Bicycle Set-Up Dimensions and Cycling Kinematics: A Consensus Statement Using Delphi Methodology

Bicycle set-up dimensions and cycling kinematic data are important components of bicycle fitting and cyclist testing protocols. However, there are no guidelines on how bicycles should be measured and how kinematic data should be collected to increase the reliability of outcomes. This article proposes a consensus regarding bicycle set-up dimensions and recommendations for collecting cycling-related kinematic data. Four core members recruited panellists, prepared the document to review in each round for panellists, analysed the scores and comments of the expert panellists, reported the decisions and communicated with panellists. Fourteen experts with experience in research involving cycling kinematics and/or bicycle fitting agreed to participate as panellists. An initial list of 17 statements was proposed, rated using a five-point Likert scale and commented on by panellists in three rounds of anonymous surveys following a Delphi procedure. The consensus was agreed upon when more than 80% of the panellists scored the statement with values of 4 and 5 (moderately and strongly agree) with an interquartile range of less than or equal to 1. A consensus was achieved for eight statements addressing bicycle set-up dimensions (e.g. saddle height, saddle setback, etc.) and nine statements for cycling kinematic assessment (e.g. kinematic method, two-dimensional methodology, etc.). This consensus statement provides a list of recommendations about how bicycle set-up dimensions should be measured and the best practices for collecting cycling kinematic data. These recommendations should improve the transparency, reproducibility, standardisation and interpretation of bicycle measurements and cycling kinematic data for researchers, bicycle fitters and cycling related practitioners.

Cycling position optimisation - a systematic review of the impact of positional changes on biomechanical and physiological factors in cycling

Bike positional configuration changes strongly affect cycling performance. While consensus has emerged on saddle height optimisation, there is none for the relationship between other bike positional variables and cycling performance. Accordingly, this systematic review examines the effect of all major positional variables on performance in cycling, assessing differences between cycling disciplines and sex where possible. The systematic review, conducted per PRISMA guidelines, searched databases including Embase, Web of Science, Medline, and CINAHL, screening 16,578 studies. Of these, 47 were fully analysed. Study quality assessment using the NIH tool revealed none rated "good", 5 "fair" and 33 "poor". The analysis involved 724 participants (90 female, 454 male, 180 sex unstated). Studies focused on trunk angle/upper body position, handlebar height, Q factor, foot position, saddle fore-aft/height, seat tube angle and crank length. Participant cycling disciplines were often unspecified and few papers address women cyclists specifically. Key findings were associated with changing saddle height, trunk angle and saddle fore-aft. For trunk angle, accounting for the biomechanical and physiological effects as well as aerodynamic changes is important. Saddle fore-aft affects the hip angle and trunk angle. There are no clear recommendations for crank length, handlebar height, Q factor or cleat position.

Validity, reliability, and bias between instrumented pedals and loadsol insoles during stationary cycling

The purpose of this study was to evaluate the validity and reliability of the loadsol in measuring pedal reaction force (PRF) during stationary cycling as well as lower limb symmetry. Ten healthy participants performed bouts of cycling at 1kg, 2kg, and 3kg workloads (conditions) on a cycle ergometer. The ergometer was fitted with instrumented pedals and participants wore loadsol plantar pressure insoles. A 3 x 2 (Condition x Sensor Type) ANOVA was used to examine the differences in measured peak PRF, impulse, and symmetry indices. Root mean square error, intraclass correlation coefficients, and Passing-Bablok regressions were used to further assess reliability and validity. The loadsol demonstrated poor (< 0.5) to excellent (> 0.9) agreement as measured by intraclass correlation coefficients for impulse and peak PRF. Passing-Bablok regression revealed a systematic bias only when assessing all workloads together for impulse with no bias present when looking at individual workloads. The loadsol provides a consistent ability to measure PRF and symmetry when compared to a gold standard of instrumented pedals but exhibits an absolute underestimation of peak PRF. This study provides support that the loadsol can identify and track symmetry differences in stationary cycling which means there is possible usage for clinical scenarios and interventions in populations with bilateral asymmetries such as individuals with knee replacements, limb length discrepancies, diabetes, or neurological conditions. Further investigation of bias should be conducted in longer cycling sessions to ensure that the loadsol system is able to maintain accuracy during extended use.

Alternative Models for Pelvic Marker Occlusion in Cycling

Bike fitting aims to optimize riders' positions to improve their performance and reduce the risk of injury. To calculate joint angles, the location of the joint centers of the lower limbs needs to be identified. However, one of the greatest difficulties is the location of the hip joint center due to the frequent occlusion of the anterior superior iliac spine markers. Therefore, the objective of this study was to validate a biomechanical model adapted to cycling (modified pelvic model, MPM), based on the traditional pelvic model (TPM) with an additional lateral technical marker placed on the iliac crests. MPM was also compared with a widely used model in cycling, trochanter model (TM). Thirty-one recreational cyclists pedaled on a roller bike while the movement was captured with a 7-camera VICON system. The position of the hip joint center and knee angle were calculated and compared with the TPM continuously (along 10 pedaling cycles) and discreetly at 90° and 180° crank positions. No significant differences were found in the position of the hip joint center or in the knee flexion/extension angle between the TPM and the MPM. However, there are differences between TPM and TM (variations between 4.1° and 6.9° in favor of the TM at 90° and 180°; P < .001). Bland-Altman graphs comparing the models show an average difference or bias close to 0° (limits of agreement [0.2 to -8.5]) between TPM and MPM in both lower limbs and a mean difference of between -4° and -7° (limits of agreement [-0.6 to -13.2]) when comparing TPM and TM. Given the results, the new cycling pelvic model has proven to be valid compared with the TPM when performing bike fitting studies, with the advantage that the occluded markers are avoided. Despite its simplicity, the TM presents measurement errors that may be relevant when making diagnoses, which makes its usefulness questionable.

The Effects of Post-Exercise Cold Water Immersion on Neuromuscular Control of Knee

To date, most studies examined the effects of cold water immersion (CWI) on neuromuscular control following exercise solely on measuring proprioception, no study explores changes in the brain and muscles. The aim of this study was to investigate the effects of CWI following exercise on knee neuromuscular control capacity, and physiological and perceptual responses. In a crossover control design, fifteen participants performed an exhaustion exercise. Subsequently, they underwent a 10 min recovery intervention, either in the form of passively seated rest (CON) or CWI at 15 °C. The knee proprioception, oxygenated cerebral hemoglobin concentrations (Δ[HbO]), and muscle activation during the proprioception test, physiological and perceptual responses were measured. CWI did not have a significant effect on proprioception at the post-intervention but attenuated the reductions in Δ[HbO] in the primary sensory cortex and posterior parietal cortex (p < 0.05). The root mean square of vastus medialis was higher in the CWI compared to the CON. CWI effectively reduced core temperature and mean skin temperature and improved the rating of perceived exertion and thermal sensation. These results indicated that 10 min of CWI at 15 °C post-exercise had no negative effect on the neuromuscular control of the knee joint but could improve subjective perception and decrease body temperature.

