Abstract
BACKGROUND:The driving strength may be an undiscovered power source with a great developing potential. To clarify the relationship between driving strength and lower limb strength is of great importance to the development of the theory of human movement science.

OBJECTIVE: To find out the relationship between the maximal driving strength and the maximal lower limb strength.

DESIGN: Observation and contrast analysis.

SETTING: Department of Physical Education, Ocean University of China.

PARTICIPANTS: A total of 94 male healthy university student athletes were enrolled from Ocean University of China between December 2000 and November 2001, aged (19.7±1.7) years and weighed (75.27±2.93) kg. All the objects that had never used the hip stress strength training apparatus took part in the experiment voluntarily.

METHODS: Forty-six of 94 subjects were randomly selected to take part in an 11-month program of driving strength improvement by using hip stress lower limb strength training apparatus (far fixed hip-stressed lower-limb strength training apparatus and near fixed hip-stressed lower-limb strength training apparatus were manufactured by Ocean University of China, pattern number: HNLPT-04Ed, HNLPT-04E respectively). And other 48 subjects were arranged as the control group using current strength training methods (resistance forward leg extending and barbell squatting). For experimental group to do strength practice and measurement, the object sat on the hip-supporting seat straightly, pressed his hip against the hip-stressed resistant unit and put his feet on the pedals, then extended leg at the preset angle and locus. When the near fixed device was used, the trainee kept his hip and body trunk in a static position, and drove the pedals backward. When the far fixed device was used, the pedals fixed in a static position, the hip and trunk were pushed foreword by legs.①Multifunction strength training apparatus and far fixed hip stress lower limb strength training apparatus were respectively used to test the maximal lower limb strength and maximal driving strength of 94 objects.②Comparisons between before and after training in two groups were made in the maximal driving strength and the maximal low limb strength.

MAIN OUTCOME MEASURES: The maximal leg strength and leg driving strength of 94 healthy subjects before and after training.

RESULTS: All the 46 subjects in experiment group and the 48 subjects in control group were involved in the result analysis.①The maximal driving strength was lower than the maximal leg strength [(1 135.53±196.98) N, (2 414.62±424.05) N, P < 0.01].②After the 11-month special training with hip stress lower limb strength training apparatus, the maximal driving strength of experiment group got a significant increase [(1 124.94±206.19), (1 762.24±193.45) N, P < 0.01]. No significant differences were found in the control group.

CONCLUSION: The increase of driving strength from the hip stress lower limb strength training may be an increase of athletic capability that can never be achieved by any current strength training method and apparatus. The application of this method will make it possible to realize great breakthrough of world sports records in the events of running and jumping.

INTRODUCTION

The slogan of famous Olympic Game is "higher, faster and stronger," which displays the lofty spirit of Olympic and the urgent need of human to break through athletic limit and create new miracle of sports results. For many years, thousands of sport scientists and coaches have strived hard for it and acquired a lot of outstanding achievement on developing athletic limit, which lead to many break through of sports record in speed and power events.
With the development of science and technology, and the improvement of training method, the world records of sport get nearer to its theoretical limit. The research for athletic limit promotion becomes more and more difficult.
Within the relevant sport qualities of athletic limit capacity in running and jumping, strength has always been the most important one.
While the driving strength that is indispensable in every event of running and jumping is the even-essential element of special athletic limit capability[1-9]. For many years, researchers have successfully improved the maximal lower limb strength by using various kinds of training methods. However, how to improve the maximal lower limb strength in the action of driving and take-off in the running, long jump and triple jump remain unclear to date[6,10-11]. Because the maximal driving strength of human body can't currently be accurately tested or evaluated, none of report has bee seen about the relationship between maximal lower limb strength and maximal driving strength.
The great load resistant driving has not been realized by now. The intensity of training method for improving driving strength is relatively smaller than that of traditional method for lower limb strength training[2-4,12,13]. Based on this situation, we are reasonable to infer that the current driving strength of human is relatively lower and weaker than its general lower limb strength. The driving strength may be an undiscovered power source with a great developing potential.
To clarify the relationship between maximal driving strength and maximal lower limb strength has great importance to the development of the theory of human movement science. It will lead to new breakthrough of athletic limit and world record of running and jumping if the current driving capability can be obviously improved.
Based on above consideration, author decides to conduct applicable research on maximal driving strength evaluation and promotion.

SUBJECTS AND METHODS

Subjects
A total of 94 male healthy university student athletes were recruited from the Ocean University of China between December 2000 and November 2001, aged (19.7±1.7) years and weighed (75.27±2.93) kg.
All the objects that had never used hip-stressed strength training apparatus took part in the experiment voluntarily.

