Adaptive shortening, i.e., tightness that develops as a result of a muscle or muscle group remaining in a shortened position can occur rather quickly over the course of a baseball season. It is often caused by prolonged exposure to a particular posture, such as sitting on a bench and/or being in a bent over, “ready” fielding position for three or more hours at a time during the course of a long competitive season. With adaptive shortening, one muscle or muscle group becomes tight and hyperactive, while the opposing muscle or muscle group becomes loose and underactive. There is also an increased neural drive to the tight, hyperactive muscle group and reduced neural drive to the functional antagonist. In baseball, adaptive shortening is often observed in the muscles that flex the hip (psoas), extend the knee (quads) and abduct the thigh (tensor fascia lata and IT band), and can lead to pain in the low back, hamstrings and/or lateral knee.
The key to preventing and eliminating adaptive shortening is to stretch the tight, hyperactive muscles and strengthen the weaker, underactive muscles. While this problem can be addressed indoors by the trainer and strength coach, a committed player can control the situation by performing three, simple, daily stretches on his own. Each stretch is performed from a half-keeling position so there is no getting up and down or frequent changes of position which makes them easy to perform in almost any environment.
1. Half-kneeling hip flexor or psoas stretch. Stretching the psoas will increase hip flexion, which in turn, will increase the neural drive to the hip extensors (glutes) and reduce dependence on the hamstrings to extend the hip. To perform this stretch, place the knee of the hip you want to stretch on the ground and opposite foot flat on the ground. Extend your trunk upright with both arms straight up in the air and over the head. Set the core to keep the low back flat, tighten the glutes on the down side leg and shift your weight forward onto the front foot, keeping your trunk, shoulders, arms and head upright until you feel the stretch in your hip flexors. Don’t arch your back or lean forward. Hold for 10 seconds, repeat 2-3 times, relax and change legs.
2. Half-kneeling quad stretch. Assume the same starting position as the previous stretch (psoas stretch) but this time plantar flex the ankle and turn the toes of the down side leg under your foot. Extend your trunk upright with both arms extended straight up. Set the core, tighten the down side glutes and shift your hips forward until you feel the stretch in your quads. Don’t arch your back or lean back.
3. Half-kneeling TFL and ITB stretch. Assume the same starting position used in the psoas and quad stretch, but this time planter flex the ankle and turn your foot inward so that the weight is on the lateral side of your ankle. Extend your trunk upright with both arms extended straight up. Set the core, tighten the down side glutes, shift your hips forward and lean your trunk laterally away from the down side knee until you feel the stretch in your TFL and ITB. Don’t arch your back or lean forward. Hold for 10 seconds, repeat 2-3 times, relax and change legs.
Although adaptive shortening can occur rather quickly and can have serious effects on your health and performance, it is relatively easy to prevent and correct. These stretches outlined are effective, relatively easy to do and can be performed on your own, in the weight room, dugout or on the playing field.