Effects of workload and saddle height on muscle activation of the lower limb during cycling

BACKGROUND

Cycling workload is an essential factor in practical cycling training. Saddle height is the most studied topic in bike fitting, but the results are controversial. This study aims to investigate the effects of workload and saddle height on the activation level and coordination of the lower limb muscles during cycling.

METHODS

Eighteen healthy male participants with recreational cycling experience performed 15 × 2-min constant cadence cycling at five saddle heights of 95%, 97%, 100%, 103%, and 105% of greater trochanter height (GTH) and three cycling workloads of 25%, 50%, and 75% of functional threshold power (FTP). The EMG signals of the rectus femoris (RF), tibialis anterior (TA), biceps femoris (BF), and medial gastrocnemius (MG) of the right lower limb were collected throughout the experiment.

RESULTS

Greater muscle activation was observed for the RF and BF at a higher cycling workload, whereas no differences were observed for the TA and MG. The MG showed intensified muscle activation as the saddle height increased. The mean and maximum amplitudes of the EMG signals of the MG increased by 56.24% and 57.24% at the 25% FTP workload, 102.71% and 126.95% at the 50% FTP workload, and 84.27% and 53.81% at the 75% FTP workload, respectively, when the saddle height increased from 95 to 100% of the GTH. The muscle activation level of the RF was minimal at 100% GTH saddle height. The onset and offset timing revealed few significant differences across cycling conditions.

CONCLUSIONS

Muscle activation of the RF and BF was affected by cycling workload, while that of the MG was affected by saddle height. The 100% GTH is probably the appropriate saddle height for most cyclists. There was little statistical difference in muscle activation duration, which might be related to the small workload.

Bilateral trochlear subchondral insufficieny fracture of the knee in a professional cyclist

This case report presents a rare case of subsequent ipsilateral and contralateral subchondral insufficiency fracture of the knee (SIFK) in the trochlea of the femur within months, manifested in a professional cyclist. SIFKs in the trochlea have not yet been reported in the literature; however, their appearance in a professional cyclist might be explained by the amount of repetitive pressure on the patellofemoral joint when cycling. In both instances, atraumatic anterior knee pain occurred, resolving after conservative treatment for 6-9 weeks. The patient reached their previous activity level. The authors believe SIFK in the younger population may be more common than currently perceived due to its self-limiting behaviour and a lack of performing immediate MRIs in this younger group whenever an overload injury is suspected.

Saddle Pressures Factors in Road and Off-Road Cyclists of Both Genders: A Narrative Review

The contact point of the pelvis with the saddle of the bicycle could generate abnormal pressure, which could lead to injuries to the perineum in cyclists. The aim of this review was to summarize in a narrative way the current literature on the saddle pressures and to present the factors that influence saddle pressures in order to prevent injury risk in road and off-road cyclists of both genders. We searched the PubMed database to identify English-language sources, using the following terms: "saddle pressures", "pressure mapping", "saddle design" AND "cycling". We also searched the bibliographies of the retrieved articles. Saddle pressures are influenced by factors such as sitting time on the bike, pedaling intensity, pedaling frequency, trunk and hand position, handlebars position, saddle design, saddle height, padded shorts, and gender. The jolts of the perineum on the saddle, especially on mountain bikes, generate intermittent pressures, which represent a risk factor for various pathologies of the urogenital system. This review highlights the importance of considering these factors that influence saddle pressures in order to prevent urogenital system injuries in cyclists.

Pain and body position on the bicycle in competitive and recreational road cyclists: A retrospective study

This study compared the presence of pain in recreational and competitive road cyclists and body position on the bicycle between cyclists with and without pain. Seventy-one cyclists completed a survey reporting existing cycling-related sites of pain and comfort. Static sagittal and frontal plane images were taken to analyse body position on the bicycle. Participants were separated into recreational and competitive road cycling groups, and further into cyclists reporting pain in the upper body, low back, buttocks/hips and knees for comparison with cyclists without pain. A logistic regression model investigated possible predictors of pain whilst cycling. Pain was present in 67% of recreational and 70% of competitive cyclists whilst comfort was reported by 81% of recreational and 75% of competitive cyclists. Trivial to moderate non-significant differences were observed for body position on the bicycle between cyclists with and without pain, and between cyclists with and without pain in the upper body, low back, buttocks/hips and knees. The predictive logistic model was not significant (p = 0.07) with a model fit predicted by McFadden R² of 0.07. Given most cyclists reported both pain and comfort, comfort is probably not a good predictor of overuse injury risk.

Effects of Knee Extension Joint Angle on Quadriceps Femoris Muscle Activation and Exerted Torque in Maximal Voluntary Isometric Contraction

This study investigated the effects of knee joint angle on muscle activation, exerted torque, and whether the knee angle affects the muscle activation−torque ratio. Nine healthy adult male participants participated in the study. They performed maximal voluntary isometric contraction (MVIC) at six (80°, 90°, 100°, 110°, 120°, and 130°) different knee joint angles (i.e., angles between the thigh and shin bones). Their maximal torque was assessed utilizing an isokinetic chair, while their muscle activation (root mean square [RMS]) was assessed using an eight-channel single differential surface EMG sensor. For the purposes of the torque−knee angle relationship and muscle activation−knee angle relationship, the torque and RMS were normalized relative to the maximal value obtained by each participant. To evaluate the muscle activation−torque ratio in function of knee angle, RMS was normalized relative to the corresponding torque obtained at each knee angle. Repeated measure analysis of variance was used to investigate the effects of knee angle on muscle activation, torque, and muscle activation−torque ratio. There was a significant effect of knee joint angle on normalized torque (F = 27.521, p < 0.001), while the activation of vastus lateralis and vastus medialis remained unchanged. The changes in knee angle affected the muscle activation−torque ratio of vastus lateralis (Chi-square = 16.246, p = 0.006) but not the vastus medialis. These results suggest that knee joint angles from 80° to 130° provide a stable milieu for muscle electrification, while mechanical factor such as knee joint angle (i.e., lever arm length) affect the torque output when one needs to contract quadriceps maximally during the isometric contraction.

