Analysis Of Biomechanical Characteristics Of Rock Climbers' Jumping Technique

Research objective: Due to the lack of biomechanics research in rock climbing,and the importance of jumping technology in rock climbing.In order to analyze the biomechanical characteristics of jumping,to discuss the problems existing in the training of athletes,to provide theoretical guidance for the scientific training of athletes,to prevent the injury of athletes,to improve the teaching method and improve the teaching effect.Research methods: Through literature reading and collating,a reasonable experimental design was carried out.46 suitable subjects were included,including 24 males and 22 females.The surface electromyography test system and isokinetic muscle force test system were used to conduct experiments,and root-mean-square amplitude,integrated electromyography value and relative peak moment were collected.The characteristics of muscle activation,muscle contribution,muscle strength,stability and balance were analyzed.Research results:1.During jumping,the activation degree of hand muscles is higher than other muscles;In all stages,the degree of activation of the hand and core in oblique wall was significantly higher than that in straight wall,and the degree of activation of the lower limb muscles in straight wall was higher than that in oblique wall.The activation of lower limb muscles was highest in the air stage and lowest in the grip stage.In terms of trunk muscles,the flexor(rectus abdominis and pectoralis major)had the highest air stage,the grip stage was higher than the preswing stage and the take-off stage,and the extensor(erector spinus and latissimus dorsi)grip stage was lower than the take-off stage.In the upper limb muscles,the air phase is the most active.2.Ranking of muscle activity contribution in each movement stage: take-off stage,grip stage,pre-swing stage and aerial stage.Except for female athletes’ aerial stage and aerial stage,the ranking of other stages is the same;The activity contribution of all lower limb muscles was higher in take-off stage than in other stages,but lower in pre-swing stage and grip stage.The highest contribution degree of trunk flexor activity was in the grip stage,while the highest contribution degree of extensor activity was in the jumping stage.Most of the upper limb muscle activity contributed the highest during the take-off phase.3.Shoulder joint has the best muscle strength at 120°/s and 180°/s;The elbow joint showed the best muscle strength at 60°/s;The hip flexors of male athletes were the highest at 120°/s,the extensors at 60°/s,and the hip joints of female athletes were the best at 180°/s.The relative peak moment of flexor and extensor increased with increasing speed,while the peak moment of extensor decreased with increasing speed.Ankle joint muscle strength is best at 120°/s and 180°/s.4.Shoulder joint stability is poor,the relative peak moment of flexor muscle is 50%of extensor muscle;Elbow joint stability is the best,the flexor extensor ratio is close to 100%;Hip joint and knee joint had good stability,ranging from 67% to 78%;Ankle joint stability is poor,flexor extensor ratio is close to 50%.5.Shoulder joint balance is better,the lateral flexor muscle of the same name reaches81-85%,the extensor muscle reaches 90%;The elbow joint balance is better,the flexor muscle reaches 88%-89%,the extensor muscle is stable at 85%;Hip joint is the most balanced joint,the lateral flexor extensor muscle with the same name reached more than 95%;The balance of knee joint is better,reaching 92-98%;The ankle joint was kept above 90 percent.Conclusions: 1.The angle of the rock wall was a key factor affecting the degree of muscle activation and muscle contribution of the athletes.2.forearm muscles had the highest activation;each muscle had the highest activation during the takeoff phase;trunk flexor activation was significantly higher during the grip phase.3.Except for the trunk flexors,which had the highest contribution in the grip phase,the rest of the muscles had the highest contribution in the jump phase;the flexors of each joint contributed more than the extensors in the inclined wall jumping action.4.rock climbers have good muscle strength;elbow flexors have good performance in slow state and extensors in fast state;hip flexors and knee flexors are poor;ankle plantarflexors have good performance in fast state and dorsiflexors in slow state.5.climbers have poor stability of shoulder joint;elbow joint has the best stability,the faster the speed the worse the stability;hamstrings are well developed,knee joint is the most stable in the medium and fast state;climbers have excellent heterolateral joint balance.