By Dr. Micheal Clark and Aaron Nelson
Micheal Clark, DPT, MS, PT, NASM-PES, is the President and Aaron Nelson, MS, ATC, NASM-PES, is an Athletic Trainer at the National Academy of Sports Medicine. Nelson is also Head Athletic Trainer for the Phoenix Suns. They can be reached at: www.nasm.org.
Training & Conditioning, 15.7, October 2005, http://www.momentummedia.com/articles/tc/tc1507/tothelimit.htm
The initial diagnosis was simple: a strained left hamstring. The athlete was a nine-year veteran in the NBA, no stranger to physical play, and eager to get back on the court.
He complained of left proximal hamstring pain during all functional activities. There was pin-point tenderness in the proximal attachment of the hamstring complex near the sacrotuberous ligament. And the athlete had severe limitations in ROM, strength, and function.
A traditional course of rehab was initiated, including modalities, stretching, and strengthening, but the athlete was not showing improvement. He had missed six games during the traditional rehabilitation before being referred to us for further treatment.
In the NBA, players are pushed to their physical limits. Games almost every night, physical play, and a long season leave bodies sometimes in need of specialized rehab and reconditioning. This athlete fit that description to a tee. His hamstring pull was affecting many more muscles, joints, and ligaments in his body than just his hamstring, and he needed a full body analysis and rehab program to get back on the court.
Our philosophy in treating athletes is to take into account the interrelated workings of the human body to identify the underlying factors that might be causing pain. Before we tell you more about this athlete’s case study, let us explain our rationale:
Movement represents the integrated functioning of many systems within the human body, primarily the muscular, articular, and nervous systems. These systems form an interdependent triad which, when operating correctly, allows for optimum structural alignment, neuromuscular efficiency (coordination), and movement. Each of these outcomes is important in establishing normal length-tension relationships, which ensure proper length and strength of each muscle around a joint, known as muscle balance.
Muscle balance is essential for optimal recruitment of force couples to maintain precise joint motion and ultimately decrease excessive stress placed on the body. All of this translates into efficient transfer of forces to accelerate, decelerate, and stabilize the interconnected joints of the body—what many refer to as the kinetic chain.
However, for many reasons, such as repetitive stress, impact trauma, or immobilization, dysfunction can occur in the muscular, articular, or nervous systems. And if one or more of these systems are altered, muscle balance, muscle recruitment, and joint motion will follow suit, leading to changes in structural alignment, neuromuscular control (coordination), and movement patterns. The result is a human movement system impairment.
When a human movement system impairment exists, some muscles are overactive, some muscles are underactive, and joints are affected. The terms “overactive” and “underactive” refer to the activity level of a muscle relative to another muscle or muscle group, not necessarily to its own normal functional capacity.
Any muscle, whether in a shortened or lengthened state, can be underactive or weak. Underactive muscles exhibit less than optimal force production capabilities. This results in an altered recruitment strategy and ultimately an altered movement pattern. Alterations in muscle activity will change the biomechanical motion of the joint and lead to increased stress on the tissues of the joint, which eventually results in injury.
When a muscle is overactive, it is working harder than it should and fatigues more easily. It can then cause tenderness, which decreases performance. This may add stress to the tissues and lead to the joint being pulled out of position. (See “Under & Over” below for a look at muscles prone to over- and underactivity.)
To begin our evaluation of the injured NBA athlete, we gave him a comprehensive “Human Movement System” assessment. The aim of this is to reveal any underlying muscle imbalances, joint dysfunctions, and neuromuscular inefficiency that could be causing the lack of progress and persistent complaints of pain and stiffness.
The player first underwent an Integrated Movement Assessment (Body Map) to determine transitional movement efficiency, integrated flexibility, and neuromuscular efficiency. This evaluation required the athlete to perform an overhead squat while we watched and analyzed his ability to perform integrated kinetic chain movements.
In most cases, if an athlete has proper flexibility, balance, core strength, functional segment strength, and neuromuscular efficiency, he or she should be able to squat to a parallel position or below without compensating at the foot/ankle, knee, lumbar spine, or upper extremity. However, if the athlete has altered length-tension relationships (overactivity of a muscle or muscle group), altered force-couple relationships (underactivity of a muscle or muscle group with compensation from a secondary synergist), or joint hypomobility/hypermobility, we will see abnormal movements. We carefully look at three areas when assessing these problems:
Foot/ankle: We look for any signs of pronounced eversion, which may be caused by overactive peroneals and lateral gastrocnemius and underactive posterior tibialis, anterior tibialis, and medial gastrocnemius. It may also be a result of decreased mobility of the talus. In addition, we check for excessive external rotation, which can be caused by overactivity in the soleus, lateral gastrocnemius, and short head of the biceps femoris and underactivity in the medial gastrocnemius, medial hamstring complex, gracilis, and sartorius. It can also be linked to decreased mobility of the talus and proximal tibio-femoral joint.
