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ISBS 2024 CONFERENCE PROCEEDINGS TITLE AND FOREWARD
Get PDFThe ISBS is an international society totally dedicated to biomechanics in sports, whose primary purposes are: To provide a forum for the exchange of ideas for sports biomechanics researchers, coaches and teachers. To bridge the gap between researchers and practitioners. To gather and disseminate information and materials on biomechanics in sports.
Papers underwent a double blinded review process. Each paper in these proceedings has been reviewed by at least two members of the scientific committee
EFFECTS OF DYNAMIC KNEE VALGUS ALIGNMENT ON GROUND REACTION FORCE AND KNEE MOMENT DURING LANDING
Get PDFThis study examined the impact of dynamic knee valgus alignments on vertical ground reaction force(vGRF) and knee moment in 33 male collegiate athletes during a single-leg vertical jump from a 30-cm box. Categorized into valgus (n=12), neutral (n=8), and varus (n=13) groups based on knee angular displacement during landing, participants were analyzed 100 milliseconds immediately after initial ground contact. Normalized results indicate that the varus group demonstrated higher peak vGRF and maximum knee moment compared to the valgus and neutral groups. No significant differences were found in parameters like time to peak vGRF, loading rate, and peak hip moment. Our findings highlight the exacerbating effect of dynamic knee varus on landing impact, providing crucial insights for clinical applications and future research
CHARACTERISTICS OF TURN PERFORMANCE IN ELITE BREASTSTROKE SWIMMERS
Get PDFThe purpose of this study was to investigate relationships between the breaststroke turn phase time and movement during the turn phase in male competitive swimmers. The participants were six male breaststroke swimmers. All subjects performed three 100 m breaststroke trials with a push start, and the trial with the shortest time was selected for analysis. The swimmers were filmed using four cameras, and kinematic variables during the turn phase were calculated using two-dimensional analysis. The total turn time was 8.96 ± 0.20 s, and the 5 m RTT was 5.60 ± 0.13 s. Significant negative correlations were found between total turn time and distance at the point of first kick (4.99 ± 0.88 m) (r = -0.818, p = 0.047). All variables demonstrating significant correlations with distance at the point of first kick were associated with the pullout phase, except for push-off horizontal velocity. This suggests that both the push-off horizontal velocity and the pullout phase following the open turn play crucial roles in the turn performance of elite swimmers
STUDY ON THE INFLUENCE OF MIDSOLE HARDNESS AND SURFACE TYPE ON LOADING RATE IN HEEL-STRIKE RUNNERS
Get PDFHigh loading impact (LI) associated with heel strikes causes running injuries. This study aimed to investigate how midsole hardness and surface type affect LI. 12 runners ran at a fixed speed along an 18m runway with different midsole hardness (Asker C-45, 50, 55, 60) and on different surfaces (Rubber and Concrete). We conducted repeated-measures ANOVA on LI measures, and one-sample t-tests to compare VALR with a threshold value. Midsole hardness and surface type mainly affected VALR. Several combinations of midsole and surface reduced VALR below threshold: C-45 with both surfaces (R: 69.72±8.10 BW/s, C: 71.37±12.50 BW/s), and C-50 with a rubber surface (68.21±10.52 BW/s). Combining softer midsole and surface results in the greatest cushioning, which demonstrates the benefit of considering both factors in reducing running injuries
EFFECTS OF HALF-MARATHON RUNNING ON QUADRICEPS AND HAMSTRING TORQUE
Get PDFThis study aims to investigate changes in concentric and eccentric quadriceps and hamstring torque following half-marathon running on the treadmill. Thirty-eight recreational runners participated in this study. Isokinetic dynamometry measured torque before, 5 minutes, 24 and 48 hours after completing half-marathon. A significant decrease in concentric and eccentric torque were observed at 5 minutes after a half-marathon for both hamstrings (all p \u3c 0.001) and quadriceps (all p \u3c 0.001), with recovery evident within 24 hours. However, 48 hours after the half-marathon, individuals exhibited increased concentric hamstrings torque (p=0.034) and eccentric quadriceps (p=0.002) compared to the baseline. Running a half-marathon may increase the risk of running injuries. However, these effect were transient, with torque levels returning to baseline within 24 hours
THE IMPACT OF GROUND REACTION FORCE VARIABLES ON BEND SPRINT RUNNING PERFORMANCE
