Rowing is a low impact sport with movement only in defined ranges, so twist and sprain injuries are rare. However, the repetitive rowing action can put strain on knee joints, the spine and the tendons of the forearm, and inflammation of these are the most common rowing injuries. If one rows with poor technique, especially rowing with a curved rather than straight back, other injuries may surface, including back pains. Blisters occur for almost all rowers, especially in the beginning of one's rowing career, as every stroke puts pressure on the hands, though rowing frequently tends to harden hands and generate protective calluses. Holding the oars too tightly or making adjustments to technique may cause recurring or new blisters, as it is common to feather the blade (previously described). Another common injury is getting "track bites", thin cuts on the back of one's calf or thigh caused by contact with the seat tracks at either end of the stroke.
The table on the left gives the speed of waves of different wave lengths in deep water. “Deep” in this context is not an absolute value, but is relative to wave length. The simple relationship starts to to breakdown when the depth of the water is less than 1/4 th the wave length. At that depth the bottom exerts sufficient drag on the wave to slow its motion and thus decrease the wavelength [equations and more about wave speed].
Function plays a large role in defining good design. When designers look at an object, they don't just consider its aesthetic appearance; they should also challenge it to be more versatile, to respond to the user's need, or to achieve its purpose more elegantly. Good design has the capacity to solve problems that sometimes we didn't even know we had. This is one of the ways design touches and enriches our everyday life.
Do you need a machine that folds up? If you've decided to avoid a water rower for space reasons, you may prefer a model that folds up for storage. Even better, some rowing machines have wheels fitted to them, so that once it's folded up, you can steer it to a storage space out of the way. You can find a foldable design in many magnetic and some air rowers.
Decreasing speed of waves as water becomes shallow has dramatic consequences on the beach. As the waves slow, their profile (Figure on right) is laterally compressed and since each wave must carry the same energy it becomes higher. As the wave approaches shore this process continues until the height exceeds 1/7 th the wave length and the wave becomes unstable. Then the wave breaks.