Long-Term Effects of a Kinematic Bikefitting Method on Pain, Comfort, and Fatigue: A Prospective Cohort Study

The purpose of this study is to analyze the long-term riders' subjective responses to a standardized bikefitting method on their bicycles. Eighty-six amateur mountain bikers had their riding posture and bicycle components ergonomically adjusted through a 3D kinematic bikefitting method. Validated subjective scales (Feeling, OMNI, and Numerical Rating Pain Scale) were used to assess their overall riding comfort and fatigue along with localized pain for six body parts. Data were collected just before intervention (baseline or pre), immediately after (or post), and 30, 60, 90, and 120 days after the bikefit session. A Student's t-test comparing before bikefit and after 120 days showed significant (p < 0.05) reduction in localized pain for all six body parts and riding comfort along with a large effect size effect (d = 1.18) for riding comfort. Although initially reduced, fatigue scores gradually increased over the months, showing a high correlation (r = 0.946) with increased monthly training volume. In conclusion, overall riding discomfort and pain were significantly decreased after a standardized kinematic bikefit session even after 120 days post intervention. However, fatigue scores began to rise after 30 days, showing a high correlation with increasing monthly training volume.

Effects of Different Pedaling Positions on Muscle Usage and Energy Expenditure in Amateur Cyclists

BACKGROUND

Inappropriate cycling positions may affect muscle usage strategy and raise the level of fatigue or risk of sport injury. Dynamic bike fitting is a growing trend meant to help cyclists select proper bikes and adjust them to fit their ergometry. The purpose of this study is to investigate how the "knee forward of foot" (KFOF) distance, an important dynamic bike fitting variable, influences the muscle activation, muscle usage strategy, and rate of energy expenditure during cycling.

METHODS

Six amateur cyclists were recruited to perform the short-distance ride test (SRT) and the graded exercise tests (GXT) with pedaling positions at four different KFOF distances (+20, 0, -20, and -40 mm). The surface electromyographic (EMG) and portable energy metabolism systems were used to monitor the muscle activation and energy expenditure. The outcome measures included the EMG root-mean-square (RMS) amplitudes of eight muscles in the lower extremity during the SRT, the regression line of the changes in the EMG RMS amplitude and median frequency (MF), and the heart rate and oxygen consumption during the GXT.

RESULTS

Our results revealed significant differences in the muscle activation of vastus lateralis, vastus medialis, and semitendinosus among four different pedaling positions during the SRT. During GXT, no statistically significant differences in muscle usage strategy and energy expenditure were found among different KFOF. However, most cyclists had the highest rate of energy expenditure with either KFOF at -40 mm or 20 mm.

CONCLUSIONS

The KFOF distance altered muscle activation in the SRT; however, no significant influence on the muscle usage strategy was found in the GXT. A higher rate of energy expenditure in the extreme pedaling positions of KFOF was observed in most amateur cyclists, so professional assistance for proper bike fitting was recommended.

Validity and Reliability of the Leomo Motion-Tracking Device Based on Inertial Measurement Unit with an Optoelectronic Camera System for Cycling Pedaling Evaluation

Background: The use of inertial measurement sensors (IMUs), in the search for a more ecological measure, is spreading among sports professionals with the aim of improving the sports performance of cyclists. The kinematic evaluation using the Leomo system (TYPE-R, Leomo, Boulder, CO, USA) has become popular. Purpose: The present study aimed to evaluate the reliability and validity of the Leomo system by measuring the angular kinematics of the lower extremities in the sagittal plane during pedaling at different intensities compared to a gold-standard motion capture camera system (OptiTrack, Natural Point, Inc., Corvallis, OR, USA). Methods: Twenty-four elite cyclists recruited from national and international cycling teams performed two 6-min cycles of cycling on a cycle ergometer at two different intensities (first ventilatory threshold (VT1) and second ventilatory threshold (VT2)) in random order, with a 5 min rest between intensity conditions. The reliability and validity of the Leomo system versus the motion capture system were evaluated. Results: Both systems showed high validity and were consistently excellent in foot angular range Q1 (FAR (Q1)) and foot angular range (FAR) (ICC-VT1 between 0.91 and 0.95 and ICC-VT2 between 0.88 and 0.97), while the variables leg angular range (LAR) and pelvic angle showed a modest validity (ICC-VT1 from 0.52 to 0.71 and ICC-VT2 between 0.61 and 0.67). Compared with Optitrack, Leomo overestimated all the variables, especially the LAR and pelvic angle values, in a range between 12 and 15°. Conclusions: Leomo is a reliable and valid tool for analyzing the ranges of motion of the cyclist’s lower limbs in the sagittal plane, especially for the variables FAR (Q1) and FAR. However, its systematic error for FAR and Pelvic Angle values must be considered in sports performance analysis.

Effects of the real-time feedback and knee taping on lower-extremity function during ergometer pedaling in subjects with tibiofemoral varus alignment

BACKGROUND

The effect of the Posterior X Taping (PXT) used for subjects with Tibiofemoral Varus Malalignment (TFRV) aimed to control excessive tibiofemoral rotations is still unclear. Further, it is critical to use evidence-based therapeutic exercises to prevent non-contact injuries, especially in repetitive movements.

OBJECTIVE

To investigate whether the PXT and real-time feedback (RTF) interventions would improve lower extremity functions during the pedaling task in subjects with TFRV.

METHODS

Twenty-four male recreational athletes with TFRV participated in this study; Kinematic and muscle activity were synchronously recorded on ten consecutive pedal cycles during the last 30 s of 2-min pedaling.

RESULTS

The present study indicated that the subjects at the post-intervention of the RTF group exhibited significant decreased hip adduction and internal rotation, significant decreased tibiofemoral external rotation between 144° and 216° of crank angle, significant increased vastus medialis activity between 144° and 288° of crank angle, and significant increased gluteus medius activity between 180° and 144° of crank angle; In contrast, the subjects at the post-intervention of the PXT group exhibited significant decreased tibiofemoral external rotation and increased ankle external rotation at all the crank angles. No between-group differences were observed in pre-and post-intervention.

SIGNIFICANCE

These results suggest that the PXT and RTF interventions are recommended to immediately improve the functional defects of the subjects with TFRV during the pedaling task.