Knee: Here, we assess any problems
with abduction, which may be caused by overactivity in the piriformis, gluteus medius, and biceps femoris and underactivity in the adductor complex and medial hamstring complex. Another cause is decreased mobility in the hip (iliofemoral) joint. We also look for problems with the knee’s adduction, which can be caused by overactivity in the adductor complex, medial hamstring complex, gluteus minimus, and tensor fascia latae (TFL) and underactivity in the gluteus medius and maximus. It also can be caused by decreased mobility in the talo-tibial joint and the iliofemoral joint.
Lumbo-Pelvic-Hip Complex: We evaluate for excessive extension, which can be caused by overactivity in the erector spinae, latissimus dorsi, and psoas and underactivity in the rectus abdominus, external obliques, and intrinsic spinal stabilizers. It can also be caused by decreased mobility in the lumbar facet joints. Problems with flexion can be a result of overactivity in the rectus abdominus, external obliques, hamstrings, and gluteus maximus and underactivity in the erector spinae, psoas, latissimus dorsi, and intrinsic spinal stabilizers.
We also tested ROM through a goniometric assessment, performed manual muscle testing, and conducted positional kinematics to test relative joint position. In addition, we performed soft tissue palpation and neuro-dynamic testing.
In evaluating this specific athlete, we found that his left foot everted and, at the knees, the left femur adducted and internally rotated. His ROM tests indicated a handful of positional problems with the left side of his lower torso:
• Dorsiflexion was eight, with normal being 20.
• Hamstring 90/90 was 55 degrees, with normal being 10 degrees.
• Hip internal rotation was nine, with normal being 45.
• Hip extension was 19 with tightness, with normal being -5.
• All of the above tests were also inferior to his right side scores.
His manual muscle tests (using Daniels and Worthingham criteria) were at three/five for the left posterior tibialis, left medial gastrocnemius, and left gluteus medius. Normal would be at five.
Positional kinematics showed a decreased posterior and lateral glide of the talus and decreased flexion and rotation of the left sacral base. Our soft tissue palpation revealed tenderness greater than 7/10 in the left soleus, left short head of the biceps femoris, left gluteus minimus, left piriformis, and left adductor magnus. Neuro-dynamic testing showed a positive slump test, with problems indicated at the left sciatic nerve in the peroneal branch.
Most concerning to us, to start, was the left foot eversion, limited ankle dorsiflexion, and decreased muscle activation of the medial gastrocnemius and posterior tibialis. This combination can have a far reaching effect throughout the human movement system.
For example, when the ankle does not properly dorsiflex during functional movements (cutting, running, jumping, etc.), increased frontal and transverse plane movements occur throughout the human movement system. This can lead to increased femoral adduction and decreased internal rotation (which we did see during the assessment).
Lack of internal hip rotation of the iliofemoral joint causes increased frontal plane demand (femoral adduction). This causes a greater demand on the eccentric function of the gluteus medius (and this muscle tested weak during muscle testing).
If the gluteus medius is underactive, then other muscles in the hip compensate for the lack of force production in the gluteus medius through load sharing or synergistic dominance. This compensation includes overactivity in the TFL (frontal plane hip abduction and eccentric control of adduction). Overactivity of the TFL may then cause an anterior rotation of the iliosacral joint, which lengthens the gluteus maximus and may force the hamstrings (primarily the biceps femoris) to become more synergistically dominant. Since the bicep femoris attaches to the sacrum via the sacrotuberous ligament, an overactive biceps femoris can create unilateral extension and rotation of the sacrum. This chain reaction rang true for this particular athlete, as he had pain on the sacrotuberous ligament (ongoing back pain).
Underactivity of the gluteus medius may also lead to load sharing of the piriformis. An overactive piriformis decreases internal hip rotation and externally rotates the sacrum. Lack of iliofemoral internal rotation and lack of sacral flexion and right rotation may create increased mechanical tension through the sciatic nerve. This seemed to be the case, as the athlete had a positive slump test on the left sciatic nerve.
Therefore, lack of ROM (decreased hip extension leads to overactive TFL, decreased hip internal rotation leads to overactive piriformis, decreased knee extension leads to overactive biceps femoris), lack of muscle activation (underactive gluteus medius), and altered joint arthrokinematics (decreased posterior glide of the talus, hip internal rotation, and sacral extension) may have lead to increased demand on this athlete’s low back.
This athlete received a comprehensive manual therapy approach to correct joint and muscle imbalances. The techniques used included the following:
Soft Tissue Release Therapy: The goal here was to increase soft tissue extensibility in those muscles that had been in an overactive, shortened position. The muscles treated included the left soleus, lateral gastrocnemius, short head of biceps femoris, vastus lateralis, TFL, piriformis, and adductor magnus.