Methods
Theoretical designing and mechanical designing
The working structure and working direction of strength trainee is highly related to the stress point of the trainee. In seating posture of leg extending forward, sacrum is resistance stress points. In barbell squatting, shoulders are stress points and legs extend downward. To realize heavy load leg driving, the stress point must be at the front part of the human body. Hip is the gravity center of human body and it should be the best stress point beside the feet for realizing heavy load leg driving.
According to the thought of inference and theoretical designing, author created the hip stress lower limb strength training apparatus with it key structure-hip stress resistance unit. There are two kinds of hip stress lower limb strength training apparatus, far fixed hip-stressed lower-limb strength training apparatus and near fixed hip-stressed lower-limb strength training apparatus (manufactured by Ocean University of China, pattern number: HNLPT-04Ed, HNLPT-04E) (Figure 1). Hip-stressed lower-limb specific strength training and measuring apparatus is composed of the following parts: frame, slide-way, rope, pulley, load-block, pedal, and hip stress resistance unit (Figure 2).

Driving strengthen improvement
Multifunction strength training apparatus and far fixed hip stress lower limb strength training apparatus were used to separately test the maximal lower limb strength and maximal driving strength of 94 objects that had never used hip stress lower limb strength training apparatus before. And 46 of them were randomly selected to take an 11-month program of driving strength improvement by use of hip stress lower limb strength training apparatus and other 48 as control group using current strength training methods (resistance forward leg extending and barbell squatting).

For experimental group to do strength practice and measurement, the objects sat on the hip-supporting seat straightly, pressed his hip against the hip-stressed resistant unit and put his feet on the pedals, then extended leg at the preset angle and locus. When near fixed device was used, the trainee kept his hip and body trunk in a static position, and drove the pedals backward. When training with far fixed devices, the pedals fixed in a static position, the hip and trunk were pushed foreword by legs (Figure 3). All the subjects of two groups were compared in maximal driving strength and maximal low limb strength before and after training.

The technical index and training function realized by hip stress lower limb strength training apparatus
Working direction: ①Horizontal forward leg extending;②Backward driving and extending.
Maximal working load:① Near fixed apparatus: 2 940 N (single leg);② Far fixed apparatus: 3 920 N (double legs).
Maximal working range:①Horizontal distance of extending and driving: 2.2 m (near fixed apparatus);②Horizontal distance of extending and driving: 1.6 m (far fixed apparatus).
Start working angle of knee: 20°－160°
Adjustable vertical distance from hip to ground: 0.3-1.2 m
Working speed: 0.001-2.500 m/s
Suitable body height of trainee: 130-200 cm
All the technical index and training function revealed that hip stress lower limb strength training apparatus could realized the special training of driving strength at the utmost loading.

RESULTS

Quantitative analysis of participants
All the 46 subjects of experiment group and the 48 subjects of control group were involved in the result analysis.

Basic physical index of participants
There was no significantly statistical difference between control group and experiment group in basic physical index (P > 0.05).

Comparison of maximal lower limb strength and maximal driving strength of all objects
The maximal lower limb strength was significantly higher than maximal driving strength in all subjects [(1 135.53±196.98), (2 414.62±424.05) N, P < 0.01]. Such a small driving strength was probably the right factor to restrict people to break the world record of running and jumping at present. The results demonstrated the deduction we made before and indicated that the strength training methods and apparatus used currently had great defects on improvement of driving strength. In terms of developing this key athletic strength and effectively improving utmost potential, strength training methods and apparatus in use at present must be improved greatly and immediately.
Training effects of different strength training methods on improving maximal lower limb strength and maximal driving strength of the objects in two groups (Table 2)

After the 11-month training, both experiment group and control group got obvious increase on maximal lower limb strength, but only experiment group got obvious increase on maximal driving strength (P < 0.05).
The result of this experiment demonstrates two points: ①Through reasonable and scientific training, the maximal driving strength can be greatly improved. ②Among current strength training methods, only hip stress strength training method can effectively develop the maximal driving strength. The reason is that the working pattern, working direction, angle, locus, range and muscle mobilizing proportion of hip stress strength training method are just the same as the driving action in the real spots events of running and jumping. So the hip stress strength training method can develop the maximal driving strength to its utmost.

