Last week we continued our discussion about the importance of single limb training and how frontal plane motion of the knee in the absence of excessive pronation and excessive pelvic motion may be more associated with weakness in the hip complex. This week, we will conclude this discussion on single limb training by looking at the hip.
Keeping in mind, the intent of this entire discussion is criterion based progression. The criteria for progressing single limb training from one level to another is the fact that the athlete is able to perform the previous level while demonstrating good technique and control at the foot/ankle, knee and hip. So specifically, what are we looking for at the hip?
As previously mentioned, sometimes due to our hyper focus on the knee, we forget about the hip/core and to closely asses what motion is occurring at the hip. Is it the pathological motion at the hip that is driving the frontal plane motion at the knee?
In single limb training, there are three predictable patterns that athletes fall into.
This is one of the most common and is easiest to identify by what happens on the contralateral side to the stance limb. In this case, the athlete is standing on his left leg and his gluteus medius on the left side and the core musculature on his right side (obliques, quadratus laborum, multifidus) is weak. The result is that the pelvis drops on the non-stance leg side. This will often lead to a significant shift of center of mass which leads to a loss of balance. This is easily observed by the athlete needing to touch the non-stance leg to the floor in order to maintain balance.
This is one of the most commonly missed compensations that occurs with a weakness in the core and pelvis. In this position, the gluteus medius is placed in a shortened position which has a significant impact on gluteus medius and core (obliques, quadratus laborum, multifidus) EMG activity. Try this! Stand up. Place your fingers lightly on your right gluteus medius. Stand on your right leg and put your left leg back in an athletic position. Feel the muscle contraction and fasciculations occurring in your right gluteus medius. Now, move over in the position represented in the accompanying picture. What happens to what you feel on your glut? You should feel a significant reduction in muscle contraction or almost completely inactive. By putting your gluteus medius and core in this shortened position, you significantly reduce the muscles' contractual ability.
This is really important to identify. If this is not identified, then the likelihood that this will be missed in single leg training is increased. If that is the case, then training that is being performed to improve gluteus medius and core strength will be much less effective and the athlete will be progressed to a level that they are not ready or capable of performing properly. This also means the athlete could potentially be progressed to return to sport with this residual weakness which will put them at risk of re-injury with return to sport.
This motion is a combination of both a trendelenburg and rotation at the hip. This represents more advanced weakness of the gluteus medius and core (obliques, quadratus laborum, multifidus). During this movement, the associated muscle weakness is significant enough that the muscles are failing through a larger range of the motion that they are biomechanically designed to resist.
These individuals are at a much higher risk for severe pathology at the hip (hip labral tears) as well as non-contact athletic low back injuries. In addition to the impact to additional injury potential, this motion also has a significant impact on athletic performance. The magnitude of kinetic energy loss and loss force production is most evident in the lose of vertical jump and sprint speed. These athletes will also have a much higher risk for loss of balance. In jumping sports (basketball and volleyball) this then puts them at greater risk for non-contact ankle injuries.
Two simple exercises that can drive improvement in the hip/core strength is the side plank and plank.
EMG studies of the side plank show significant EMG activity in both the gluteus medius in addition to the obliques and quadratus laborum. The side plank is performed incorrectly 80% of the time by athletes. Most of them demonstrate a retro trendelenburg during the movement, rotation of the hips or do not have their hips in line with their feet and shoulders. Ensuring proper technique with this exercise is critical to maximize the training effect.
EMG studies of the plank show significant EMG activity of the multifidus and rectus abdominus when performed correctly. Again, the plank is performed incorrectly 80% of the time by athletes. Most of them demonstrate a flexed hip position or increased spinal extension or rotation of the hips. Ensuring proper technique with this exercise is critical to maximize the training effect.
Next week we will start our discussion on fatigue state training. If you enjoy this blog, please share with your colleagues and follow us on instagram @ bjjpt_acl_guy and twitter at @acl_prevention. #ViPerformAMI #ACLPlayItSafe