Acute effects of small changes in bicycle saddle height on gross efficiency and lower limb kinematics

The effect of saddle setback and cycling intensity on saddle pressures and comfort in male and female recreational cyclists

Cycling is a recreational activity that helps to prevent different diseases. The practice of this popular worldwide sport requires the cyclist to maintain a particular posture in contact with the pedals, handlebars, and saddle for long periods of time. Therefore, the study of the pressure exerted on the saddle is of great importance as it is directly related to the reduction of perineal injuries and pathologies. The present research aims to study the effect on comfort and saddle pressures when performing a cycloergometer test using 3 saddle positions: own setback position (P1), forward [-10% (P2)], backward [+10% (P3)] at two exercise intensities (Ventilatory Threshold: VT1 and VT2). 34 amateur cyclists (14 women, 20 men) were analysed. The results showed that comfort was significantly reduced in P3 (p < 0.01) and significantly increased for some items in the VT1 condition and for men in P1 regarding overall comfort (p < 0.01, ES = 0.105). In addition, the average and maximum pressure in the pubic region were significantly higher at P3 (p < 0.001) and men show higher values for average pressure compared to women (p = 0.006, ES = 0.235). In conclusion, backward saddle setback positions increase pressure and discomfort to recreational cyclists in comparison with the forward and own setback position, which could increase the risk of injury.

Acute effects of small changes in antero-posterior shoe-cleat position on physiological and biomechanical variables in road cycling

The aim of this study was to investigate the effect of changes in cycling shoe-cleat position on pedalling biomechanics, physiological variables, and performance in road cycling. Twelve competitive road cyclists performed three pedalling trials with the cleat positioned at the first metatarsal head, 15-mm anterior and 15-mm posterior. Each trial included three sets of 5 min performed at 35%, 50%, and 65% of maximal aerobic power (MAP) followed by a 10-s sprint. Results showed no significant changes in physiological variables, pedalling kinetics, muscular activity of six lower limb muscles, sprint performance and perceived exertion. However, significant differences were found regarding joint kinematics: hip, knee, and ankle angles during both extension and flexion were reduced in the anterior cleat position. Therefore, this study suggests that cleat position does not affect sprint performance, physiological variables, pedalling kinetics, muscle activity, and perceived exertion regardless of the cycling intensity. However, joint kinematics, and particularly knee extension angle which could be related to the risk of overuse injuries, was affected by the shoe-cleat position.

The effect of changes in saddle height on coordination and its variability during pedalling cycle

Modifications in saddle height affect the range of movement of the lower limb's joints during pedalling. Although its effect on movement patterns is poorly understood. The purpose of this study was to analyse the acute effects of small changes in bicycle saddle height on pedalling coordination and its variability. Lower extremity kinematic data were collected in random order for ten well-trained cyclists while pedalling at three different saddle heights: preferred, 2% higher and 2% lower than preferred position. A dynamical systems approach was used to quantify the coordination and its variability for selected joint couplings. Modifications in saddle height produced large changes in the frequency of movement patterns, although they were not enough to alter the coordination classification. Lowering the saddle height increased the frequency of the proximal coordinative hip-ankle pattern (F = 11.77, p < .01) and knee-ankle couplings (F = 14.39, p < .01), while decreasing inphase coordination (F > 11.03, p < .01) during the propulsive phase. Pedalling coordination variability was not affected, being greatest during the movement transitions and when the ankle joint was included in the coupling. This study demonstrated that pedalling pattern coordination and coordination variability were generally stable to acute small changes in saddle height in well-trained cyclists.

Methods to determine saddle height in cycling and implications of changes in saddle height in performance and injury risk: A systematic review

The objective of this systematic review was to assess the methods to determine bicycle saddle height and the effects of saddle height on cycling performance and injury risk outcomes. The key motivator of this review was to update and expand the finding reported by a previous narrative review published in 2011. The literature search included all documents from the following databases: Medline, Scopus, CINAHL, OVID and Google Scholar. Studies were screened against the Appraisal tool for Cross-sectional Studies to assess methodological quality and risk of bias. After screening the initial 29,398 articles identified, full-text screening was performed on 66 studies with 41 of these included in the systematic review. Strong evidence suggests that saddle height should be configured using dynamic measurements of the knee angle, and limb kinematics is influenced by changes in saddle height. However, moderate evidence suggests that changes in saddle height less than 4% of the leg length results in trivial to small changes in lower limb loads, and no effect on oxygen uptake and efficiency. It is also possible to state that there is limited evidence on the effects from changes in saddle height on supramaximal cycling performance or injury risk.

