any relationship between lower back pain and upper body position in cycling [157]. Furthermore, both saddle shape [166] and inclination angle [162] have been found to affect the angle of the pelvis which may make it difficult to isolate the relationship between trunk angle and low back ...

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... gather a full picture of the biomechanics of cycling, it is important to determine all forces action on the cyclist-bicycle during pedaling. Given cyclists produce force in their muscles and transfer that through the skeletal system to the pedals, pedal forces are critical. They will respond to external forces like drag, weight and rolling, along with forces applied to the saddle and handlebars (see Figure 1.5). During seated cycling, body weight is shared between the saddle, pedals and handlebars, with approximately 60% of cyclist's body mass directed to the back wheel [190]. Therefore, body weight adds to the gravity and inertial resistance along with the weight of bicycle components. During flat riding at speed greater than 20 km/h (~5.5 m/s), approximately 90% of the drag force is used to overcome air resistance [190]. Whenever level of terrain is changed, body-bicycle weight adds to the overall resistance (or ...

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... bikes (Figure 1.7) have been an option for almost all ages and population with recreational or competitive purposes. This bike is used for individual or group practice whenever held in paved roads to allow high traveling speeds (>50 km/h). Low handlebars enable a reduced projected area for better aerodynamic profile and low rolling resistance due to narrow tire type. In addition, the reduced mass for road bike (between 7-10 kg) results from the use of light materials for constructions (aluminum or carbon fiber) and to the absence of headlights or luggage space. The tires are narrow and flat, which also ensures low friction coefficient. The number of gears is between 10 and 20. Illustration of a road ...

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... between road and mountain bike cyclists were evident for ankle motion during similar exercise intensity and pedaling cadence (see Figure 10.4) [177]. Studies are needed to add to this comparison of motion analysis between cyclists of different disciplines. One potential reason for differences between disciplines is due to differences in bicycle configuration, which may in turn affect joint angles [146], but differences in the pedaling technique may also contribute to the specific kinematics between road and mountain cyclists. Further research is need to provide normative ranges of motion and joint angles, which can then be applied for adjusting bicycle components for cyclists of different disciplines. Adapted ...

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... settings are somewhat related to lower limb dimensions (i.e. throcantherion height shown in Figure 1.1-B). As an example, optimal saddle height should be 96-100% of the trochanterion height ...

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... Figure 1.1, bicycle and body dimensions are presented to highlight potential changes needed in bicycles to accommodate different lengths for segments of the cyclist. In Figure 1.1-A, we can see that bicycles enable users to change the distance from the saddle to the pedals and the horizontal distance from the saddle to the ...

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... Figure 1.1, bicycle and body dimensions are presented to highlight potential changes needed in bicycles to accommodate different lengths for segments of the cyclist. In Figure 1.1-A, we can see that bicycles enable users to change the distance from the saddle to the pedals and the horizontal distance from the saddle to the ...

Context 8

... components may have an effect in joint motion. Shan [182] observed larger range of motion for the ankle joint when non-cyclists pedaled using a device that reduced crank length at the power phase of crank cycle (from 12 to 3 o'clock). Smaller rotation was observed for the tibia when trained cyclists pedaled in the laboratory using the Rotor IV compared to circular chainrings [183] (Figure 11.4). ...

Context 9

... position of the foot on the pedal can be changed in several ways. When cyclists use a cleat between the shoe and the pedal the position of the foot-shoe in relation to the pedal can be changed in the anterior-posterior direction and rotated about the longitudinal axis (see Figures 1.8 and 2.8, respectively). The most common recommendation for optimal foot positioning is that the ball of the foot should lie over the pedal axis (see Figure 1) [6]. However, when the horizontal position of the foot on the pedal is varied (forward or backward, see Figure 1), no significant effects on knee joint forces [3], muscle activity [261], pedal forces [204] or oxygen uptake [262] are observed. Therefore, there is no current evidence to support that the horizontal position of the foot on the pedal can be optimized to reduce the risk of overuse injuries or improve ...

Context 10

... position of the foot on the pedal can be changed in several ways. When cyclists use a cleat between the shoe and the pedal the position of the foot-shoe in relation to the pedal can be changed in the anterior-posterior direction and rotated about the longitudinal axis (see Figures 1.8 and 2.8, respectively). The most common recommendation for optimal foot positioning is that the ball of the foot should lie over the pedal axis (see Figure 1) [6]. However, when the horizontal position of the foot on the pedal is varied (forward or backward, see Figure 1), no significant effects on knee joint forces [3], muscle activity [261], pedal forces [204] or oxygen uptake [262] are observed. Therefore, there is no current evidence to support that the horizontal position of the foot on the pedal can be optimized to reduce the risk of overuse injuries or improve ...

