Kinematic Variables Evolution During a 200-m Maximum Test in Young Paddlers

Kinematic and neuromuscular responses to different visual focus conditions in stand-up paddleboarding

Purpose

This study analyzed the kinematics and muscle activity during the stand-up paddleboarding (SUP) under different visual focus points in three conditions: i) eyes on the board nose, ii) looking at the turn buoy, and iii) free choice.

Methods

Fourteen male paddleboarders (24.2 ± 7.1 years) performed three trials covering 65 m, and the electromyographic (EMG) activation patterns and kinematic parameters in four cycle strokes for the left and right sides were analyzed. Surface EMG of the upper trapezius, biceps brachii, triceps brachii, tibialis anterior, and gastrocnemius medialis were recorded. The data were processed according to the percentage of maximum voluntary contraction (%MVC). Speed, stroke frequency (SF), stroke length, and stroke index (SI) were analyzed.

Results

The speed, SF, and SI (p < 0.01, η2 ≥ 0.42) showed significant variance between conditions, with the free condition achieving the highest speed (1.20 ± 0.21 m/s), SF (0.65 ± 0.13 Hz) and SI (2.25 ± 0.67 m2/s). This condition showed greater neuromuscular activity, particularly in the triceps brachii during both the left (42.25 ± 18.76 %MVC) and right recoveries (32.93 ± 16.06 %MVC). During the pull phase, the free choice presented higher biceps brachii activity (8.51 ± 2.80 %MVC) compared to the eyes on the board nose (6.22 ± 2.41 %MVC; p < 0.01), while showing lower activity in the triceps brachii (10.02 ± 4.50 %MVC vs. 16.52 ± 8.45 %MVC; p < 0.01) and tibialis anterior (12.24 ± 7.70 %MVC vs. 17.09 ± 7.73 %MVC; p < 0.01) compared to looking at the turn buoy.

Conclusion

These results suggest that a free visual focus allows paddleboarders to enhance their kinematics and muscle activation, highlighting the significance of visual focus strategies in improving both competitive and recreational SUP performance.

Steadiness of technical variables as a determinant factor of performance in a virtual simulated regatta

The aim of this investigation is to explore the relationship between Optimist sailing performance with boat steadiness as well as the steadiness of cyclic variables related to sailors' technique, in the upwind leg of a regatta. Thirty-two sailors from the optimist class (16 bottom level and 16 top level) performed a regatta in a semi-immersive simulator which measures the instantaneous velocity, heading, boom, heel, and rudder angle and hiking effort. It was calculated the mean values as well as the short-term steadiness and long-term steadiness throughout the test. Top level and bottom level sailors were compared and the correlation between these variables and mean velocity were analysed. Significant differences were found between groups on mean values, STS values and LTS values as well as significant correlations ranging r values between 0.385 and 0.768. If the steadiness of sailing variables is considered, they appear as determinants of performance in Optimist class while this is not observed when analysing mean values.

Inter-stroke steadiness: a new kinematic variable related to 200m performance in young canoeists

Traditionally, canoeing analyses have always been carried out by calculating mean values over a certain distance. However, a simple analysis of mean values in cyclic actions, such as canoe paddling, can lead to the loss of decisive data. Therefore, the objective of this study was to investigate whether the relationship between the periods of consecutive strokes can be an important aspect in all-out 200-m canoeing performance. A total of 22 young male canoeists aged 13.51 ± 0.43 years old voluntarily participated in the present study. Lateral recordings were taken from all participants when performing an all-out 200 m to subsequently analyse the kinematic variables of time, speed and cycle frequency, length and index. The time of each stroke was calculated by the frame differencesbetween two successive paddles. Likewise, short-term and long-term steadiness of consecutive strokes were analysed. Positive correlations were observed between all-out 200-m time and inter-stroke steadiness, identifying significant associations with long-term (r ≈ 0.8; p < 0.05) and short-term steadiness (r ≈ 0.7; p < 0.05). In conclusion, the present investigation defines and identifies inter-stroke steadiness as a new original kinematic variable that might be considered for performance analysis since it seems to be a key factor in all-out 200-m canoeing.

Validation of a global positioning system with accelerometer for canoe/kayak sprint kinematic analysis

This study aimed to validate the use of a Global Positioning System with an accelerometer (GPS-Acc) unit to quantify canoeing kinematic variables. Eight canoe and kayak (200 and 500 m) sprint races were analysed. All the races were recorded sideways by a digital camera that followed the kayak or canoe bow and simultaneously using a GPS-Acc unit recorded the data concerning boat position, velocity, and acceleration. In 200 m races, 50 m splits were established over the entire race distance. In 500 m races, 100 m splits were used, excepting the race start and end, where the splits were divided into two sections of 50 m. The data of the GPS-Acc unit were analysed using a self-developed routine. The agreement between the video and the GPS-Acc analysis was measured regarding all the variables by a Bland-Altman analysis. No differences were found between both methodologies, except for time and velocity at the first 50 m, suggesting thus an agreement between the analysis methods. The GPS-Acc unit is valid for measuring quickly and accurately kinematic variables, mainly boat velocity and stroke rate. However, video analyses may be necessary when a more detailed analysis of the paddling technique is of interest.

