The purpose of this article is to teach integrated exercises which recruit the "inner unit" musculature or the body's natural weight belt mechanism. The objective will be to activate these key spinal stabilizing muscles during full body integrated movement patterns. In review, the inner unit is a term describing the synergy between the transversus abdominus, posterior fibers of the internal obliques, multifidus, lumbar portions of the iliocostalis and longissimus, multifidus, pelvic floor muscles, and diaphragm.(1) This group is activated as the lower abdomen is drawn inward toward the spine, thus creating a narrowed waistline. Many cues are given to help the client perform this action, such as; draw the belly button inward toward the spine or imagine someone pulling on a string behind your back that is attached to your belly button. The main responsibility of the deep corset musculature is to increase intra-abdominal pressure and provide joint stiffness and stability of the spine, pelvis, and rib cage.(2)
This activation helps to create a rigid internal cylinder so that we can optimally produce force, reduce force, and stabilize the lumbo-pelvic hip complex during functional on the feet multi-planar movement patterns. The larger superficial muscles core muscles such as the rectus abdominus, external obliques, quadratus lumborum, and erector spinae group are also activated during functional movement patterns and serve along with the inner unit musculature to maintain a rigid trunk position. They eccentrically decelerate trunk extension, rotation, and side bending so that the spine does not move into harmful end ranges. When performing many life or job activities, these muscles must work with the hips to create functional ground based rotational and twisting movements and serve as a link when transferring forces as seen in throwing and striking activities.
Teaching the body to properly integrate the entire lumbo-pelvic hip complex with the inner unit musculature and extremities in all three planes of motion is foundational to creating a functional core. This article will cover exercises performed in the saggital plane, the next article will include exercises in the frontal and transverse plane.
Before we move forward, we need to discuss the isolated approach to teaching activation of the inner unit musculature through the draw in maneuver. The activation technique of drawing the lower abdomen inward to activate the inner unit musculature has been detailed in the book "Therapeutic Exercises for Spinal Segmental Stabilization in Low Back Pain" by Richardson, Jull, Hides, and Hodges. The testing of function has been widely popularized and taught in excellent detail by Paul Chek through a PT on the Net article "The Inner Unit" and in his video series on Core Conditioning.
One may develop precise motor control of the draw in maneuver in the prone position or quadruped position as demonstrated in the sources above. This technique can be useful when learning to isolate the inner unit musculature, especially if the client has chronic low back pain or a diagnosed pathology. The goal for healthy individuals, with no history of chronic low back pain, is to integrate this action within a functional movement pattern in the standing position. The exercises covered in this article have a multiple benefits; increased spinal stabilization ability along with core and pelvis control, increased strength of extensor muscles which help to restore posture, increased hip-leg-back strength and motor control through squatting and lunging patterns, and increased shoulder girdle strength and mobility aimed at restoring posture.
I'd like to thank physical therapist and lecturer Gary Gray for opening my mind in the area of kinetic chain integration. I learned the split stance to overhead raise movement pattern during Gary's seminar on shoulder and scapular reaction through Wynne Marketing. The overall goal of learning the exercises was to teach patterns of movement versus isolated rotator cuff exercises restore strength, mobility, and stability of the shoulder girdle in all three planes of motion. I have emphasized an awareness of the deep corset activation or core/pelvis control for this article along with modifications for progression.
The first integrated pattern we will discuss is what I call the squat and reach to overhead raise. The squat is progressed from a 1/4 depth, 1/2, 3/4, and full range. The main pre-requisite before descending to a lower squat depth is maintaining a neutral spine with proper rib cage, head, and neck posture. I like to start with raising only one arm overhead, as better core control is usually demonstrated. When using this pattern for shoulder/scapular rehabilitation, a one arm approach is ideal as one limb is frequently injured.
To start the exercise, assume a squat stance, draw the lower abdomen in slightly and lower the hips to a 1/4 squat position or lower if proper squatting mechanics are displayed. The trunk should hinge slightly forward from the hips with the arms hanging naturally as if holding a golf club. It is important to maintain a neutral lumbar, thoracic, and cervical position as would be seen when squatting properly. Next, instruct the client to raise one arm out and upward overhead in a straight arm fashion. The thumb should point back during the overhead raise while simultaneously extending the knees and hips. The focus of the exercise is to draw the lower abdomen in tight as the arm raises overhead. We also want to make sure that the rib cage is lifted so that the rectus abdominus and external obliques are in a lengthened position. With the arm overhead, we can place our fingers of one hand just below the clients navel and the fingers of the other hand along the sides of the lumbar spine opposite to the belly button and encourage the draw-in maneuver by gently pressing in with both hands. Have the client hold this position for a couple seconds and key in on the deep corset action. The arm should then be bent and the dumbbell lowered to the shoulder, and back down to the starting position.
|1/4 Squat to 1 Arm Overhead Raise-start
||1/4 Squat to 1 Arm Overhead Raise-end
If the client has ideal thoracic mobility and normal lattisimus dorsi and pec length, the arm should be able to rise directly over the shoulder with the knuckles facing the ceiling and thumb back. If the client is limited in thoracic extension or if there is a present shoulder limitation due to injury, only raise the arm to the height where they are pain free. A neutral orientation of the pelvis, lumbar and cervical spine should be maintained. A natural tendency, for individuals with poor core control or lack of shoulder girdle mobility, is to push the abdominal wall outward which is accompanied by the lumbar spine extending beyond neutral into a sway back posture. The same hand placement as mentioned above should be utilized to help the client become aware of a neutral pelvis alignment.
