EFFECT OF HOLD SLOPER ANGLE AND HOLD DEPTH ON MAXIMAL FINGER FORCE CAPACITY OF ROCK CLIMBERS

The purpose of this study was to identify the combined effect of sloper angle and hold depth on maximal finger force capacity (MFFC) of rock climbers. Eight experienced climbers performed vertical maximal finger contractions on four different size of holds (1, 2, 3 and 4 cm) with five different sloper angles from 0° to 40° (with 10° increment). The results of this study showed that mean MFFC ranged from 25.2 ± 4.1 kg to 49.1 ± 9.0 kg and differed significantly according to the sloper angle and hold depth. Besides, decreasing the hold depth and increasing the sloper angle of a hold leads to a fall of the MFFC. These results confirm the previous findings of hold depth effect and improve them for sloper holds by pointing out the interaction between hold depth and slope angle

BIOMECHANICS OF THE SINGLE-HANDED DYNAMIC MOVES ON CAMPUS BOARD AND EFFECT OF RUNG DISTANCE

The purpose of this study was to gain an insight into the kinematics and kinetics of the single-handed dynamic moves on campus board and investigate the effects of increased rung distance on biomechanical parameters. Eight climbers, six males and two females, performed various single-handed dynamic moves on an instrumented campus board. Kinematic and kinetic data were collected during each jumping move. The results showed that duration of acceleration and flight phases increased and duration of control phase decreased with increasing target distance. The reaction force on the starting rung in acceleration phase and the reaction force on target rung were found increasing with increasing target distance

EFFECTS OF PATELLAR TENDON STRAP ON ELECTROMYOGRAPHIC ACTIVITY OF QUADRICEPS MUSCLES DURING DROP LANDING

The purpose of this study was to clarify how patellar tendon strap affects on electromyographic activity of quadriceps muscles during drop landing. Four healthy male athlete participants made three drop landings with/without strap and acceptable landing trials were analysed. There was a marginal delay for vastus lateralis onset timing for strapping condition and this may be one of the main contributions of strapping for decreasing knee pain during athletic activities

Comparative grading scales, statistical analyses, climber descriptors and ability grouping: International Rock Climbing Research Association position statement

The research base for rock climbing has expanded substantially in the past 3 decades as worldwide interest in the sport has grown. An important trigger for the increasing research attention has been the transition of the sport to a competitive as well as recreational activity and the potential inclusion of sport climbing in the Olympic schedule. The International Rock Climbing Research Association (IRCRA) was formed in 2011 to bring together climbers, coaches and researchers to share knowledge and promote collaboration. This position statement was developed during and after the 2nd IRCRA Congress which was held in Pontresina, in September 2014. The aim of the position statement is to bring greater uniformity to the descriptive and statistical methods used in reporting rock climbing research findings. To date there is a wide variation in the information provided by researchers regarding the climbers’ characteristics and also in the approaches employed to convert from climbing grading scales to a numeric scale suitable for statistical analysis. Our paper presents details of recommended standards of reporting that should be used for reporting climber characteristics and provides a universal scale for the conversion of climbing grades to a number system for statistical analysis

Kaya Tırmanışında Tutamak Yapılarına Göre Tutuş Zorluk Derecelerinin Modellenmesi

The aims of this study were to analyze the effects of grip techniques, hold depth and hold inclination on maximal finger force capacity (MFFC) and muscle fatigue in order to develop a hold difficulty model related to these parameters. For these purposes, three consecutive studies were conducted. In the first study, the relationship between hold depth, grip technique and MFFC were examined and it was concluded that MFFC falls with the decrease in hold depth. In the second study, the effects of hold depth on intermittent finger force endurance were examined and it was seen that there is an excessive and sharp decline on 1 cm depth hold. In the third study, the effects of hold surface inclination on MFFC were analysed on various depths of holds. The results showed that MFFC decreases with the increase in the hold surface inclination and this decline is more notable on narrow holds. The results of all these three studies were combined and a hold difficulty model was created.Bu çalışmada, farklı tutuş teknikleri, tutamak derinlikleri ve tutamak yüzey açılarında tırmanıcıların uygulayabildikleri maksimal parmak kuvveti kapasiteleri ve yorgunluk ilişkileri incelenerek tutamaklar ve tutuşlar için bu değişkenlere bağlı bir zorluk fonksiyonu ve modeli oluşturulması amaçlanmıştır. Bu bağlamda birbirini takip eden üç farklı çalışma yapılmıştır. İlk çalışmada, tutamak derinliği ve tutuş tekniklerinin maksimal parmak kuvvet kapasitesi (MPKK) üzerindeki etkileri araştırılmış ve derinliğin azalması ile MPKK nın azaldığı bulunmuştur. İkinci çalışmada tutamak derinliği ile tekrarlı izometrik parmak kuvveti dayanıklılığı arasındaki ilişki incelenmiştir. Derinliği 1 cm olan tutamakta kuvvet kapasitesinde daha fazla ve keskin düşüş olduğu görülmüştür. Üçüncü çalışmada, hem tutamak derinliği hem de yüzey açısı değiştirilerek MPKK incelenmiştir. Oluşturulan MPKK kestirim fonksiyonları ile tutamak tutuş zorluğununun tanımlanmasında yeni modeller önerilmiştir

