美国伊利诺斯州的发明家本浬特,在十多年前,偶然发现,如果把各种带柄工具的柄做成弯形,使用起来更省力气。因使用直柄工具时,手腕就得向下弯,使靠近腕部的神经组织与腱组织很紧张,易于疲劳(见图)。经过摸索,他确定,弯曲十九度最为合适。这样,手握工具时,工具柄的弯曲与穿过掌心的生命线[注]的弯曲同是十九度,恰好吻合。他提出一个简单而深刻的问题:为什么让手去适应工具而不改变工具的形状来适应手呢?他的这一发现很快就获得了专利。但是,人们千百年来一直使用直柄工具,改变这种习惯很难。最先试用本浬特的弯柄器具的人都曾经吃过直柄的苦头:有一个网球运 In Ben 10, the inventor of the state of Illinois in the United States, more than a decade ago, it was discovered that if the shanks of various shank tools are curved, they are less laborious to use. Because of the use of straight shank tools, the wrist has to bend down so that the nerve tissue near the wrist and tendon tissue is very tight and easy to fatigue (see photo). After exploration, he determined that the most appropriate bending nineteen degrees. In this way, when holding the tool, the handle is bent exactly the same as the curve of the lifeline [Note] passing through the palm of your hand, nineteen degrees. He raises the simple, yet profound question: Why should the hand adapt to the tool without changing the shape of the tool? His discovery was quickly patented. However, it has been difficult for people to use straight-handle tools for thousands of years. The first trial of this special curved handle handle people who have ever suffered a straight handle: There is a tennis player