Kinesiology of Exercise


The squat is a very beneficial exercise, but it does not develop the legs and hips to as great an extent as is possible. To get a greater ROM in the hip joint due to the greater stretch and contraction of the hip joint extensors, while at the same time creating a greater stretch of the hip flexors, you should do the lunge. This exercise is quite effective and safe for the knee joint when done properly. Its greatest value, however, lies in stretching and strengthening the hip joint muscles. 

In order to get these benefits is important that you do what can be called a classic lunge in which a long stride (4-6 feet) is taken. You do not get these benefits if you do what many people call a lunge but which in reality, is closer to what can be called a split squat. 

In a split squat you take a short stride so that your feet are no more than 3-5 feet apart. The lowering and raising of the body appears more as a squat exercise rather than a true lunging action. Because of this you must be sure that you do a lunge and not a split squat to get the many benefits, especially for athletes

Major Muscles and Actions Involved

In the lunge, extension occurs in the hip and knee joints. In this action the thigh moves away from the shin and pelvis as the leg is straightened. In addition, the erector spinae muscles contract isometrically to stabilize the spine.

Sports Uses

With some minor exceptions, it can be said that the lunge is valuable in all the sports mentioned in the section on the squat exercise. However, the lunge also provides other benefits, such as development of hip joint flexibility, which is very important in sprint running. In the push-off, the greater the flexibility of the hip joint flexors, the longer is the stride that can be attained.

Exercise Analysis

  • In order to get the full benefits of this exercise in the hip joint area, it is essential that you keep your trunk erect and not lean forward. With your trunk in this position, there is maximum flexion in the hip joint of the forward leg in the down position. 
  • This, in turn, brings on a strong stretch of the gluteus maximus muscle for a stronger contraction. In essence, the deeper the lunge, the greater the involvement of the gluteus maximus and hamstrings. You will also develop greater hip joint flexibility. 
  • Most athletes feel a tremendous stretch on the hip flexors of the rear leg in the initial stages of this exercise, but only when the lunge is done as described. By doing the exercise slowly and gradually over a period of time, you will develop the necessary flexibility to do the exercise for maximum effectiveness. 
  • With the barbell held across the back of your shoulders (as in the back squat) there is a greater tendency to lean your trunk forward. This may decrease the ROM and the gluteus maximus muscle action. In addition, the spine can be injured if it is allowed to flex in the bottom position when you have heavy weights on your shoulders. 
  • Leaning forward with the trunk and taking too short a stride are the most common errors when doing the lunge. This is usually the result of poor hip joint flexibility and a weak lower back. Leaning forward with the trunk is potentially injurious to the spine. 
  • In addition, it places excessive pressure on the forward knee, which can also be damaging.
    Also important is that you do not get a strong stretch of the hip flexors. These errors lead to poor performance in the lunge as well as on the field or court and even when doing plyometric exercises such as split squat jumps.
  • When you strongly contract the erector spinae in order to hold your trunk erect, your pelvis is held in place (normal position) along with your trunk. Because of this, the lunge helps to develop the stabilizing actions of the erector spinae muscles. 
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