Active Release Therapy: We used ART to increase soft tissue extensibility and antagonist activation in the same muscles mentioned above. As an addition to this treatment, we used the athlete’s voluntary contraction of the antagonist to stretch the tight muscle. For example, we had the athlete contract the anterior and posterior tibialis as we performed active release on the lateral gastrocnemius and soleus. This allowed us to develop improved neuromuscular control in the antagonist muscles in this new ROM.
Joint Mobilization Techniques: To improve joint mobility in those segments with limited mobility we used basic joint mobilization techniques (Maitalind and Mulligan). The joints treated included the left talus (posterior mobilization), the left iliofemoral joint (lateral traction), and the left sacroiliac joint (flexion/rotation).
Neuromobilization: To increase neural tissue mobilization of the sciatic nerve, we conducted neural-flossing, which aims to stretch the connective tissue around the affected nerve. The athlete began in a sitting position while we put pressure on the left sacroiliac base. He put his left leg onto a treatment table (hip flexion, knee extension, femoral adduction, femoral internal rotation). We then had the athlete extend his lumbar spine and dorsiflex his left foot as we applied force to his left sacroiliac base. We repeated this technique for 10 reps and held each rep for two seconds.
Along with manual therapy, this athlete was given a comprehensive corrective exercise program. The focus of the program was to inhibit and lengthen overactive muscles, activate underactive muscles, and then integrate the new ROM and muscle activation into functional movements.
We started the athlete with self myofascial release using a foam roll, which inhibits overactive muscles. He performed one rep of 30 seconds on each tender point in the left soleus, left lateral gastrocnemius, left biceps femoris, left TFL/ITB, and left piriformis. To lengthen overactive muscles, he did two reps for 30 seconds of static stretching on each of the same muscles.
To address the underactive muscles, we used muscle activation, which helps to improve neuromuscular efficiency by specifically focusing on intra-muscular coordination. Specific contraction of each muscle in the synergy helps prevent synergistic dominance from a stronger muscle in the synergy. It also serves as a form of active isolated flexibility and preparation for the integrated strength exercises that will follow. Each muscle activation exercise was performed for two sets of 20 reps on the left posterior tibialis, left medial gastrocnemius, and left gluteus medius.
Next, the athlete performed integrated neuromuscular training, including core, balance, and reactive training. For core training, he performed an iso-abdominal series (2x30-second holds) prone with isometric holds and then sidelying. He also completed a stability ball core series (2x15) of bridges, crunches, and prone cobras.
For neuromuscular stabilization exercises, he did single-leg stability with multi-planar reaching (3x10 in each plane of motion). Exercises were performed following a progression using unstable surfaces to facilitate increased proprioceptive activity. We started with a foam roll, moved to an Airex pad, and then to a pivot plate. These exercises by themselves are not “functional,” but they prepare the athlete for transitional and dynamic movements.
We also included reactive neuromuscular stabilization exercises. The athlete performed multi-planar single-leg hops for balance. The protocol was 2x10 in each plane of motion (frontal, sagittal, and transverse).
Lastly, we gave him a total body integrated strength exercise program to perform. Included was a tube walking series in which we put tubes around the ankles and had him take 10 steps (2 reps). These tube exercises involved side-to-side walking in an athletic stance with an emphasis on perfect form (feet straight ahead and no hip-hiking) and front-to-back walking straight and diagonal.
BACK ON TRACK
The athlete progressed nicely and was able to return to full function with no pain by the end of the rehab program. On his left side, he increased his dorsiflexion to 20 (a 250 percent improvement), his hamstring 90/90 to 30 (a 150 percent improvement), his hip internal rotation to 45 (a 500 percent improvement), and his hip extension to 9 (a 211 percent improvement). In terms of strength, all muscle testing scores returned to 4+ or greater. All joint positions were restored to normal limits. And his slump test was negative.
After missing those initial six games following a traditional rehab progression, he was able to play within three treatment sessions of manual therapy and corrective exercise. The rehab process took us three weeks, and he continued the reconditioning phase throughout the rest of the season to prevent reoccurence of the injury.
Athletes often suffer from overuse injuries. This case study demonstrates that human movement impairments may cause tissue overload in an isolated anatomical location (e.g., hamstring) but the neuro-musculo-skeletal imbalances may need to be identified and corrected to fully rehabilitate, recondition, and return an athlete to the game. If executed correctly, this type of approach can save the athletic trainer and athlete a lot of time and pain.
Under & Over
The following shows which muscles are typically prone to under- and overactivity:
•Vastus Medialis Oblique (VMO)
•Deep Cervical Flexors
•Tensor Fascia Latae