The effect of chalk on the finger-hold friction coefficient in rock climbing

International audienceThe main purpose of this study was to examine the effect of chalk on the friction coefficient between climber's fingers and two different rock types (sandstone and limestone). The secondary purpose was to investigate the effects of humidity and temperature on the friction coefficient and on the influence of chalk. Eleven experienced climbers took part in this study and 42 test sessions were performed. Participants hung from holds which were fixed on a specially designed hang board. The inclination of the hang board was progressively increased until the climber's hand slipped from the holds. The angle of the hang board was simultaneously recorded by using a gyroscopic sensor and the friction coefficient was calculated at the moment of slip. The results showed that there was a significant positive effect of chalk on the coefficient of friction (+18.7% on limestone and +21.6% on sandstone). Moreover sandstone had a higher coefficient of friction than limestone (+15.6% without chalk, +18.4% with chalk). These results confirmed climbers' belief that chalk enhances friction. However, no correlation with humidity/temperature and friction coefficient was noted which suggested that additional parameters should be considered in order to understand the effects of climate on finger friction in rock climbing

Effect of hold depth and grip technique on maximal finger forces in rock climbing

International audienceThe aim of this study was to understand how the commonly used climbing-specific grip techniques and hold depths influence the finger force capacities. Ten advanced climbers performed maximal voluntary force on four different hold depths (from 1 to 4 cm) and in two force directions (antero-posterior and vertical) using three grip techniques (slope, half crimp and full crimp). A specially designed platform instrumented with a 6-degrees-of-freedom (DoF) force/torque sensor was used to record force values. Results showed that the maximal vertical forces differed significantly according to the hold depth and the grip technique (ranged from 350.8 N to 575.7 N). The maximal vertical forces increased according to the hold depth but the form of this increase differed depending on grip technique. These results seemed to be more associated with finger-hold contact/interaction than with internal biomechanical factors. Similar results were revealed for antero-posterior forces (ranged from 69.9 N to 138.0 N) but, it was additionally noted that climbers have different hand-forearm posture strategies with slope and crimp grip techniques when applying antero-posterior forces. This point is important as it could influence the body position adopted during climbing according to the chosen grip technique. For trainers and designers, a polynomial regression model was proposed in order to predict the mean maximal force based on hold depth and adopted grip technique

Improved accuracy of biomechanical motion data obtained during impacts using a time-frequency low-pass filter

Biomechanical motion data involving impacts are not adequately represented using 31 conventional low-pass filters (CF). Time-frequency filters (TFF) are a viable alternative, but 32 have been largely overlooked by movement scientists. We modified Georgakis and 33 Subramaniam’s (2009) fractional Fourier filter (MFrFF) and demonstrated it performed better 34 than CFs for obtaining lower leg accelerations during football instep kicking. The MFrFF 35 displayed peak marker accelerations comparable to a reference accelerometer during foot-to-36 ball impact (peak % error = -5.0 ± 11.4%), whereas CFs severely underestimated these peaks 37 (30 - 70% error). During the non-impact phases, the MFrFF performed comparably to CFs 38 using an appropriate (12 - 20Hz) cut-off frequency (RMSE = 37.3 ± 7.6 m/s2 vs. 42.1 ± 11.4 39 m/s2, respectively). Since accuracy of segmental kinematics is fundamental for understanding 40 human movement, the MFrFF should be applied to a range of biomechanical impact scenarios 41 (e.g. locomotion, landing and striking motions) to enhance the efficacy of study in these areas

Choice of low-pass filter influences practical interpretation of ball kicking motions : the effect of a time-frequency filter method

When studying ball kicking, conventional low-pass filters may distort kick leg kinematics near the time of foot-to-ball contact, leading to flawed practical interpretation of the skill. Time-frequency filters are a viable alternative, but are not widely used. This study compared a fractional Fourier filter (FrFF) with conventional filters (CF) methods for estimating common parameters used to define kicking performance. Instep kicks from 23 experienced soccer players were captured by 3D motion analysis (1000Hz), and kick leg foot velocities, knee angular velocities and ankle dorsi-plantarflexion angles compared between the FrFF and variations of a Butterworth CF. The FrFF and CFs using a higher cut-off frequency (> 70 Hz) successfully detected lower leg motion prior to, during and following impact, whereas CFs with low cut-off frequencies (< 20Hz) attenuated motion near impact. Truncating data at impact provided valid pre-impact kinematics, but ignored information thereafter. Rather than decelerating the lower leg to conserve accuracy, ‘kicking through the ball’ should be considered a valid coaching cue. Further, controlling ankle plantarflexion to ensure efficient impact mechanics may be important for skilled kicking. Practitioners should consider how choice of filter will affect their data, and use of time-frequency methods can help inform empirically grounded coaching practices

Comparative grading scales, statistical analyses, climber descriptors and ability grouping: International Rock Climbing Research Association position statement

International audienceThe research base for rock climbing has expanded substantially in the past three decades as worldwide interest in the sport has grown. An important trigger for the increasing research attention has been the transition of the sport to a competitive as well as recreational activity and the potential inclusion of sport climbing in the Olympic schedule. The International Rock Climbing Research Association (IRCRA) was formed in 2011 to bring together climbers, coaches and researchers to share knowledge and promote collaboration. This position statement was developed during and after the 2nd IRCRA Congress which was held in Pontresina, in September 2014. The aim of the position statement is to bring greater uniformity to the descriptive and statistical methods used in reporting rock climbing research findings. To date there is a wide variation in t he information provided by researchers regarding the climbers' characteristics and also in the approaches employed to convert from climbing grading scales to a numeric scale suitable for statistical analysis. Our paper presents details of recommended standards of reporting that should be used for reporting climber characteristics and provides a universal scale for the conversion of climbing grades to a number system for statistical analysis