Smart Electrically Assisted Bicycles as Health Monitoring Systems: A Review

This paper aims to provide a review of the electrically assisted bicycles (also known as e-bikes) used for recovery of the rider's physical and physiological information, monitoring of their health state, and adjusting the "medical" assistance accordingly. E-bikes have proven to be an excellent way to do physical activity while commuting, thus improving the user's health and reducing air pollutant emissions. Such devices can also be seen as the first step to help unhealthy sedentary people to start exercising with reduced strain. Based on this analysis, the need to have e-bikes with artificial intelligence (AI) systems that recover and processe a large amount of data is discussed in depth. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used to complete the relevant papers' search and selection in this systematic review.

Cycling kinematics in healthy adults for musculoskeletal rehabilitation guidance

Background

Stationary cycling is commonly used for postoperative rehabilitation of physical disabilities; however, few studies have focused on the three-dimensional (3D) kinematics of rehabilitation. This study aimed to elucidate the three-dimensional lower limb kinematics of people with healthy musculoskeletal function and the effect of sex and age on kinematics using a controlled bicycle configuration.

Methods

Thirty-one healthy adults participated in the study. The position of the stationary cycle was standardized using the LeMond method by setting the saddle height to 85.5% of the participant’s inseam. The participants maintained a pedaling rate of 10–12 km/h, and the average value of three successive cycles of the right leg was used for analysis. The pelvis, hip, knee, and ankle joint motions during cycling were evaluated in the sagittal, coronal, and transverse planes. Kinematic data were normalized to 0–100% of the cycling cycle. The Kolmogorov-Smirnov test, Mann-Whitney U test, Kruskal-Wallis test, and k-fold cross-validation were used to analyze the data.

Results

In the sagittal plane, the cycling ranges of motion (ROMs) were 1.6° (pelvis), 43.9° (hip), 75.2° (knee), and 26.9° (ankle). The coronal plane movement was observed in all joints, and the specific ROMs were 6.6° (knee) and 5.8° (ankle). There was significant internal and external rotation of the hip (ROM: 11.6°), knee (ROM: 6.6°), and ankle (ROM: 10.3°) during cycling. There was no difference in kinematic data of the pelvis, hip, knee, and ankle between the sexes (p = 0.12 to 0.95) and between different age groups (p = 0.11 to 0.96) in all anatomical planes.

Conclusions

The kinematic results support the view that cycling is highly beneficial for comprehensive musculoskeletal rehabilitation. These results might help clinicians set a target of recovery ROM based on healthy and non-elite individuals and issue suitable guidelines to patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04905-2.

Lumbar Spine and Lower Extremity Overuse Injuries

Both lower extremities and lower back are common sources of injury for cyclists. For providers to optimize care within this area of sports medicine, they need to understand the most common sources of injury in this population. Cycling presents a unique challenge: treating both the athlete and the complex relationship between rider and bicycle. Physicians should not replace the role of a professional bike fitter and should view these individuals as integral members of the team to alleviate current and prevent future injury. This article explores common lower extremity and lumbar back overuse injuries in cyclists and their medical management.

Adaptive Cycling: Classification, Adaptations, and Biomechanics

Increased awareness, recognition, and accessibility has led to an increase in the popularity of adaptive cycling. This article aims to provide up-to-date information for clinicians about available adaptations, participation options, and resources. We review the para-cycling classification system and 4 main categories of cycles. There are multiple considerations for fit and customization depending on an individual's disability to improve efficiency and comfort. Virtual platforms that allow riders to train and compete online have grown in popularity among para-cycling communities and offer an alternative to riding outdoors. Many national and local organizations offer communities and grants to assist with adaptive equipment.

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.

Modeling cycling performance: Effects of saddle position and cadence on cycle pedaling efficiency

The modeling method is an effective means of estimating causality as well as examining cycle pedaling efficiency. Pedaling efficiency can also be examined by an experimental method, but the experimental method can lead to contradictory results due to perturbation of the measured output parameters. Experimental studies generally yield realistic results, but it is difficult to control for all the variables of interest and to determine the causal relationships between them. The objective of this study is to investigate the pedaling efficiency and causality with considering saddle position and pedaling cadence as variables. Based on the mathematical pedaling modeling, the internal work calculation method was used to calculate the consumed mechanical energy and energy conservation percentage (C s ). The optimal saddle position with the lowest mechanical energy and the highest energy conservation percentage could be changed by the cadence. At the low cadence, the higher saddle position, and the shorter horizontal distance between the saddle and crankshaft led to higher pedaling efficiency (h: 0.95 m, d: 0.16 m, and knee angle: 28 ° ). However, the highest pedaling efficiency was achieved at the high cadence with a saddle height (h) of 0.9 m and a horizontal distance between the saddle and the crankshaft (d) of 0.06 m (knee angle: 48 ° ). The lowest cadence is the optimal cadence in terms of the consumed energy, but the optimal cadence was 90 r/min in terms of the energy conservation percentage. Compared to the energy consumption, the energy conservation percentage was demonstrated to influence the fatigue of a cycle rider more critically. The energy conservation percentage was highest at 90 r/min, and 90 r/min was close to the preferred cadence by the cyclist.

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.

Equations to Prescribe Bicycle Saddle Height based on Desired Joint Kinematics and Bicycle Geometry

METHODS

Forty healthy adults (17 women, 23 men; mean (SD): 28.6 (7.2) years; 24.2 (2.6) kg/m²) participated. Kinematic analyses were conducted for 18 three-minute bicycling bouts including all combinations of 3 horizontal and 3 vertical saddle positions, and 2 crank arm lengths. For both minimum and maximum knee flexion, predictors were identified using Least Absolute Shrinkage and Selection Operator (LASSO) regression, and final models were fit using linear regression. Secondary analyses determined if saddle height equations were sex dependent.

RESULTS

The equation to predict saddle position from minimum knee flexion angle (R²=0.97; root mean squared error (RMSE) = 1.15 cm) was: Saddle height (cm) = 7.41 + 0.82(inseam cm) - 0.1(minimum knee flexion °) + 0.003(inseam cm)(seat tube angle °). The maximum knee flexion equation (R²=0.97; RMSE=1.15 cm) was: Saddle height (cm) = 41.63 + 0.78(inseam cm) - 0.25(maximum knee flexion °) + 0.002(inseam cm)(seat tube angle °). The saddle height equations were not dependent on sex.

