The complexity of Lumbo Pelvic Hip Complex and it's importance

The lumbo-pelvic-hip complex (LPHC) is a region of the body that has a massive influence on the structures above and below it. The LPHC has between 29 and 35 muscles that attach to the lumbar spine or pelvis. The LPHC is directly associated with both the lower extremities and upper extremities of the body. Because of this, dysfunction of both the lower extremities and upper extremities can lead to dysfunction of the LPHC and vice versa. 

Collectively, these structures anchor many of the major myofascial tissues that have a functional impact on the arthrokinematics of the structures above and below them. Above the LPHC are the thoracic and cervical spine, rib cage, scapula, humerus, and clavicle. These structures make up the thoracolumbar and cervicothoracic junctions of the spine, the scapulothoracic, glenohumeral, acromioclavicular (AC), and sternoclavicular (SC) joints. Below the LPHC, the tibia and femur make up the tibiofemoral joint, and the patella and femur make up the patellofemoral joint. The fibula is the attachment site of the biceps femoris, which originates from the pelvis. The tibia, fibula, and talus help to form the talocrural (ankle) joint. Collectively, these structures anchor the myofascial tissues of the LPHC such as the biceps femoris, medial hamstring complex, and rectus femoris. These bones and joints have a functional impact on the arthrokinematics of the LPHC. There are a number of muscles in the upper and lower extremities whose function may be related and have an effect on the LPHC. As with all muscles, it is important to restore and maintain normal range of motion and strength, as well as eliminate any muscle inhibition to ensure joints are operating optimally.

Common LPHC Injuries and Associated Movement Deficiencies

Many of the common injuries associated with the LPHC include low-back pain, sacroiliac (SI) joint dysfunction, and hamstring complex, quadriceps, and groin strains. However, the body is an interconnected chain, and compensation or dysfunction in the LPHC region can lead to dysfunctions in other areas of the body. Moving above the LPHC, common injuries are often seen in the cervical-thoracic spine, ribs, and shoulder, which can stem from dysfunction in the LPHC. Moving below the LPHC toward the knee, common injuries include patellar tendinosis (jumper’s knee) and iliotibial band (IT-band) tendonitis (runner’s knee) as well as anterior cruciate ligament (ACL) tears. At the foot and ankle, common injuries that can stem from the LPHC include plantar fasciitis, Achilles’ tendinopathy, and medial tibial stress syndrome).

As previously stated, the LPHC has a great influence on the rest of the kinetic chain and vice versa. For instance if there is a lack of ankle dorsiflexion owing to an overactive or tight gastrocnemius and soleus, the LPHC will be forced to increase forward flexion to alter the body’s center of gravity to maintain balance. The underactivity of the erector spinae and gluteus maximus to maintain an upright trunk position produces the compensation of an excessive forward lean. The gluteus maximus and latissimus dorsi along with the thoracolumbar fascia work synergistically to form the posterior oblique subsystem. As a compensatory mechanism for the underactivity and inability of the gluteus maximus to maintain an upright trunk position, the latissimus dorsi may become synergistically dominant (overactive or tight) to provide stability through the trunk, core, and pelvis. Because the latissimus dorsi crosses the inferior angle of the scapulae and inserts onto the humerus it can alter the rotation of the scapula and instantaneous axis of rotation of the humeral head within the glenoid fossa. The erector spinae, sacrotuberous ligament, biceps femoris, peroneus longus, and anterior tibialis work synergistically to form the deep longitudinal subsystem. With both the anterior tibialis and erector spinae working at a submaximal level, the biceps femoris may become overactive to help maintain stabilization of the LPHC. This, however, will alter the position of the pelvis and sacrum and affect the sacroiliac and iliofemoral joints. The latissimus dorsi may also become overactive or tight to provide stability through the pelvis and extension of the spine for the inability of the erector spinae to maintain an upright trunk position. The latissimus dorsi attaches to the pelvis and will anteriorly rotate the pelvis, which causes extension of the lumbar spine. From an injury perspective, the increased hip or spinal flexion can lead to excessive stress being placed on the low back, resulting in low back pain. It can also lead to increased stress in the hamstring complex and adductor magnus, which may be trying to compensate for a weakened gluteus maximus and erector spinae complex to stabilize the LPHC, and result in hamstring complex and groin strains. The rectus femoris, being one of the primary hip flexors, tends to be overactive in this scenario. This can decrease its ability to lengthen during functional movements and lead to quadriceps strains as well as knee pain. Overactivity or tightness of the latissimus dorsi can affect the shoulder and upper extremities leading to a variety of shoulder and upper extremity injuries.

Spine Stability Controversy

Exercises to improve spine stability are widely used in rehabilitation and prevention programs. However, there is ongoing debate on which muscles or muscle groups (local or global) to address as well as exercise goals during spine stability training. This is in part because of the assumption that intervertebral stability is automatically achieved and that exercises should focus on improving lumbopelvic stability to achieve spine stability. There are two primary differences in the approaches toward spine stability training. First, there are differences in the target muscle groups for the prescribed exercises, specifically, exercises for local versus global musculature. Second, there are differences in the type of exercises performed in terms of exercises geared toward improving strength and power (abdominal bracing) versus exercises that focus on improving neuromuscular control (abdominal drawing in maneuver). The traditional approach to spine stability training uses exercises that focus on the global stabilizers, but not the local stabilizers. This is primarily based on research that suggests that the global muscles are most important for spine stability. However, this research assumes that intervertebral stability is achieved. Both local and global muscles contribute to spine stability. Therefore, it is critical that exercises for spine stability address both local and global stabilizers. Thus, both bracing and drawing in can ultimately improve spine stability. Because drawing in can influence both intervertebral stability and lumbopelvic stability and because lumbopelvic stability is dependent on intervertebral stability, use of the drawing in maneuver to train the local muscles and improve intervertebral stability may be considered the starting point for a spine stability training program, then progressing to abdominal bracing.

The LPHC operates as an integrated functional unit, enabling the entire kinetic chain to work synergistically to produce force, reduce force, and dynamically stabilize against abnormal force. In an efficient state, each structural component distributes weight, absorbs force, and transfers ground reaction forces. This integrated, interdependent system needs to be appropriately trained to enable it to function efficiently during dynamic activities. Because of the many muscles associated with the LPHC, dysfunction in this region can potentially lead to dysfunction in both the upper and lower extremities, and dysfunction in either the upper or lower extremities can lead to LPHC dysfunction. For this reason it becomes a crucial region to assess and will most likely be a region that will need to be addressed in most individuals with movement deficits.

REFERENCES

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2. Grieve GP. Lumbar instability. Physiotherapy. 1982

3. McGill SM. Low back stability: from formal description to issues for performance and rehabilitation. Exerc Sport Sci Rev. 2001