Анатомия бега (2010,иностр
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Running Focus
Balancing the abdominal muscles is the goal of this exercise. Most abdominal exercises focus on the large muscle of the abdominals, the rectus abdominis. The side-to-side movement of this exercise helps develop the external oblique, also strengthened in the hanging leg raise with twist. The strengthening of the external oblique helps minimize the side-to-side listing at the end of a fast race or hard effort in a speed workout. Because the smaller muscles of a large muscle group—that is, the abdominals—fatigue easier than the large rectus abdominis, it is important to do exercises that specifically target the smaller muscles so that they maintain their relative strength and do not become dominated by the larger muscle.
The practical application of this exercise is to eliminate the side-to-side rocking of the upper body during the gait cycle. While a leg length discrepancy could cause this rocking, the usual culprit is poor abdominal strength, especially weak oblique muscles. The inability of the abdominal muscles to maintain erect posture causes an awkward side-to-side motion generated by a pelvis that is not aligned.
ABDOMINALS AND PELVIS
Single-Leg V-Up
Execution
1.Lie flat on the back with your hands reaching back behind your head. One leg is steepled and the other is raised approximately six inches off of the ground.
2.Leading with the chin and chest, engage the abdominals, raising up as in a sit-up, but also raise the leg that is off the ground, meeting the hand at its apex.
3.Recline to the initial position.
Muscles Involved
Primary: rectus abdominis, transversus abdominis, iliopsoas Secondary: hamstrings, gluteus maximus
Running Focus
This exercise is dynamic and quickly fatigues the abdominal muscles and the iliopsoas. Because of the incorporation of both the upper body and lower body, there is more of a whole-body movement that more closely resembles a running movement than some of the other exercises in this chapter. Performed to failure, this exercise and its variation with a medicine ball can be an entire abdominal workout, especially if done as the final exercise in a strength-training session.
VARIATION
Single-Leg V-Up With Medicine Ball
The use of the medicine ball works the abdominals harder because of the added weight. Since the medicine ball is held away from the abdominals, even a five-pound ball feels heavy as a result of its distance from the fulcrum (the abdominal muscles). Also, the coordination of the movement with the added weight helps develop coordination, a skill not gained when just running in a forward motion.
CHAPTER 8
UPPER LEGS
There is no real division between the core and the upper leg; all the limbs merge seamlessly into each other. Some of the pelvic muscles help movement and stability of the leg, and vice versa. The same occurs at the knee, where muscles are described as crossing over two joints, so they influence the action and steadiness of the joints. The upper leg (figure 8.1), or femur, is inserted via the hip joint into the pubis and ischium. The other bone of the upper leg, the patella (knee joint), is really a pulley. It runs in a groove at the lower end of the femur to help guide the extending forces of the quadriceps muscles around the knee.
Figure 8.1 Bony structures of the upper leg.
The primary function of the quadriceps group (figure 8.2a) is to extend the knee. From the outside to the center line, the vastus lateralis, rectus femoris, vastus intermedius, and vastus medialis combine at the superior pole of the patella and straighten the knee joint with a pull through the patellar tendon on the upper part of the tibia. Contraction of this, the largest muscle group in the body, also pulls the knee toward the chest. It is particularly relevant to the sprinter, who gains extra stride length with big quadriceps contractions; however, this high knee lift wastes energy in a long-distance run, so the hip and knee have much smaller ranges of motion when covering longer distances. The role of the quadriceps in the running action is therefore twofold, though the intent of both movements is to increase the stride length (see figure 3.2 on page 23). If at the same time the knee is fully extended and the quadriceps muscles exert the maximum flexion to the hip, not only is the stride length maximized, but the added time in the air will also allow the momentum already generated to propel the body farther forward.
Much the same goes for the hamstring muscles (figure 8.2b), which also span the two joints but act in an opposite manner to both extend the hip and flex the knee. The semimembranosus, semitendinosus, and biceps femoris have some congruity in the center of their bulk, having
arisen from different points within the pelvis, but then separate behind the knee and are inserted into the rear of the tibia and fibula. Contraction of the hamstrings drives both the upper and lower leg backward, a movement that tends to be exaggerated in a sprinter (see figures 3.3 and 3.4 on pages 24 and 25). Increased knee flexion would be inefficient to a distance runner; a greater percentage of the hamstring motion for a distance runner occurs at the hip.
It may be helpful to consider each full hamstrings group as two separate half muscles. This may sound paradoxical, but although it is the upper portion that links over the hip joint as an extensor muscle, the lower portion both flexes and limits extension of the knee. There is, of course, no actual physical distinction within the muscle groups when they are microscopically examined; the difference is purely functional. In the distance runner the hamstrings have a limited range of motion over both the hip and knee joint, although their contraction is very powerful over these small angles.
Figure 8.2 Upper leg: (a) front and (b) back.
It may seem strange that the knee needs to be able to twist, but how else would a runner turn corners or cope with uneven terrain? The knee (figure 8.3) has two collateral ligaments on the inside and outside that allow it to hinge to and fro, but rotation depends on the half-moon-shaped menisci, also known as cartilages, which are placed between femur and tibia and spread weight through the knee joint. They also allow the bones to twist on each other. An anterior and posterior cruciate ligament within each knee, placed in a crosslike shape, obstruct excessive forward and backward movement of femur and tibia on each other. It should be stressed, however, that these ligaments are there to guide knee movement and play only a small part in maintenance of knee stability, which depends mostly on the strength of the muscles.
The thigh muscles need both strength and flexibility, each of which can be improved by exercise. The maintenance of a balance between the two is also vitally important because being muscle-bound will do little for pliability; the converse is equally true in that lack of muscle bulk will cause relative weakness.
Figure 8.3 Knee ligaments and tissue.
Specific Training Guidelines
Protection of the knee joint while performing some of the following upper leg exercises is an important consideration. Because both the quadriceps and hamstrings groups of muscles attach to the knee, and the knee joint twists to adapt to terrain variations, turns, uphills, and downhills, there is constant stabilization and relaxation of the joint. The lunge exercises are difficult to perform initially, so care must be taken to perfect the motion with lighter weight before increasing the resistance. A machine-aided exercise helps protect the joint, but it has a fixed range of motion that does not make it the best functional exercise.
The exercises listed for the upper legs are good introductory and strength (threshold) phase exercises. However, they should not be done during the final phase of training, which emphasizes V
O2 max. During the final phase, substitute the plyometric exercises listed in
chapter 12 to meet a runner’s needs without overly fatiguing the muscles.
ADDUCTOR FOCUS
Hip Adductor Machine
Execution
1.Sit in a proper seat position, with machine pads on the insides of the knees.
2.Squeeze inward on the pads. The motion should be fluid but with consistent effort throughout.
3.Return to the original position by gradually resisting the weight.