CONCLUSIONS

These equations provide a novel, practical strategy for bicycle-fit that accounts for rider anthropometrics, bicycle geometry and user-defined kinematics. HighlightsThis work developed simple equations to prescribed bicycle saddle height that elicits desired knee kinematics.Separate equations are presented for prescribing minimum or maximum knee flexion angle.Equations can be generalized to riders of both sexes, and a breadth of anthropometrics and ages.

Anthropometrics, flexibility and training history as determinants for bicycle configuration

Intrinsic factors such as leg length, arm length, flexibility and training history are factors that may be relevant to the optimisation of the individual bicycle configuration process. Bike fitting methods do not always take all these variables into account, and as yet there have been limited studies examining how these variables can affect the cyclist's position on the bicycle. The main aims of this study were to establish how individual anthropometrics, training history and flexibility may influence cyclists' freely chosen bicycle configuration, and to determine the full-body static flexion angles chosen by cyclists on the bicycle.

Fifty well-trained male cyclists were recruited for the study. A multivariate linear regression analysis was performed to predict the four main configurations of a bicycle (saddle height, saddle setback, handlebar reach and handlebar drop) based on individual anthropometrics, flexibility and training history. Average joint kinematic ranges for the knee (36°±7°) and elbow (19°±8°) joint supported previous recommendations. Hip (77°±5°) and shoulder (112°±7°) joint angles should be determined as true clinical joints.

Trochanteric leg length (p < 0.01), Knee Extension Angle test (p < 0.01) and mSchober test (p = 0.04) were significant predictors for determining saddle height. Hamstring flexibility can be used to predict handlebar drop (p = 0.01).

A cyclist who wishes to adopt a more aerodynamic position with an increased handlebar drop should aim to improve their hamstring flexibility.

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.

Physiological, biomechanical, and subjective effects of medio-lateral distance between the feet during pedalling for cyclists of different morphologies

Improper medio-lateral distance between the feet in cycling can increase the risk of injuries and decrease performance due to hip/knee/ankle misalignment in the frontal plane. The objective of this study was to measure the impact of pedal spacing changes during pedalling on the biomechanical, physiological, and subjective variables of people with different morphologies. Twenty-two cyclists were divided into two groups according to their pelvis width (narrow and wide). They performed four submaximal pedalling tests with different pedal spindle lengths (+20 mm, +40 mm, and +60 mm compared to the pedal spindle lengths of standard road bikes). EMG activity, 3D joint kinematics of the lower limbs, comfort, and perceived exertion were measured during each test. Moreover, gas exchange data were collected to measure gross mechanical efficiency and cycling economy. No significant differences in muscular activity or joint kinematics were observed among the four experimental conditions. However, gross mechanical efficiency, cycling economy, and perceived comfort significantly improved while perceived exertion significantly reduced with the narrowest pedal spacing for the whole population, as well as for the narrow and wide pelvis groups. Therefore, the lowest medio-lateral distance between the feet seems more suitable for comfort and performance improvement, irrespective of the individual's morphology.

Knee joint biomechanics of patients with unilateral total knee arthroplasty during stationary cycling

Stationary cycling is typically recommended following total knee arthroplasty (TKA) operations. However, knee joint biomechanics during cycling remains mostly unknown for TKA patients. Biomechanical differences between the replaced and non-replaced limb may inform applications of cycling in TKA rehabilitation. The purpose of this study was to examine the knee joint biomechanics of TKA patients during stationary cycling. Fifteen TKA participants cycled at 80 revolutions per minute and workrates of 80 W and 100 W while kinematics (240 Hz) and pedal reaction forces using a pair of instrumented pedals (1200 Hz) were collected. A 2x2 (limb × workrate) repeated measures ANOVA was run with an alpha of 0.05. Peak knee extension moment (KEM, p = 0.034) and vertical pedal reaction force (p = 0.038) were significantly reduced in the replaced limbs compared to non-replaced limbs by 21.3% and 5.3%, respectively. Peak KEM did not change for TKA patients with the increased workrate (p = 0.750). However, both peak hip extension moment (p = 0.009) and ankle plantarflexion moment (p = 0.017) increased due to increased workrate. Patients following TKA showed similar decreases in peak KEM and vertical pedal reaction force in their replaced compared to non-replaced limbs, as previously seen in gait. Patients of TKA may rely on their hip and ankle extensors to increases in workrate. Increasing intensity by 20 W did not exacerbate any inter-limb differences for peak KEM and vertical PRF.

Effects of a band loop on muscle activity and dynamic Knee valgus during pedaling

BACKGROUND

Change in the lower extremity alignments in the frontal plane and muscle activation patterns have been associated with lower extremity injuries. Therefore, to prevent injuries, many therapeutic protocols focus on find ways to correct dynamic knee valgus (DKV).

METHODS

Thirty-one recreational male cyclists with DKV (26.4 ± 4.5 years, 176.63 ± 7.51 cm, 75.81 ± 9.29 kg, 23.20 ± 4.15 kg/m2) volunteered to participate in this study. Simultaneous recordings of kinematic and electromyography data were performed on ten consecutive pedal cycles which began during the last 30 seconds of each four test condition: with band at 0.5 kg workload, with band at 2 kg workload, without band at 0.5 kg workload, and without band at 2 kg workload. The paired t-test was used for statistical analysis (p < 0.05).

RESULTS

The results indicated significant differences in VM (band = 0.029, no band = 0.031) and VL (band = 0.015, no band = 0.035) activation between workloads in each condition. Also there were significant differences in Gmed activation (0.5kg = 0.001, 2kg = 0.037), onset of Gmed (0.5kg = 0.048, 2kg = 0.012), offset of Gmed (0.5kg = 0.048, 2kg = 0.015), TFL activation (0.5kg = 0.001, 2kg = 0.041) and offset of TFL (0.5kg = 0.078, 2kg = 0.005) between the band and no band conditions. There was no different significant in VM/VL ratio between in each of four testing conditions (p > 0.05). The Gmed/TFL ratio was significantly greater in band condition than no band at both 0.5 (p = 0.045) and 2 kg (p = 0.001) workload. Knee abduction angle was affected by the band loop during the pedaling at two different workloads (0.5 kg: p = 0.047, 2 kg: p = 0.021) but mean (p = 0.027) and peak (p = 0.033) knee abduction angle significantly increased with increasing workload during the pedaling with band loop.

CONCLUSIONS

pedaling with the band loop can be considered as an effective method to increase the Gmed, Gmed/TFL ratio and control of DKV but increasing the workload during pedaling must be done with caution to prevent DKV.