This exercise should be used for strength-endurance purposes with a rep range of 12-20 or even higher if a shoulder injury is present. I recommend starting with body weight when teaching the pattern, progress to light dumbbells or wrist weights using one pound increment increase. One should progress from one arm to two arms if there is equal strength and mobility on each side. Adequate core control must be demonstrated with the one arm variation before attempting the exercise with two arms. For an advanced variation of the one or two arm raise, the exerciser may raise onto the balls of the feet as the arms are raise overhead. Again, a lower squat depth can also be utilized as long as proper squat mechanics are adhered to.
|1/2 Squat to 2 Arm Overhead Raise-start
||1/2 Squat to 2 Arm Overhead Raise-end
The next pattern is the stationary split stance with a reach to overhead raise. This exercise lessons the base of support and increases the need for hip, knee, ankle stabilization and core control. The reach should progress from a 1/4 lunge, 1/2, 3/4, and parallel thigh position.
To start the exercise, have the client split the stance enough for proper hip loading to occur with the reach pattern (see photo). Have the client stand upright while remaining on the ball of the back foot. Draw the lower abdomen inward slightly and slowly reach with the hand opposite to the lead leg (handshake position) toward the ground and slightly in front of the lower leg to promote glute max loading. The knee should move past the ankle and over the mid-foot to properly load the hip. Proper knee cap tracking should be monitored as it should remain in alignment with the middle of the foot. The glute medius is a major stabilizer and is responsible for keeping the knee tracking properly. If the hip, knee, and foot roll inward, place your fingers along side of the lateral knee and instruct the client to gently press outward until the knee aligns over the mid-foot.
The client should look down as if reaching to pick up an object and the rib cage should move progressively closer to the upper thigh of the lead leg as the reach progresses downward. The lumbar spine should be kept neutral when performing the 1/4 to 1/2 lunge variation and allowed to naturally round if reaching lower. Maintaining neutral spine mechanics is an important factor if training someone with any spinal pathology. The trunk should remain long and rigid during the initial stages of trunk flexion. We should cue the client to keep the chest up and not round out the upper back. The back knee should only bend 10-20 degrees as the front hip and thigh musculature receive the majority of the load.
Now that we have accomplished proper deceleration, the client should raise the arm overhead while keeping it straight. Instruct the client to reach out and up while simultaneously extending the hip and knee of the lead leg while rising high on the ball of the back foot. The client should progressively draw the lower abdomen in tighter as the arm raises overhead. We want them to visualize being pulled up to the ceiling and assume their best posture. The same faulty postures and mechanical faults as previously mentioned in the squat to overhead reach must be monitored and corrected.
|Stationary Split Stance & Reach Down to 1 Arm Overhead Raise- start
||Stationary Split Stance & Reach Down to 1 Arm Overhead Raise- end
Again, strength endurance is the goal for this exercise. Deconditioned clients may experience hip fatigue before the desired reps are achieved. Once fatigue or breakdown of stability and posture occur, simply switch the lead leg. Repeat this in an alternating manner until the desired repetitions are achieved.
The last variation performed in the saggital plane involves much more dynamic stability of the entire kinetic chain. This exercise starts with the feet together and involves a step back and reach forward simultaneously. It is important to have the ball of the back foot contact the ground as the front knee assumes a 1/4 lunge position. The advanced variation incorporates hip flexion with the overhead raise. The ball of the back foot should leave the ground as the arm starts to raise overhead. The hip should complete flexion (crane position) as the arm finishes overhead. Obviously, this exercise requires precise motor control and a high degree of balance. When teaching this variation, promote a very slow and controlled tempo to give the stabilizers a chance to perform their duties.
Dynamic Split Stance & Reach Down to 1 Arm Overhead Raise- end
The exercises are perfect to implement in the beginning of any strength training program. They will serve as a great full body warm-up for our intermediate to advanced clients and as great strengthening exercises for the deconditioned population. After performing a set or two of the exercises in the beginning of a program, I have regularly seen clients exhibit a greater likelihood of naturally activating this important mind-muscle connection while performing other functional movement patterns.
- Richardson C., Jull G., Hodges P. and Hides J. Therapeutic Exercise for Spinal Segmental Stabilization in Low Back Pain- Scientific Basis and Clinical Approach.
- London, New York, Philadelphia, Sydney, Toronto: Churchhill Livingstone, 1999
- Chek P. The Inner Unit Published at www.PTontheNet.com