Get PDFThis study aimed to investigate force production and highlight kinetic variables that relate to bend sprinting performance. Eight competitive sprinters undertook three 60 m sprints around a 36.5 m bend radius. Paired t-tests were run using statistical parametric mapping to compare the left and right stance phases. Pearson correlation coefficients were calculated to assess the relationships between step velocity (SV) and kinetic variables. Significantly greater vertical and inward force was produced during early right stance compared to left. Left inward force was significantly greater than left during mid and late stance. Only braking durations were significantly negatively correlated to SV. This research highlights the asymmetries in GRF production and that the additional demands of the bend may alter the typical relationships between kinetic variables and SV
MARKERLESS BIOMECHANICAL ANALYSIS OF FORMER ELITE RHYTHMIC GYMNASTS
Get PDFThis study addresses the critical gap in understanding the biomechanics of key rhythmic gymnastics elements with high loads on the feet and ankles, specifically Fouetté balance and turns. These elements require repeated plantar and dorsiflexion movements. The study analyzed the forces and ankle sagittal angles of four former elite gymnasts using markerless motion capture and force plates. We segmented each movement into distinct biomechanical phases, particularly in \u27Relevé\u27 and Plié positions. Higher forces were observed during the Fouetté turn, and higher plantarflexion angles were found during the Fouetté balance. To the authors best knowledge this is the first study to segment and quantify common movements in rhythmic gymnastics, offering potential benefits for enhancing rhythmic gymnastics specific training and rehabilitation programs
LOAD-VELOCITY BEHAVIOR DURING THE FIRST AND SECOND PULL OF THE SNATCH AND CLEAN
Get PDFThe purpose of the study was to examine the effect of barbell load on the velocity during the first and second pull of the snatch and clean. Fifteen elite weightlifters (M= 6, F = 9) performed multiple repetitions of the snatch and clean at 75%-100% of their one-repetition max. Load-velocity (L-V) regression models were created for the first pull and second pull for each of the two lifts. The slopes of the L-V relationships were extracted from each model to determine how load affects each pull of the corresponding lifts. The results suggested that the L-V slopes for the snatch (p = 0.006) and clean (p = 0.015) differed between the first and second pull. For the snatch, the L-V slopes were greater during the second pull, whereas the opposite was true for the clean. Interestingly, differences in L-V slopes during the snatch were less pronounced in weaker lifters
MAXIMAL INTERNAL KNEE ADDUCTION MOMENT IS NOT RELATED TO LATERAL CENTRAL FEMUR CARTILAGE STRUCTURE IN HEALTHY RUNNERS
Get PDFThe purpose of this study was to investigate the association between maximal internal knee adduction moment (KAM) during running and the lateral knee cartilage structure in healthy adults. 1104 participants 18-65 years old participated in this study. Biomechanics of the lower extremity during running at the individual’s self-preferred speed were recorded using motion capture system and force plates. A 1.5T MRI scan was used to determine T2 relaxation time of the lateral central femoral cartilage. When controlled for age, sex, running distance and morphological findings of a radiologist in a statistical model, the KAM (OR = 0.95, CI 0.80-1.12) did not significantly influence T2. The KAM did not appear to increase the odd of having a higher T2 relaxation time of the lateral central femoral cartilage indicating that this load may not be related to the deterioration of the collagen structure
OVERWEIGHT AND UNDERWEIGHT IMPLEMENTS’ IMPACT ON CRITICAL FACTORS OF ROTATIONAL SHOT-PUTTING TECHNIQUE
Get PDFThe purpose of this study was to evaluate the impacts of heavy and light implements on the kinematics of the rotational shot put technique. Ten collegiate shot putters completed three rotational shot put attempts using competition, overweight and underweight implements. Whole body kinematics were recorded on each throw to evaluate key aspects of shot putting technique including pelvis-torso separation, rear leg hip flexion, rear leg knee flexion, and peak pelvis angular velocity during specific phases of the throw. Results of this study highlight that when using an overweight implement, athletes have significantly less hip flexion compared to the competition-weighted implement (52.11° ± 15.47° vs. 31.98° ± 10.62°, p=.0097). No other critical factors of technique showed any significant changes between conditions. These findings support the strategic incorporation of heavy and light implements in rotational shot put training