Novel Method for the Manufacture of Complex CFRP Parts Using FDM-based Molds

Fibre-reinforced polymers (FRP) have attracted much interest within many industrial fields where the use of 3D printed molds can provide significant cost and time savings in the production of composite tooling. Within this paper, a novel method for the manufacture of complex-shaped FRP parts has been proposed. This paper features a new design of bike saddle, which was manufactured through the use of molds created by fused deposition modeling (FDM), of which two 3D printable materials were selected, polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS), and these molds were then chemically and thermally treated. The novel bike saddles were fabricated using carbon fiber-reinforced polymer (CFRP), by vacuum bag technology and oven curing, utilizing additive manufactured (AM) molds. Following manufacture the molded parts were subjected to a quality inspection, using non-contact three-dimensional (3D) scanning techniques, where the results were then statistically analyzed. The statistically analyzed results state that the main deviations between the CAD model and the manufactured CFRP parts were within the range of ±1 mm. Additionally, the weight of the upper part of the saddles was found to be 42 grams. The novel method is primarily intended to be used for customized products using CFRPs.

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.

Reproducibility of lower limb motion and forces during stationary submaximal pedalling using wearable motion tracking sensors

In order to address gaps in the literature, this study assessed the reproducibility (i.e., difference between and within sessions) of joint and muscle forces using wearable sensors during stationary cycling. Seventeen male cyclists performed two sessions on a cycle ergometer cycling at a combination of three power outputs (1.5, 2.5 and 3.5 W/kg) and three pedalling cadences (60, 80 and 100 rpm) in two sessions (2-7 days apart). The first trial from each session was repeated at the end of the session for assessment of within-session reproducibility. Three-dimensional (3D) full-body motion and 3D bilateral pedal forces were collected using an inertial motion tracking system and a pair of instrumented pedals, respectively. Joint angles, muscle forces and knee joint forces were computed using OpenSim. Poor to excellent agreement (ICCs = 0.31-0.99) was observed and differences were trivial to small and non-significant between trials within-session. Poor to excellent agreement (ICCs = 0.05-0.97) was observed and differences were trivial to large between sessions. Variability can be attributed to changes in muscle recruitment strategies (within and between-sessions) and to repositioning of sensors (between-sessions).

Vibrotactile feedback for correcting aerodynamic position of a cyclist

Guidance to maintain an optimal aerodynamic position is currently unavailable during cycling. This study used real-time vibrotactile feedback to guide cyclists to a reference position with minimal projected frontal area as an indicator of aerodynamic drag, by optimizing torso, shoulder, head and elbow position without compromising comfort when sitting still on the bike. The difference in recapturing the aerodynamic reference position during cycling after predefined deviations from the reference position at different intensities was analysed for 14 participants between three interventions, consisting of 1) vibrotactile feedback with a margin of error of 1.5% above the calibrated reference projected frontal area, 2) vibrotactile feedback with a margin of 3%, and 3) no feedback. The reference position is significantly more accurately achieved using vibrotactile feedback compared to no feedback (p < 0.001), but there is no significant difference between the 1.5% and 3% margin (p = 0.11) in terms of relative projected frontal area during cycling compared to the calibrated reference position (1.5% margin -0.46 ± 1.76%, 3% margin -0.01 ± 2.01%, no feedback 2.59 ± 3.29%). The results demonstrate that vibrotactile feedback can have an added value in assisting and correcting cyclists in recapturing their aerodynamic reference position.

Increased Q-Factor increases frontal-plane knee joint loading in stationary cycling

BACKGROUND

Q-Factor (QF), or the inter-pedal width, in cycling is similar to step-width in gait. Although increased step-width has been shown to reduce peak knee abduction moment (KAbM), no studies have examined the biomechanical effects of increased QF in cycling at different workrates in healthy participants.

METHODS

A total of 16 healthy participants (8 males, 8 females, age: 22.4 ± 2.6 years, body mass index: 22.78 ± 1.43 kg/m², mean ± SD) participated. A motion capture system and customized instrumented pedals were used to collect 3-dimensional kinematic (240 Hz) and pedal reaction force (PRF) (1200 Hz) data in 12 testing conditions: 4 QF conditions-Q1 (15.0 cm), Q2 (19.2 cm), Q3 (23.4 cm), and Q4 (27.6 cm)-under 3 workrate conditions-80 watts (W), 120 W, and 160 W. A 3 × 4 (QF × workrate) repeated measures of analysis of variance were performed to analyze differences among conditions (p < 0.05).

RESULTS

Increased QF increased peak KAbM by 47%, 56%, and 56% from Q1 to Q4 at each respective workrate. Mediolateral PRF increased from Q1 to Q4 at each respective workrate. Frontal-plane knee angle and range of motion decreased with increased QF. No changes were observed for peak vertical PRF, knee extension moment, sagittal plane peak knee joint angles, or range of motion.

CONCLUSION

Increased QF increased peak KAbM, suggesting increased medial compartment loading of the knee. QF modulation may influence frontal-plane joint loading when using stationary cycling for exercise or rehabilitation purposes.

The Association Between Pelvic Discomfort and Erectile Dysfunction in Adult Male Bicyclists

BACKGROUND

Bicycle riding's impact on erectile function remains a topic of great interest given cycling's popularity as a mode of transportation and exercise.

AIM

We evaluated risk factors for sexual dysfunction in male cyclists with the primary intention of determining if genital/pelvic pain and numbness are associated with erectile dysfunction (ED).

METHODS

We surveyed male cyclists using an online anonymous questionnaire. Cyclists were queried on their demographics, cycling experience, and sexual function using the Sexual Health Inventory for Men (SHIM). ED was diagnosed when a completed SHIM score was <22. Regression analysis was used to evaluate the risk of ED in men with genital/pelvic pain or numbness after riding. The survey was designed in the United States.

OUTCOMES

Quantitative characterization of cycling habits, onset and timing of genital pain and numbness, and SHIM score.

RESULTS

A total of 1635 participants completed the survey. A majority of men were over the age of 50 (58%, 934/1,607), Caucasian (88%, 1,437/1,635), had been active cyclists for over 10 years (63%, 1,025/1,635) and used road bikes (97%, 1,578/1,635). Overall, 22%, 30%, and 57% of men reported ED, genital pain, and genital numbness, respectively. While controlling for cohort demographics, body mass index, cycling intensity and equipment, and medical comorbidities, no saddle characteristics were associated with the risk of developing genital numbness. However, men reporting penile numbness were at higher risk of reporting ED (odds ratio [OR] = 1.453, P = .048). In addition, quicker onset of numbness and resolution of numbness within a day was associated with impaired erectile function. For example, numbness occurring less than 1 hour after cycling had greater odds of leading to ED than numbness after 5 hours (OR = 2.002, P = .032). Similarly, genital pain occurring less than 1 hour (OR = 2.466, P = .031) after cycling was associated with higher ED risk.

