Gray Cook, MSPT, OCS, CSCS
Director of Sports Medicine
Rehabilitation Services of Danville
108 Holbrook Street, Ste. 101
Danville, VA 24541
Research data has shown us that the three most important groups of muscles for active spinal stabilization are the oblique muscles, both internal and external, the transverse abdominous muscles, the multifidi and erector spinae muscles. When working in unison these muscles perform dynamic splinting of the lumbar spine through both stabilization at their attachments and intra abdominal pressure changes. The one problem that exists in training the lower abdominal musculature, multifidus musculature, and also performing active mobility techniques for the hips (to increase range of motion) is the fact substitution often occurs. Actually the substitution is usually the reason for lumbar dysfunction in the first place. Since it has become a frequent movement pattern for the patient with lower lumbar dysfunction it is extremely hard to make sure this substitution does not occur in an unsupervised exercise program. Locking techniques have been employed to minimize this substitution however they to are sometimes unsuccessfully employed by the patient without supervision. The BackSystem3 has allowed sufficient protection for the lumbar spine while improving hip mobility. The fact that the machine uses anatomical locking techniques in conjunction with active mobility techniques of the hip and pelvic region allows it to create both active and passive ranges of motion, which may compliment and even increase the effectiveness of home programs where supervision is minimal and equipment is scarce. It is very important for the clinician to understand that when a new piece of equipment is introduced it can not become both the treatment and the evaluation. Many people will respond to a full stretching regime on the BackSystem3 however statistically speaking the patient’s subjective report that they feel more flexible can not be used as objective clinical criteria. Therefore, I recommend that the evaluation techniques performed and standardized by Florence Kendall, Shirley Sahrmann, Stanley Paris, and other orthopaedic and manual physical therapists should be used to identify such muscular imbalances. A thorough evaluation can then be followed by a specific prescription of active and passive mobility exercise on the Back System3 locking device. I refer to the BackSystem3 as a locking device because as a manual therapist I see excellent potential for isolation of movement and specificity of training.
It has often been said that the definition of an athlete is one who has the ability to manipulate his/her body weight in space. Something as simple as gravity resisted hip adduction while in side-lying may seem like a basic movement, however, many professional and college athletes are unable to perform this movement. If lumbar and pelvic movements are restricted, it may create a substitution syndrome causing tight abductors and weak adductors thus leading to excessive lumbar motion. As physical therapists we often train weak muscles with resistance but this may be improper since we have already demonstrated the inability to even lift the extremity against gravity with all other substitutions removed. Therefore, no resistance is employed when performing muscular training with the BackSystem3 device.
Clinical observation of toddlers and infants in an orthopaedic and physical therapy practice has allowed me to observe the amount of flexibility we are born with in contrast to a more prevalent adult orthopaedic outpatient in the sports medicine population. Even when watching the infant and toddler sleeping with their knees tucked under their abdomen and their chest lying on the mattress we are not observing a feat of spinal flexibility but of hip flexibility because very often they are able to maintain a flat or lordotic lumbar spine with the successful hip flexion. Due to the abundant muscle mass surrounding the hip joint and the fact that we all are victims of sedentary life style hip mobility is lost with age. Not as a direct correlation with age but as a result of our increasing inactivity. We also as a general population in North America seldom perform a squat movement not with weights in a gym but in everyday life as opposed in sitting or kneeling.
The squat allows for dorsal flexion stretching specifically of the soleus musculature. The knee flexion stretching specifically of the single joint quadriceps and of course hip flexion. The lumbar motion required to squat only becomes excessive when there is a lack of hip flexion. Likewise, problems observed such as spondylolisthesis (forward movement of the body of one of the lower lumbar vertebrae on the vertebra below it, or upon the sacrum) and spondylolysis as well as other hyperextension disorders of the lumbar spine may be attributed to and are already being looked at by researchers as a secondary problem to loss of motion in hip extension. When active mobility of hip flexion is loss, the gluteal musculature usually becomes weak since the muscle is unable to explore its end range of movement. When it becomes weak, a substitution of the hamstring as a secondary hip extender usually is employed as a body continues to try to adapt and survive in situations where joint motion is lost. This may be a contributing factor to the over use and tightness often observed in a population with low back pain. Very often we implicate the hamstrings as being tight and automatically correlate that with a lumbar problem however if the hamstrings were used normally as a dynamic stabilizer in the lower extremity and not as a static extender of the hip, would this phenomenon occur?
Patient instruction for motion is often less frustrating for the clinician and the patient when using the BackSystem3. Nothing is more frustrating for both the patient and clinician than taking somebody with a subacute or acute lumbar problem and trying to teach the basic pelvic tilt motion. The patient has been substituting for a lack of pelvic tilt active mobility for a long time. In the presence of pathology pain, spasm and inflammation it is nearly impossible to teach a proper pelvic tilt and much more difficult to maintain a new motor program in which the pelvic tilt can be employed in other activities. Therefore, we need to reduce the variables that effect exercise such as substitution, uncomfortable positioning, and excessive resistance which sometimes may be the patient’s body weight or friction against the table when performing the pelvic tilt.
The BackSystem3 allows the pelvic tilt to be accomplished first passively and then with minimal instruction to become an active motion which can be easily integrated in a more upright and functional position. Just as awkward as the pelvic tilt may be for the individual with an acute lumbar spine problem, so to are some lumbar exercises. The lower abdominal exercise commonly employed in the lying position, while maintaining a lumbar flat or non-lordotic position is extremely hard for those with weak lower abdominals. The lower abdominal musculature usually is referred to as the oblique fibers that stabilized the pelvis in relation to the trunk and therefore help maintain eccentric control of extension of the lumbar spine. They also stabilized and assist when hip flexion is being performed. Very often when this exercise is employed in a lying position many people are only able to perform 2 to 4 reps with proper techniques. Afterward, a large amount of substitution and inefficiencies will occur. Physical therapists would not accept 2 to 4 repetitions for any other exercises. If only 2 to 4 repetitions are able to be performed the physical therapist will commonly reduce resistance or provide assistance with the activity so an appropriate amount of repetitions in a pain free range can be performed. However, we continually place patients in a bio-mechanical disadvantage and rarely give them a way to train the lower abdominal musculature successfully with a large enough amount of repetitions for muscle education in a new motor program to occur. The BackSystem3 allows for a more functional position. It is a less evasive and frustrating technique which allows not only for correct form, but a larger volume of repetitions to be performed. Any time a greater volume of exercise without pain or substitution is provided, a more appropriate situation is provided for muscle education.
Physical Therapists often criticize fixed axis exercise equipment due to its unrealistic arc of motion when considering the multiple axial characteristics of our synovial joints. Usually this criticism is most definite on an example like knee exercise where a hinge or axis for open chain knee extension and flexion is employed. The BackSystem3 does have a fixed axis however there is a large amount of distance between the fixed axis and the point of movement both in the hip and lumbar spine. This creates a gentle arc of motion that assists in replicating proper flexion of the hip and lumbar spine and extension of the lumbar spine. The other contributing factors that are sited for a smooth, safe and efficient stretching and exercise program on the BackSystem3 are: the fact that the lumbar spine is under a mild degree of contraction, the fact that the spine is upright in a functional position however unloaded due to hip position and upper extremity stabilization, proper and appropriate locking of the hip joints to minimize lumbar substitution in the presence of inflexibility, and the adaptability for active exercise with minimal substitution .