[This is a guest blog by Erin Ritterbusch who is currently an intern at Athletic Lab. Erin is a recent graduate of Auburn University where she received her Master’s degree in Exercise Science with a concentration in biomechanics.]
If I could take one thing I learned during my Master’s program and run with it, it would be the importance of the Lumbopelvic Hip Complex (LPHC) (I basically had an entire summer class based around this concept). The level of strength and stability of the LPHC can make or break you in a sense. The LPHC plays a huge role in the body’s kinetic chain and connects the upper and lower halves of the body. The kinetic chain can be defined as the individual body segments, or links, are coordinated in their movements by muscle activity and body positions to generate, summate, and transfer force through these segments to the terminal link. (Kibler, 326). Essentially, this concept shows that forces produced by the lower body are transferred through the LPHC to the upper body.
The LPHC, also referred to as your core, is made up of the lumbar spine, pelvis, and hip musculoskeletal structures. This complex acts as a transition from your lower to upper body by serving to transmit forces that are generated. For this reason, it needs to be stable so that it doesn’t cause different parts of the body to overcompensate, which can result in injury. The core is considered the integral link in the kinetic chain. All sporting movements incorporate the transfer of energy from one segment to the next in the kinetic chain model. Despite the skill being performed, it is paramount that athletes have the correct postural control when performing movement skills. If an athlete lacks in postural control, then they cannot transfer the optimal energy to the distal segments and ultimately will be susceptible to injury because of compensations that are made in an attempt to make up for the lack of force production (Oliver, 3069).
It is important to maintain a stable pelvis for many reasons. If muscle imbalances exist the LPHC, this may result in altered force-couple relationships (the act of muscles or muscle groups moving together), which can lead to altered joint arthrokinematics (specific movement of joint surfaces), increased stresses to the LPHC, and potential injury. Muscles that may cause these issues are the gastrocnemius, soleus, adductor complex, hamstrings, hip flexors, abdominals, erector spinae, core stabilizers, latissimus dorsi, TFL/ IT band, gluteus medius, and gluteus maximus. Due to reciprocal inhibition, the ability to contract and relax muscles on opposing sides of a joint (synchrony of the extensors and flexors), problems with these muscles can cause a decrease in the neuro drive in their functional antagonists. This can lead to supportive muscles taking over, and may cause a strain/ injury in those muscles.
Injuries that can occur because of a tight or weak pelvis are ones such as hip anteversion which causes the femur to more internally rotate which then causes the foot to be more turned in towards the midline down the chain. Hip retroversion causes the opposite problem, which is hip external rotation and causes lateral rotation of the femur and then the foot. Also, if the pelvis is anteriorly tilted, it can cause Illipsoas syndrome, which affects the gluteus maximus, which causes the hamstrings to take over hip extension, which can then lead to a hamstring strain. Other injuries that can be caused by an unstable pelvis are plantar fasciitis, IT band syndrome, and patellofemoral pain.
A stable LPHC also affects the upper body through the kinetic chain such as in scapular stability. This occurs because the lower body is able to generate about 55% of the force in an upper body movement, such as in throwing. This idea can be related back to my previous blog about rowing technique in that the force produced by the legs is translated up the kinetic chain through the LPHC to the upper body during the drive phase of the stroke. With efficient functionality of the entire lumbopelvic hip complex, one can maintain a strong, stable, and functional base for all movements (Oliver, 3069).
Kibler, W. Ben. “The Role of The Scapula in Athletic Shoulder Function.” The American Journal of Sports Medicine 26.2 (1998): 325-337.
Oliver, Gretchen D., et al. “Muscle Activation of Different Core Exercises.” The Journal of Strength & Conditioning Research 24.11 (2010): 3069-3074.