Freely chosen cadence during ergometer cycling is dependent on pedalling history

PURPOSE

History dependence can refer to the fact that parts of the human physiology (e.g., one or a group of muscles, or the nervous system) as well as functional aspects of the human (e.g., motor behaviour, or performance) depend on prior muscle activation. In the present study, it was investigated whether initial cycling at relatively low and high preset target cadences affected a subsequent freely chosen cadence at the end of the same bout of submaximal ergometer cycling.

METHODS

Twenty-two participants performed a single test session, which consisted of separate bouts of submaximal ergometer cycling. In one bout, cycling at 50 rpm was followed by cycling at freely chosen cadence. In another bout, cycling at 90 rpm was followed by cycling at freely chosen cadence. In yet another bout (denoted reference), the cadence was freely chosen throughout. Behavioural (cadence), biomechanical (tangential pedal force), and physiological (heart rate) responses were measured.

RESULTS

Increased cadence resulted in decreased maximal tangential pedal force in accordance with existing knowledge. Initial cycling at 50 and 90 rpm caused freely chosen cadence to be about 5% lower and higher, respectively, than the freely chosen cadence (72.4 ± 2.4 rpm) at the end of the reference bout. These differences in cadence were not accompanied by statistically significant differences in heart rate.

CONCLUSION

The freely chosen cadence depended on the preset cadence applied at the beginning of the bout. This was denoted a phenomenon of motor behavioural history dependence.

Prevalence and functional implications of Soleus and Tibialis anterior activation strategies during cycling

Key areas of sports science research investigate the functional role of muscle activations within human movement. Even within relatively constrained movements like cycling, significant variability is observed in muscle activation strategies. Particular attention has been given to particular muscles, despite Soleus and Tibialis anterior muscles presenting a potentially functionally relevant split between monomodal and bimodal activation strategies. The current study (N = 54) investigated the prevalence and functional implications of these different strategies and identified, in addition to monomodal [Soleus: N = 24, Tibialis anterior: N = 7] and bimodal [Soleus: N = 12, Tibialis anterior: N = 31] strategies, a third group switching between strategies [Soleus: N = 16, Tibialis anterior: N = 13]. The combined Soleus group showed significantly higher Index of Force Effectiveness, lower negative work and lower radial forces than the bimodal group. Furthermore, bimodal Soleus strategies produced a period of significantly greater plantar flexion during the upstroke. No differences were found between the Tibialis anterior groups. These data show an identifiable group of cyclists utilising a combination of monomodal and bimodal strategies potentially benefiting mechanical effectiveness. Awareness of such functional implications can aid researchers and practitioners when interpreting cycling biomechanics data or intervention responses. Further research should investigate the factors that mediate transitions between activation strategies within the combined groups.

Changes in the Trunk and Lower Extremity Kinematics Due to Fatigue Can Predispose to Chronic Injuries in Cycling

Kinematic analysis of the cycling position is a determining factor in injury prevention and optimal performance. Fatigue caused by high volume training can alter the kinematics of the lower body and spinal structures, thus increasing the risk of chronic injury. However, very few studies have established relationships between fatigue and postural change, being these in 2D analysis or incremental intensity protocols. Therefore, this study aimed to perform a 3D kinematic analysis of pedaling technique in a stable power fatigue protocol 23 amateur cyclists (28.3 ± 8.4 years) participated in this study. For this purpose, 3D kinematics in hip, knee, ankle, and lumbar joints, and thorax and pelvis were collected at three separate times during the protocol. Kinematic differences at the beginning, middle, and end of the protocol were analyzed for all joints using one-dimensional statistical parametric mapping. Significant differences (p < 0.05) were found in all the joints studied, but not all of them occur in the same planes or the same phase of the cycle. Some of the changes produced, such as greater lumbar and thoracic flexion, greater thoracic and pelvic tilt, or greater hip adduction, could lead to chronic knee and lumbar injuries. Therefore, bike fitting protocols should be carried out in fatigue situations to detect risk factor situations.

