Balanced Body for Reduced Injury Risk
This is taken from a presentation that I recently did for the Winter Park Competition Center as their Team Physical Therapist. While I enjoy working with our young, athletic and motivated skiers, I do treat patients of all ages and abilities, from all walks of life and with widely varied interests.
When the subject of injury prevention comes up, I recall a sage reminder that we cannot truly prevent injuries, but we can reduce the risk of incurring them. Injury prevention, or risk-reduction can be categorized as either external or internal. External factors would include things such as fencing, padding around lift towers, safety gear such as properly set releasable bindings, helmets, spine protectors and air bags. We can also look at less controllable external factors such as the environment - weather and snow conditions. Periods of low snow, for example, when the available snow gets packed into a hard and icy sheet, are accompanied by a rise in the rate of injuries. Powder days on the other hand, result in fewer injuries. Those injuries that do happen when powder fever is rampant, however, often involve rotational injuries such as those that occur during a twisting fall.
Internal risk factors are inherent within the skier. Strength, conditioning, flexibility, and motor control - the latter of which encompasses coordination, agility and balance - are all things that a skier possesses and that can be enhanced with training. A useful concept when we consider what constitutes healthy objectives for athletic pursuits, or even everyday life, is one of balance. Not just the balance that keeps one from falling over, after all, skiing is very much a balance sport, but I am referring to the balance of forces within the body. Balanced forces can mean appropriate strength ratios of muscles in opposing muscle groups, such as hamstrings and quadriceps on either side of the thigh.
Balance within can also mean healthy ratios between adjacent muscle groups along the kinetic chain. The kinetic chain is the linkage of one body part to another through the series of joints connecting one body part to another. These joints can be thought of as links in a chain, progressing from the center outward to the extremities to connect our center with the environment around us through our hands and feet.
A common and very important balance of forces to consider is that of the core, or low back area relative to the legs. We skiers use our legs very intensely, feeling the quad burn that accompanies a fervent desire to get as much time on snow as we can. We even work to develop more quad strength so that we won’t feel that thigh-sizzle so early and have to quit before our snow-sliding appetites have been sated. As our quads and hips get stronger through all of the contortions and gyrations we go through to slide down mountains in control or to slip-slide along on snowy paths, they also tend to get stiffer, especially if we don’t finish each ski day with a good stretch. Strength with length is the ideal, but how many of us give as much attention to stretching as we do strengthening, and especially the strengthening of just plain participating in our sport?
This lower body strength and stiffness becomes important when we consider the design of the skeleton. The spine can be thought of as a series of blocks, vertebrae stacked one upon another, to create a flexible center of movement as well as a protector for our control center, the central nervous system. The ribcage that protects our heart and lungs attaches to the thoracic spine, reducing the degree of motion of that region due to its inherently stiff structure. We can move the thoracic spine, but it does not move as easily as the lumbar spine, or low back beneath it. The spine sits on the pelvic ring - three large blocky bones that are connected by three joints that permit very little movement. So we have a bony, nearly immovable pelvic girdle, a stiff thoracic region and sandwiched in between we have the lumbar spine, five vertebrae that are a skeletal achilles heel, a relative weak link in the chain. This relationship is why core strength is so important. That vulnerable low back needs protection from the muscles that support it.
Because the pelvic girdle is the base upon which the spine sits, pelvic positioning affects spinal control and stability. If the forces below the pelvis are stronger than the forces above the pelvis, pelvic motion, and thus spinal position and stability will be dictated by what the legs are doing. A great example of this is found when we consider the sitting position you are most likely in right now. Short, tight hamstrings come off the bottom of the pelvis and will tend to pull the pelvis so that the top tilts back. A posterior pelvic tilt means that the low back has to roll back into a more rounded position, which is one of the things that can lead to disc problems, due to over-stretching of the vertebral discs in back. Strong spinal muscles above the pelvis would be needed to counteract the pull of the hamstrings below, and restore a balanced set of forces above and below the pelvis.
Skiers, or for that matter, any mountain sport athletes, who have a lot of strength in their legs would be best served by strengthening up the muscles above the pelvis, aka, the ‘core’, to match the strength that they have in their legs below. Staying consistent with flexibility in the legs and hips will also help to balance the forces that battle for control of the pelvic orientation and thus reduce the risk of injury to the spine above.
I will provide more injury prevention tidbits in Blog posts to come, but for now, I will leave you with these nuggets of food for thought to chew on… until next time,
Jeff Russell MS PT
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