Low Back Pain: A Functional Perspective
By Mike Clark, M.S., P.T., C.S.C.S.
Sports and work-related back injuries are becoming a major problem, almost an epidemic. Low back pain is becoming increasingly common in both the recreational and elite athlete. And, in the general population, 70-80% has low back pain currently or has suffered from multiple episodes of low back pain.
Traditionally sport medicine specialists have focused on isolated structures in the low back that have been damaged. However, from a functional perspective, the specialist must address the abnormal biomechanics (muscular and articular) and neuromuscular deficits that create excessive comprehensive, translational and shear forces throughout the lumbar spine that cause tissue overload and injury.
Focus on Function
Function has become a buzzword. Function is integrated multi-dimensional movement involving acceleration, deceleration and stabilization. Athletes must train and rehab in a functional environment to adequately develop functional strength and neuromuscular efficiency. Functional strength is the ability of the neuromuscular system to produce concentric force, isometrically stabilize and eccentrically decelerate the kinetic chain in all three planes of movement efficiently during functional activities. Neuromuscular Efficiency is the ability of the neuromuscular system to allow the prime movers, synergists, stabilizers and neutralizers to work synergistically as an integrated function, allowing structure and functional efficiency. The goal of functional reconditioning and training is to provide athletes with optimum levels of functional strength, neuromuscular efficiency, and core stability for efficient multi-dimensional movement. Movement is not an isolated event that occurs from a neutral lumbar spine position in one plane of motion. However, movement is a complex, interdependent series of events that involves synergists, stabilizers, neutralizers and prime movers all working together to accelerate, decelerate and dynamically stabilize our center of gravity over our base of support. The most important link in the kinetic chain is the core. This is where all movement begins. A well-developed core allows for improved forces output, neuromuscular efficiency and decreased incident of overuse injury.
Most athletes have developed the functional strength and power in their prime movers that will allow them to become successful in their particular sport, but they have not adequately developed functional stabilization strength or neuromuscular control of the lumbo-pelvic-hip complex to allow structural or functional efficiency. Lack of stabilization strength and neuromuscular control leads to decreased performance and overuse injuries.
Kinetic Chain Concepts
The kinetic chain is made up of the myofascial, articular, and neural systems. All three systems work as an integrated functional unit to provide structural and functional efficiency during functional activities. Dysfunction in any system leads to compensations and adaptations in the other systems. Adaptive, compensatory patterns develop, leading to tissue overload and injury.
If one muscle is weak (Gluteus Maximus), than other muscles (Erector Spinae, and Hamstrings) compensate in attempts to maintain functional movements. This concept where one or more synergists take over function for a prime mover is called Synergistic Dominance. In the above example there would be increased compressive forces in the lumbar spine secondary to increased synergistic muscle activity without adequate stabilization. If one muscle is tight (Psoas) than the functional antagonistic muscles (gluteus maximus, transverse abdominus, internal to increased compressive and translational forces.
This is the concept of reciprocal inhibition.
The CNS is the command center that controls and regulates all movements. The CNS directs preprogrammed patterns of movement that can be modified in countless ways to react appropriately to gravity, ground reaction forces, and momentum. This is an important concept. To optimally recondition the injured athlete, all of the core muscles must be trained in all three planes of motion utilizing methods of acceleration, deceleration, and dynamic stabilization.
Kinetic Chain Dysfunction is a complex interaction of all systems. For example, research has demonstrated following an ankle sprain, the gluteus medius and gluteus maximus are inhibited. This decreased the ability to decelerate frontal and transverse plane forces during functional movements. Furthermore, current research has demonstrated that the transverse abdominus is inhibited following low back pain. It has been established that the transverse abdominus is a major intrinsic stabilizer of the lumbar spine. The TA is preferentially recruited during functional movements to prevent rotational and translational stress in the lumbar spine. Most athletes are unable to adequately fire their TA during functional activities. Instead, most athletes rely on extrinsic muscles (Psoas, Erector Spinae, Superficial Abdominals) to provide dynamic stability. This synergistic dominance leads to poor posture, inadequate stabilization, decreased neuromuscular control, tissue overload, and eventually injury.
A comprehensive evaulation must be performed on each athlete to determine the cause of their low back pain. Muscle imbalances, joint dysfunctions, and abnormal neuromuscular control must be assessed systematically throughout the kinetic chain. A functional evaluation must also be implemented to determine core stabilization, strength, neuromuscular control, and power.
Core Stabilization Progression
A functional core stabilization progression is designed to optimally recruit the muscles that stabilize the lumbo-pelvic-hip complex and develop neuromuscular efficiency. The fundamental principles of reconditioning the injured athlete include: Simple to Complex, Known to Unknown, Low Force to High Force.
Static to Dynamic Specific functional exercises should be utilized to develop optimal core stability. All exercises should be safe, challenging, stress multiple planes of motion, incorporate a multisensory approach, and be derived from fundamental movements. Each athlete should be placed on a dynamic flexibility routine to self-correct all muscle imbalances. The athlete should also receive an integrated manual therapy approach to address joint dysfunctions and myofascial adhesions.
Michael Clark, M.S., P.T., C.S.C.S., combines his training as a Physical Therapist with the knowledge he has gained conditioning people. He is a highly respected professional in the field. A comprehensive list of reference texts is available upon request.