DISCUSSION

The significance of obvious improvement of driving strength in human
The leg driving strength is power source of all the sports event of running and jumping, because only driving strength can provide human body with forward power that running and jumping need to move forward.
The direction of driving action is backward, but the reaction force it gets from ground is forward. The greater driving strength exerts on the ground, the greater forward reaction force it gets, so the swifter human body moves forward and the farther people jump forward[14-18].
Just as the unexpected low level of driving strength of human at present, such a great increase of driving strength get from hip stress strength training method is also unexpected. The most important is not how much the driving strength increases, but on what level it increases to. In fact this kind of increase is the increase above the current utmost ability of human body and never be achieved from any training method at present[3,4,6-9,12,13]. It is a new breakthrough of utmost athletic potential of human. In the days the sports record gets nearer and nearer to the limit of human body, this breakthrough of human potential has much more important meanings.
Here we will not discuss precisely how much the sports record will be increase by the increase of driving strength. But one thing we can confirm that by using hip stress strength training method on the world top athletes, several world sports records will be broken in one or two years.

Conclusion
Driving strength, the important factor of utmost athletic capability of running and jumping events, cannot be accurately determined and effectively cultivated under current training condition and training method, additionally, it can not be evaluated precisely.
The key factor to realize heavy load training of driving strength is the stress point of training method and training apparatus. Only the stress point is to be fixed at hip, can we realize the evaluation and heavy load training of driving strength. The hip stress lower limb strength training method and apparatus created in this study realize this goal successfully.
Through the training with hip stress lower limb strength training method, the driving strength of human can increase obviously. This increase is a new increase that can't be realized by current training method and condition. It means the development of utmost athletic ability of running and jumping. It will lead to the breakthrough of world sports record by use of this training method reasonability and scientifically.

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髋受力下肢力量训练器对人体跑跳极限运动能力最大后蹬力提高的作用★

洪 涛
中国海洋大学体育系，山东省青岛市 266003
洪 涛★，男，1956年生，山东省青岛市人，满族，教授，硕士导师， 1989年成都体育学院毕业，硕士，主要从事运动生理、运动训练和人体运动工程的研究。
摘要
背景：人类后蹬力量可能是一种未能有效开发并具有极大开发潜力的动力源,阐明后蹬力量与下肢力量的关系对人体运动科学理论的发展具有重要意义。
目的：观察髋受力下肢力量训练器与最大后蹬力量、最大下肢力量提高的关系。
设计：观察对比分析。
单位：中国海洋大学体育系。
对象：实验于2000－12/2001－11年在中国海洋大学完成，选择94名从未用过髋受力训练器的健康男大学生运动员，平均（19.7±1.7）岁，体质量（75.27±2.93）kg, 所有被试对象均对受试项目知情同意。
方法：随机抽取其中46名受试者为实验组，采用髋受力下肢力量训练器（远固定髋受力下肢力量训练器型号：HNLPT-04Ed；近固定髋受力下肢力量训练器型号：HFLPT-04E，研制单位为中国海洋大学）进行历时11个月的后蹬力量提高训练。其余48名作为对照组采用现有的力量训练方法,即抗阻前蹬和负重蹲起。实验组受试者进行力量练习和测试时，坐于顶髋坐椅上，身体正直。脚踩踏板，按预定角度和轨迹作蹬伸运动。采用近固定机时，练习者的躯干和髋部固定不动，腿蹬踏板向后运动。采用远固机时，踏板和脚不动，髋部和躯干靠腿的蹬伸向前运动。① 采用多功能力量训练器和远固定髋受力下肢力量训练器分别测定94名从未用过髋受力训练器的受试者的最大下肢力量和最大后蹬力量。② 对两组受试对象于训练前后最大下肢力量和最大后蹬力量进行测量比较。
主要观察指标：① 94名从未用过髋受力训练器的受试者最大下肢力量和最大后蹬力量。②实验组及对照组受试对象于训练前后最大下肢力量和最大后蹬力量进行测量比较。
结果：纳入实验组46名及对照组48名受试对象均进入结果分析。①受试者平均后蹬力量为(1 135.53±196.98) N,小于最大下肢力量[(2 414.62±424.05)N，P < 0.01]。②经过11个月的髋受力下肢力量训练法的专项力量训练，实验组受试对象训练前后的最大后蹬力量高于实验前[(1 124.94±206.19)， 1 762.24±193.45] N，P < 0.01],对照组受试对象训练前后的最大后蹬力量差异无统计学意义。
结论：通过髋受力下肢力量训练使后蹬力量获得的提高是现有任何训练方法和训练器所无法获得的人体极限运动能力的提高，可使跑、跳世界纪录大幅度突破成为可能。
关键词：髋受力训练；后蹬力；下肢力；极限运动
中图分类号:R87 文献标识码:A 文章编号:1673-8225(2007)13-02586-03
洪涛.髋受力下肢力量训练器对人体跑跳极限运动能力最大后蹬力量提高的作用[J].中国组织工程研究与临床康复，2007，11(13):2586-2588,2592
[www.zglckf.com/zglckf/ejournal/upfiles/07-13/13k-2586(ps).pdf]
(Edited by Xiao DS/Yang Y/Wang L)