Influence of Sex on Current Methods of Adjusting Saddle Height in Indoor Cycling

ABSTRACT

Encarnación-Martínez, A, Ferrer-Roca, V, and García-López, J. Influence of sex on current methods of adjusting saddle height in indoor cycling. J Strength Cond Res 35(2): 519-526, 2021-The popularity of indoor cycling has increased in fitness centers, and therefore, proper bike fitting is important to avoid biomechanical-related injuries. However, no previous studies have compared the biomechanical kinematics of various existing protocols of saddle-height adjustment in indoor cycling. Furthermore, it was not clear if these protocols were appropriate for both men and women, as these equations were primarily obtained in male cyclists. Therefore, lower-limb joint kinematics were compared among 4 different protocols of saddle-height adjustment (1-Preferred, 2-Ferrer-Roca et al., 3-Lemond & Guimard, and 4-Static Goniometry) in 30 experienced indoor-cycling subjects (15 men and 15 women). Only 20-33% of the women had a knee extension while pedaling within the recommended range for each of the different protocols except for the preferred adjustment (73% were within). By contrast, all the protocols were moderately suitable for men (47-60% were within the recommended range). A multiple linear equation to estimate the recommended saddle height in both men and women (R2 = 0.917, p = 0.001) was obtained from the following variables: inseam length, stature, foot length, and knee angle. The differences in the findings between men and women may be partially explained by differences in anatomical structures, as well as the male-based equations, which argues the need for future investigations in female cyclists.

Influence of saddle height in 3D knee loads commuter cyclists: A statistical parametric mapping analysis

This study used a statistical parametric mapping method to compare temporal patterns knee joint loads and moments in cyclists pedalling using different saddle heights. Ten recreational cyclists pedalled using three saddle heights (Preferred, High and Low) during a single session. High and Low saddle heights were determined based on dynamically measured knee flexion angles (±10° from their Preferred height). 3D angles for the hip and knee and knee moments and forces were computed using a musculoskeletal model driven by 3D full-body motion and pedal forces. Knee flexion angles presented significant differences between saddle heights for the full crank cycle, without differences for hip adduction/abduction. Patellofemoral force was less for the Preferred compared to the High and Low saddle heights and for the High compared to the Low saddle heights between ~70-160° of the crank cycle. Right tibiofemoral anterior-posterior shear force was reduced for the Preferred compared to the Low saddle heights, without significant effects for the left tibiofemoral joint (p = 0.29-1.00). Large differences in temporal patterns for knee flexion due to changes in saddle height were followed by differences in patellofemoral force mostly when low force magnitudes were being transmitted between the femur and the patella.

Muscle force adaptation to changes in upper body position during seated sprint cycling

Sprint cycling performance depends upon the balance between muscle and drag forces. This study assessed the influence of upper body position on muscle forces and aerodynamics during seated sprint cycling. Thirteen competitive cyclists attended two sessions. The first session was used to determine handlebar positions to achieve pre-determined hip flexion angles (70-110° in 10° increments) using dynamic bicycle fitting. In the second session, full body kinematics and pedal forces were recorded throughout 2x6-s seated sprints at the pre-determined handlebar positions, and frontal plane images were used to determine the projected frontal area. Leg work, joint work, muscle forces and frontal area were compared at three upper body positions, being optimum (maximum leg work), optimal+10° and optimal-10° of hip flexion. Larger hip (p = 0.01-0.02) and reduced knee (p = 0.02-0.03) contribution to leg work were observed at the optimal+10° position without changes at the ankle joint (p = 0.39). No differences were observed in peak muscle forces across the three body positions (p = 0.06-0.48). Frontal area was reduced at optimum+10° of hip flexion when compared to optimum (p = 0.02) and optimum-10° (p < 0.01). These findings suggest that large changes in upper body position can influence aerodynamics and alter contributions from the knee and hip joints, without influencing peak muscle forces.

Comparison of two static methods of saddle height adjustment for cyclists of different morphologies

Methods based on inseam length (IL) for saddle height adjustment in cycling are frequently employed. However, these methods were designed for medium-sized people. The aim of this study was to evaluate knee angle during pedalling by 2D video analysis and perceived comfort using a subjective scale under three saddle height conditions: (1) self-selected saddle height, (2) Genzling method (0.885 × IL) and (3) Hamley method (1.09 × IL minus crank arm length). Twenty-six cyclists of heterogeneous morphology were recruited. Three groups were determined based on IL: Short (IL < 0.8 m), Medium (0.8 m < IL< 0.88 m) and Long (IL > 0.88 m). The results showed that Medium and Long IL groups usually rode with saddle heights allowing knee angles consistent with those previously shown to prevent injuries (30°-40°). However, Short IL group, who were all children, self-selected a too low saddle height (knee angle was too large). Genzling and Hamley methods gave identical results for Medium IL group, permitting knee angles in the range of 30°-40°. However, both methods caused important differences between Short and Long IL groups. Hamley method was more suitable for short ILs, while Genzling method was more suitable for long ILs.