Performance Trajectory Related to Age, Classification, and Sex in Elite Kayak Para Canoe Athletes

OBJECTIVE

The aim of the study is to verify the performance trajectory related to age, classification (KL: kayak level; M: male; F: female), and sex of elite kayak Para canoe athletes.

DESIGN

This is a retrospective cohort study.

RESULTS

Race results and athletes' data were retrieved from publicly available online databases for 17 competitions and 102 finals between 2015 and 2022. Race time reduced over the years except for KL3-M class. There was a reduction in the relative difference between KL2-M and KL3-M over the years ( r = -0.83, 95% confidence interval = -0.34 to -0.97, P ≤ 0.05). In addition, no significant differences were found in race times relative differences between KL2-F and KL3-F over the years. Although the correlation between age and performance was only found to be statistically significant in the KL3-F class, the ages of all classes (35.2, 32.6, 29.5, 34.6, 37.6, and 30.6 yrs for males and females KL1, KL2, and KL3, respectively) were higher than those in Olympic canoeing (27.8 yrs).

CONCLUSIONS

Race times have improved overall since 2015, but not for the KL3-M class. Nevertheless, because of the stochastic ages of the finalist athletes, it was not possible to determine the age at which peak performance is achieved in all classes. Kayak Para canoe classes should be monitored in the coming years to determine whether interventions are necessary to improve differentiation.

Quantifying Paddling Kinematics through Muscle Activation and Whole Body Coordination during Maximal Sprints of Different Durations on a Kayak Ergometer: A Pilot Study

Paddling technique and stroke kinematics are important performance factors in flatwater sprint kayaking and entail significant energetic demands and a high strength from the muscles of the trunk and upper limbs. The various distances completed (from 200 m to 1000 m) require the athletes to optimize their pacing strategy, to maximize power output distribution throughout the race. This study aimed to characterize paddling technique and stroke kinematics during two maximal sprints of different duration. Nine nationally-trained participants (2 females, age: 18 ± 3 years; BMI: 22.2 ± 2.0 Kg m-1) performed 40 s and 4 min sprints at maximal intensity on a kayak ergometer. The main findings demonstrated a significantly greater mean stroke power (237 ± 80 W vs. 170 ± 48 W; p < 0.013) and rate (131 ± 8 spm vs. 109 ± 7 spm; p < 0.001) during the 40 s sprint compared to the 4 min sprint. Athletes used an all-out strategy for the 40 s exercise and a parabolic-shape strategy during the 4 min exercise. Despite the different strategies implemented and the higher muscular activation during the 40 s sprint, no change in paddling technique and body coordination occurred during the sprints. The findings of the present study suggest that the athletes constructed a well-defined profile that was not affected by fatigue, despite a decrease in power output during the all-out strategy. In addition, they regulated their paddling kinematics during the longer exercises, with no change in paddling technique and body coordination.

Whole-body kinematics during a simulated sprint in flat-water kayakers

Success in sprint kayaking depends on the propulsive power generated by trunk, pelvis, shoulder and lower limb movements. However, no studies have examined whole-body kinematics over a simulated distance. We aimed to study the changes in movement patterns of kayakers performing a 500-m kayak sprint. Eleven young K1 sprint kayakers (three females; age: 16.5 ± 1.9 years, height: 174.1 ± 7.1 cm and weight: 66.1 ± 6.2 kg) performed an incremental test on a kayak ergometer to assess their Peak Oxygen Uptake (V̇O_2peak). They then performed a 500-m sprint trial on the same ergometer, and the positions of 40 reflective markers were recorded to assess whole-body kinematics. Joint angles over time were computed for the trunk and right shoulder, hip, knee, and ankle. Changes of joint kinematics during the test were assessed with Statistical Parametric Mapping, calculating at each time node the linear regression between joint angles waveforms and the time of the rowing cycle, p < .05. Cardiometabolic responses confirmed that the participants achieved a maximal effort (V̇O₂ and HR reached 99 ± 11% and 94 ± 6% of peak values, respectively). Paddle velocity negatively correlated with sprint time. The shoulder (elevation, rotation and flexion), trunk (lateral flexion and rotation) and hip (abduction) angles significantly changed over time in different phases of the stroke cycle during the simulated sprint. No significant differences over time were found for knee and ankle flexion. A high-intensity sprint may affect the shoulder, trunk and hip kinematics of kayak paddling. The kinematic analysis of kayakers' paddling during simulated metabolic-demanding tasks can provide useful insights to coaches and athletes.