STRENGTHS & LIMITATIONS

Strengths include a large sample size of high-intensity cyclists and validated questionnaire use. Limitations include reliance on anonymous self-reported survey data and minimal inquiry into the riding preferences and terrain traversed by cyclists.

CONCLUSIONS

Pelvic pain and numbness are common complaints among male riders in the United States. Men with such complaints are more likely to also report ED especially if it occurs earlier in the ride. Although direction of causality and temporality are uncertain, alleviation of factors resulting in pelvic discomfort may reduce cycling's impact on sexual function. Such interventions are critical given that cycling for both active travel and aerobic exercise confers numerous health benefits. Balasubramanian A, Yu J, Breyer BN, et al. The Association Between Pelvic Discomfort and Erectile Dysfunction in Adult Male Bicyclists. J Sex Med 2020;17:919-929.

Cycling Biomechanics Optimization-the (R) Evolution of Bicycle Fitting

Optimal bicycle configuration has been the topic of numerous studies. A majority of these have investigated the optimal saddle height and have used either static kinematics or two-dimensional kinematic measurements. Other joints, such as the hip, shoulder, and elbow joint, have not been investigated to any meaningful extent. There is, therefore, a paucity of data describing the optimal position of the upper body and pelvis in cycling. More recently, it has been recommended that bike fitting be conducted in a dynamic functional manner, as kinematics can be influenced by cycling workload. Full-body three-dimensional kinematics and saddle pressure are newer modalities available to the clinician. This review of the literature investigates the current research pertaining to the configuration of all components of the bicycle, from static methods to dynamic methods, and related to optimal performance and injury prevention. Setting the saddle height using the Holmes static method is optimal for injury prevention and performance. Guidelines for optimal bicycle configuration should take into account the training intensity when assessing kinematics as compensatory lower-limb kinematics occur during higher-power outputs. Optimal KFA using dynamic measurements should range from 33° to 43° at low intensity to 30° to 40° at high intensity when measured at the bottom dead center crank position. Saddle pressure mapping should ideally be performed at an intensity similar to what cyclists will encounter during the majority of their training and racing. Reference values and recommendations for dynamic assessments are still required for all other joints. Furthermore, intrinsic factors, such as training load and flexibility, which may affect bicycle configuration and performance, should be investigated to assess how these may influence the optimal bicycle configuration.

THE ROLE of a BIKE FIT in CYCLISTS with HIP PAIN. A CLINICAL COMMENTARY

Hip pathology is common amongst athletes and the general population. The mechanics of cycling have the potential to exacerbate symptomatic hip pathology and progress articular pathology in patients with morphologic risk factors such as femoroacetabular impingement. A professional fit of the bicycle to the individual which aims to optimize hip joint function can allow patients with hip pathology to exercise in comfort when alternative high impact exercise such as running may not be possible. Conversely improper fit of the bicycle can lead to hip symptoms in otherwise healthy individuals who present with risk factors for hip pain. Accordingly a bike fit can form part of the overall management strategy in a cyclist with hip symptoms. The purpose of this clinical commentary is to discuss hip pathomechanics with respect to cycling, bicycle fitting methodology and the options available to a physical therapist to optimize hip mechanics during the pedaling action.

Cycling: joint kinematics and muscle activity during differing intensities

Full body kinematics and electromyographic (EMG) patterns may alter based on the workloads that are encountered during cycling. Understanding the effect of differing intensities on the cyclist can guide clinicians and bike fitters in improving specific muscle strength and cycling posture to optimise training and racing. We aimed to assess changes in lower limb EMG magnitudes and full body 3D kinematics of 17 well-trained cyclists at three different exercise intensities: 60%, 80% and 90% of maximum heart rate. Significant results were demonstrated for all the joints except the hip and shoulder. Cyclists' ankle dorsiflexion and knee extension increased between 6% and 9% with higher intensities. The elbow adopted a significantly more flexed position, increasing flexion by 39% from 60% to 90% intensity, whilst the lumbar and thoracic flexion increased by 7% at the higher intensity. There were significant increases in EMG signal amplitude at higher intensities for all muscle groups measured. These results will guide clinicians in strengthening specific muscles at specific ranges of the cycling pedal revolution. Guidelines for optimal bicycle configuration should take into account the full body position of the cyclist as well as the training and racing intensity when assessing kinematics.

Changes in body position on the bike during seated sprint cycling: Applications to bike fitting

Dynamic bike fitting often includes the optimisation of lower limb joint kinematics while participants undertake sub-maximal intensity cycling; however, this practice might not be appropriate for sprint cycling. This study aimed to determine if trained cyclists maintain lower limb angles, defined during dynamic sub-maximal bike fitting, while completing seated sprint cycling. Fifteen competitive cyclists completed two testing sessions. Dynamic bike fitting was undertaken during the first session, where handlebar positions were identified to produce pre-determined hip flexion angles (70°-110°) during sub-maximal cycling using an inertial-based motion tracking system. In the second session, full body kinematics were determined during two 6-s sprints performed at each of the pre-determined handlebar positions. During sprinting, measured right hip angles were only different at 110°, when compared with 90° (p < 0.01, d = 0.95), and 80° (p < 0.01, d = 1.49). For the left leg, measured hip angles differed between 110° vs. 90° (p < 0.01, d = 1.52), 110° vs. 80° (p < 0.01, d = 2.09), and 100° vs. 80° (p = 0.04, d = 1.06). Even though changes in bike configuration resulted in 10° increments of hip flexion during dynamic sub-maximal bike fitting, these hip angles were not replicated during sprinting. Therefore, dynamic sub-maximal bike fitting leading to changes in handlebar positions that produce hip angles of 80°-100° might not influence cycling performance due to acute changes in the body position of cyclists on the bicycle during a sprint.