Saddle Height and Cadence Effects on the Physiological, Perceptual, and Affective Responses of Recreational Cyclists

Saddle height influences cycling performance and would be expected to influence cyclists physically, perceptually, and emotionally. We investigated how different saddle positions and cadences might affect cyclists’ torque, heart rate, rate of perceived exertion (RPE), and affective responses (Feeling scale). Nine male recreational cyclists underwent cycling sessions on different days under different conditions with a constant load. On Day 1, the saddle was at the reference position (109% of the distance from the pubic symphysis to the ground), and on Days 2 and 3, the saddle was in the “upward position” (reference + 2.5%) and “downward position” (reference − 2.5%) in random order. Each session lasted 30 minutes and was divided into three cadence-varied 10-minute stages without interruption: (a) freely chosen cadence (FCC), (b) FCC − 20%, and (c) FCC + 20%. We assessed all dependent measures at the end of each 10 minute stage. While there was no significant interaction (Saddle × Cadence) for any of the analyzed variables, torque values were higher at lower cadences in all saddle configurations, and the FCC + 20% cadence was associated with faster heart rate, higher RPE, and lower affect compared with FCC and FCC − 20% in all saddle positions. At all cadences, the saddle at “downward position” generated a higher RPE compared with “reference position” and “upward position.” The affective response was lower in the “downward position” compared with the “reference position.” Thus, while cyclists perceived the downward (versus reference) saddle position as greater exercise effort, they also associated it with unpleasant affect.

Acute effects of small changes in crank length on gross efficiency and pedalling technique during submaximal cycling

The main purpose of this study was to assess the acute effects of small changes in crank length (assumable by competitive cyclists) on metabolic cost and pedalling technique during submaximal cycling. Twelve amateur road cyclists performed three sets of submaximal pedalling (150, 200 and 250 W) at a constant cadence (91.3 ± 0.8 rpm) in a randomised order with three commonly used crank lengths, preferred (172.5-175 mm), +5 mm and -5 mm. Energy cost of pedalling, kinetic and kinematic variables were simultaneously registered. Changes in crank length had no significant effect on heart rate (144 ± 13, 145 ± 12 and 145 ± 13 bpm, respectively) and gross efficiency (GE) (20.4 ± 2.1, 20.1 ± 2.2 and 20.3 ± 2.4%, respectively). A longer crank induced a significant (P < 0.05) reduction of positive impulse proportion (PIP) (0.9-1.9%) due to a greater maximum (1.0-2.3 N · m) and minimum torque (1.0-2.2 N · m). At the same time, the maximum flexion and range of motion of the hip and knee joints were significantly increased (1.8-3.4° and P < 0.05), whereas the ankle joint was not affected. In conclusion, the biomechanical changes due to a longer crank did not alter the metabolic cost of pedalling, although they could have long-term adverse effects. Therefore, in case of doubt between two lengths, the shorter one might be recommended.

Relative variances of the cadence frequency of cycling under two differential saddle heights

[Purpose] Bicycle saddle height is a critical factor for cycling performance and injury prevention. The present study compared the variance in cadence frequency after exercise fatigue between saddle heights with 25° and 35° knee flexion. [Methods] Two saddle heights, which were determined by setting the pedal at the bottom dead point with 35° and 25° knee flexion, were used for testing. The relative variances of the cadence frequency were calculated at the end of a 5-minute warm-up period and 5 minutes after inducing exercise fatigue. Comparison of the absolute values of the cadence frequency under the two saddle heights revealed a difference in pedaling efficiency. [Results] Five minutes after inducing exercise fatigue, the relative variances of the cadence frequency for the saddle height with 35° knee flexion was higher than that for the saddle height with 25° knee flexion. [Conclusion] The current finding demonstrated that a saddle height with 25° knee flexion is more appropriate for cyclists than a saddle height with 35° knee flexion.