Context 11

... position of the foot on the pedal can be changed in several ways. When cyclists use a cleat between the shoe and the pedal the position of the foot-shoe in relation to the pedal can be changed in the anterior-posterior direction and rotated about the longitudinal axis (see Figures 1.8 and 2.8, respectively). The most common recommendation for optimal foot positioning is that the ball of the foot should lie over the pedal axis (see Figure 1) [6]. However, when the horizontal position of the foot on the pedal is varied (forward or backward, see Figure 1), no significant effects on knee joint forces [3], muscle activity [261], pedal forces [204] or oxygen uptake [262] are observed. Therefore, there is no current evidence to support that the horizontal position of the foot on the pedal can be optimized to reduce the risk of overuse injuries or improve ...

Context 12

... force is transferred to the pedals throughout bones and tendons but the direction of force application on the pedals depend on the position of the foot in relation to the pedal surface. For the analysis of force directions on the pedal surface, total (or resultant) pedal force is separated into three orthogonal components (normal -Fy, anterior-posterior -Fx and medio-lateral -Fz), as shown in Figure 1.2. Only normal and anterior-posterior pedal force components can be translated into crank torque depending on the position of the pedal in relation to the crank. This helps to explain why most studies focused only on the measurement of these two force components. Another reason could be associated to the increase in complexity from electronic settings when the medio-lateral force is measured along with rotation moments on the three-dimensional axes of the pedal. However, research has shown that increases in lateral force application on the pedal surface [78] and larger internal rotation moment along the Fy axle [79] could be associated to overload on the knee joint soft tissues ...

Context 13

... [10] presented a series of configurations of different components of the bicycle and their link to body dimensions. These have been largely used as an initial "guess" for selecting bicycle sizes and configuration of components. However, studies looking at the relationship between configurations of components taken from body dimensions and comfort showed a weak link [20,14]. For professional cyclists, reduced comfort has been found when cyclists were asked to use predictive "optimal" bicycle settings [20]. Similar results were observed in commuting cyclists with further findings on the weak relationship between self-selected saddle to handlebars length (as seen in Figure 1.1-A) and grip reach [14]. Therefore, it is unclear how valid predictive equations could be for definitions of "optimal" or "ideal" configuration of bicycle components ...

Context 14

... transducers, fiber optic and others) enabling tendon force records [97]. However, these methods require invasive procedures which are rarely observed in the literature [2,98]. With that in mind, biomechanists moved to a more indirect reflection of muscle force, which is muscle activation. The assessment of muscle activation as a reflection of muscle force has many limitations, but for some muscles in vary particular tasks, muscle force and surface electromyography (EMG) have shown to be related in animal models [99,100]. The physiological link is that, to increase force production, central nervous system generally relies on increasing muscle drive in order to enhance calcium availability for cross-bridges formation. In Figure 1.3, we briefly illustrate this sequence when motor neuron action potential is directed to muscle fibers, leading to recruitment of motor units and force production. In Figure 3.1 we can observe that Vastus Lateralis muscle is largely activated before peak pedal force is recorded, which suggests a delay in activation to force production. In the case of cycling, there are a series of reasons for the delay coming from physiological (e.g. time taken from action potential to elicit spread of calcium in ...

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... alternative approach to assess injury mechanism is the use of biomechanical methods to assess kinetics and kinematics of joint movements. The common approach assesses cyclists (or non-cyclists) with and without injuries in order to compute the predicted loads at a given joint (e.g. knee). For changes in saddle height, studies opted for this approach [30,3] given changes in saddle height potentially affect joint motion and knee loads. In Figure 1.6, a biomechanical model of the tibiofemoral and the patellofemoral joints is shown to illustrate the forces acting in these joints during pedaling. A limiting factor of this model is that it assumes joint follows a hinge type motion with no translation between bones. The assessment of individual-subjects moment-arms is also difficult and reference values from the literature are used to compute muscle-tendon forces from joint moments. In the case of multi-joint systems (e.g. spine), it is difficult to state a rotation axis and other approaches are preferred (e.g. finite elements analysis). For inverse dynamics models, muscle-tendon forces are calculated from net joint moments, which are commonly affected by effects from varying muscles. At the knee joint, force from quadriceps could be cancelled by hamstrings and gastrocnemius, which could reduce predicted muscle-tendon and joint forces. [229] were used to rate articles for the impact in 1a (systematic review of randomized controlled trials), 1b (randomized control trial study), 2a (systematic review from controlled case studies), 2b (controlled case studies), 3a (systematic review of case studies), ...