Biomechanical and physiological responses to electrically assisted cycling during simulated mail delivery

This study quantified the biomechanical (movements and forces) and physiological (energy expenditure) demands of postal delivery performed with electrically assisted bicycles (EABs). Ten postal workers and 10 recreational athletes performed three simulated postal tasks (simulated mail delivery circuit, delivery distance [close vs. far], and 3-min stationary cycling) while carrying 0, 16 and 32 kg. Physiological (energy expenditure) and biomechanical (internal and external forces and joint angles) responses were calculated. Energy expenditure (10-20%; p < 0.05) and power output (30-44%; p < 0.05) increased with increasing mail loads. Ground reaction force increased (∼10%) for the far delivery distance, but joint reaction forces were unchanged. Lower hip flexion (p < 0.01), less hip abduction (p < 0.01) and larger spine anterior flexion (p < 0.01) were observed for the far delivery distance. Joint forces were not affected by the mail load transported (0-32 kg) or distance from the mailbox (close vs far). EABs can provide a suitable transportation method to assist mail delivery in terms of energy expenditure reduction.

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.

Physiological, kinematic, and electromyographic responses to kinesiology-type patella tape in elite cyclists

Kinesiology-type tape (KTT) has become popular in sports for injury prevention, rehabilitation, and performance enhancement. Many cyclists use patella KTT; however, its benefits remain unclear, especially in uninjured elite cyclists. We used an integrated approach to investigate acute physiological, kinematic, and electromyographic responses to patella KTT in twelve national-level male cyclists. Cyclists completed four, 4-minute submaximal efforts on an ergometer at 100 and 200 W with and without patella KTT. Economy, energy cost, oxygen cost, heart rate, efficiency, 3D kinematics, and lower-body electromyography signals were collected over the last minute of each effort. Comfort levels and perceived change in knee stability and performance with KTT were recorded. The effects of KTT were either unclear, non-significant, or clearly trivial on all collected physiological and kinematic measures. KTT significantly, clearly, and meaningfully enhanced vastus medialis peak, mean, and integrated electromyographic signals, and vastus medialis-to-lateralis activation. Electromyographic measures from biceps femoris and biceps-to-rectus femoris activation ratio decreased in either a significant or clinically meaningful manner. Despite most cyclists perceiving KTT as comfortable, increasing stability, and improving performance, the intervention exerted no considerable effects on all physiological and kinematic measures. KTT did alter neuromuscular recruitment, which has potential implications for injury prevention.

The effect of saddle height and saddle position changes from pedal on muscles and joints behaviors in ergometer: A parametric study

The physical activities such as pedaling can affect the lower limb muscles strength and rehabilitation. Improper pedaling can cause injury. In this study, we would investigate the effects of saddle place (saddle position and saddle height) on the behavior of muscles and joints. Moreover, we would try to reveal the relationship between the muscles activity (Act) and the joints reaction forces ( F) and saddle position and saddle height. To this end, the pedaling conditions are obtained from the biomechanical model of the human movement system presented in AnyBody software. The variations in 12 muscles Act and total, normal and shear F of ankle, knee and hip joints are studied for the various saddle places in the pedaling feasible range. The relationships of those muscles Act and joints F are predicted by the response surface method. The results indicate that the muscles and the joints behavior changes for various saddle position and saddle height. The maximum and the minimum of the total response are acquired in the ankle and hip joints, respectively. In contrast to the ankle and hip joints, the knee shear response is greater than the normal response. The predictive models of the muscles Act and the joints F (the regression coefficients ( R2) are 0.60–0.95 and 0.76–0.97, respectively) indicate their nonlinear behavior with saddle position and saddle height variations. Studying the muscles and joints behavior in different pedaling condition can be helpful for the suitable saddle placement in order for rehabilitation, muscles soreness reduction, and joints disorder treatment.

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.

Potential factors associated with knee pain in cyclists: a systematic review

The potential factors associated with overuse injuries and pain in cyclists that are supported by evidence remain unclear. Our study aimed at assessing, using a systematic search of the most updated evidence, the main factors related to overuse knee-related pain and/or injuries in cyclists. The search assessed any potential mechanism related to knee pain or injury that could be used in the clinical practice. Databases were searched (i.e., PubMed, Scopus, Web of Science, and EBSCO). Studies were included if they presented results from original studies. They had to include, preferably but not limited to, recreational and/or competitive cyclists with or without knee pain. Quality of articles was assessed. Eleven articles were deemed eligible for full text appraisal. Studies involved generally the assessment of biomechanical outcomes associated with knee pain in cyclists. Overall, studies showed that cyclists with knee pain present larger knee adduction and larger ankle dorsiflexion and differences in activation for hamstrings and quadriceps muscles. Unclear results were observed for knee moments and no differences were observed for knee flexion angle, tibiofemoral and patellofemoral forces. It is important to state that varied types of knee pain were mixed in most studies, with 2 focused on anterior-related pain. Cyclists with overuse-related pain or injuries on their knees presented an increased medial projection of their knees and an altered activation of the Vastus Medialis and Vastus Lateralis muscles. However, this limited evidence is based on retrospective studies comparing cyclists with and without pain, which limits the conclusion on how cyclists develop knee pain and what are the main options for treatment of knee pain.

Low-level laser therapy improves the VO2 kinetics in competitive cyclists

Some evidence supports that low-level laser therapy (LLLT) reduces neuromuscular fatigue, so incrementing sports performance. A previous randomized controlled trial of our group showed increased exercise tolerance in male competitive cyclists treated with three different LLLT doses (3, 6, and 9 J/diode; or 135, 270, and 405 J/thigh) before time-to-exhaustion cycling tests. Now, the present study was designed to evaluate the effects of these LLLT doses on the VO₂ kinetics of athletes during cycling tests. Twenty male competitive cyclists (29 years) participated in a crossover, randomized, double-blind, and placebo-controlled trial. On the first day, the participants performed an incremental cycling test to exhaustion to determine maximal oxygen uptake (VO_2MAX) and maximal power output (PO_MAX), as well as a familiarization with the time-to-exhaustion test. In the following days (2 to 5), all participants performed time-to-exhaustion tests at PO_MAX. Before the exhaustion test, different doses of LLLT (3, 6, and 9 J/diode; or 135, 270, and 405 J/thigh, respectively) or placebo were applied bilaterally to the quadriceps muscle. All exhaustion tests were monitored online by an open-circuit spirometry system in order to analyze the VO₂ amplitude, VO₂ delay time, time constant (tau), and O₂ deficit. Tau and O₂ deficit were decreased with LLLT applications compared to the placebo condition (p < 0.05). No differences (p > 0.05) were found between the experimental conditions for VO₂ amplitude and VO₂ delay time. In conclusion, LLLT decreases tau and O₂ deficit during time-to-exhaustion tests in competitive cyclists, and these changes in VO₂ kinetics response can be one of the possible mechanisms to explain the ergogenic effect induced by LLLT.