MRI is clearly the imaging study of choice to diagnose a lumbar disc herniation (Fig. 15-1). Plain radiographs should always be obtained to evaluate overall alignment, bony integrity, and stability. Patients who cannot obtain an MRI can be diagnosed using computed tomography (CT), CT myelogram, or CT discogram. These imaging tests are so sensitive that a discectomy is not indicated if a disc is not found to be herniated by one of these techniques. Other tests can include an electromyogram (EMG) or nerve conduction study.

Nonoperative treatment may include:

Surgical indications, as currently recommended by the North American Spine Society (NASS), include a definite diagnosis of ruptured lumbar intervertebral disc and the following23,24:

Conservative treatment consists of nonoperative management and careful observation. Some may benefit from a short trial of nonoperative treatment even after 8 weeks if no prior care was given. Failed conservative treatment is the most common indication for lumbar discectomy. Those who have not improved sufficiently and are not experiencing continued improvement might then be offered treatment by surgical excision of the disc. Such patients should be advised that this is an elective operation but that delay for longer than 3 to 6 months in the face of persistent and severe symptoms may compromise the best ultimate result.^24,25 The other indications (2 to 5) are exceptions to the 4- to 8-week rule. Excruciating pain may not be relieved by nonoperative means and may require earlier surgical decompression. Recurrent sciatica should also receive consideration for surgery: the chance of recurrent sciatica after the second episode is 50% and after the third episode is almost 100%.²⁵ An example of a significant neurologic deficit may be a foot drop or weakness that prevents normal posture, gait, or affects the patient’s profession or a particular skill. Any definite progression of neurologic deficit is an absolute indication for surgery. Cauda equina syndrome is relatively rare. It is reported in 1% to 3% of patients with confirmed disc herniations,^26,27 and it is an orthopedic or neurosurgical emergency. Features include rapid progression of neurologic signs and symptoms, bilateral leg pain, caudal sensory deficit, bladder overflow incontinence or retention, and loss of rectal sphincter tone with or without fecal incontinence.

NASS and the American Academy of Orthopaedic Surgeons have identified the following factors as absolute or relative contraindications for discectomy24,28:

After exposure of the interlaminar space and placement of the retractor, a high-speed burr is used to remove several millimeters of the cephalad lamina and 2 to 3 mm of the medial aspect of the inferior facet, taking care to leave at least a 6-mm bridge of bone at the level of the pars (Fig. 15-3). Once the cephalad lamina and medial aspect of the inferior facet have been removed, the ligamentum flavum is easily seen because its bony attachments are exposed. The ligamentum attaches at the very cephalad edge of the lower lamina, but approximately halfway up the upper lamina, and it attaches to the medial aspect of the superior facet. Thus the high-speed burr can be used relatively safely on top of the bottom half of the superior lamina, as well as the medial aspect of the inferior facet.

The ligamentum flavum is then released from the medial edge of the superior facet with a forward-angled curette. It can also be released from the undersurface of the upper and lower lamina (Fig. 15-4). It is safest to start the curette inferolaterally toward the superior aspect of the pedicle (caudal aspect of the foramen).

A ligamentum and epidural fat-sparing approach, performed by creating a flap of the ligamentum as described previously, decreases postoperative epidural broses and can improve results.^8,34 However, this can make it more difficult to get a good view of the nerve root. Certainly this is easier with a microscope than without one. The less-experienced surgeon may perform partial removal of these tissues. The ligamentum flap is also not recommended for large midline disc herniations (with or without cauda equina syndrome) and severely stenotic canals because the ligamentum itself occupies more room in the already severely compromised spinal canal and would also interfere with direct visualization for the delicate manipulation of the thecal sac.

After release of the ligamentum flavum, the medial edge of the superior facet is resected with 2- to 4-mm Kerrison rongeurs. This resection goes from the lower pedicle to the tip of the superior facet (Fig. 15-5). This medial facet resection decompresses any lateral recess stenosis at the level of the pedicle and up into the foramen, and it allows easy access to the lateral disc space. If needed, some of the lateral ligamentum flavum, particularly into the foramen, can be removed with the Kerrison rongeurs.

Bipolar cautery can be used at this time to cauterize any epidural bleeding over the lateral disc space, directly cephalad to the pedicle. We recommend finding the pedicle and then using it as a guide to release the epidural nonneural tissues above the disc space. At this point a nerve root retractor can be placed on the disc space, and the ligamentum flavum, epidural fat, and nerve root are retracted toward the midline, generally exposing the herniation (Fig. 15-6). Again, the bipolar cautery can be used to cauterize any epidural veins over the disc herniation. Any free large fragments of disc can now be removed (Fig. 15-7). If needed, a forward-angled curette can be used to scrape the inferior and posterior bony margins of the foramen, using a unidirectional pulling motion. Using the bony pedicle as a starting point ensures that the end of the curette does not include any neural tissue before scraping.

Frequently the annular defect of the disc herniation is all that is necessary to allow cleaning out of any loose nucleus pulposus inside the disc space, although the annulotomy can be enlarged with a No. 11 blade. The herniated nuclear material is then cleaned out with straight or angled pituitary rongeurs and small back-angled curettes. Care should be taken not to damage or curette the endplates. The annulotomy can be performed in various shapes, which are not discussed in detail here.36,44

One unresolved issue is how much disc to remove from the disc cavity. Removal of as much disc as possible implies curettage of the interspace, including possible removal of the cartilaginous endplates. Critics of this approach point out that no matter how long the surgeon works, it is impossible to remove all disc material in this fashion. They also argue that this method increases risk of damage to anterior visceral structures and increases risk of chronic back pain induced by conditions, such as sterile discitis and instability. Although some surgeons believe that extensive intradisc débridement decreases the rate of recurrent HNP, others refute that position.^36,45–47 In the end, the only reasonable prospective controlled study is Spengler’s,⁴⁸ which suggests that limited disc excision is all that is necessary. The advantages of limited disc excision are less trauma to endplates and less dissection, less nerve root manipulation, a lower prevalence of infection, reduced risk of damage to structures anterior to the disc space, and less disc space settling postoperatively (theoretically reducing the incidence of chronic back pain).

Once the decompression is complete, the entire surgical wound is thoroughly irrigated with antibiotic-containing irrigant. Any final bleeding is controlled with bipolar cautery, thrombin-soaked gel foam, or FloSeal hemostatic gel. After complete hemostasis and removal of all gel foam, the closure is performed in layers. Many attempts have been made to design substances to seal the laminotomy defect and prevent scar formation, including fat grafts, hydrogel, silicone, Dacron, and steroids.49 We simply prefer the ligamentum flap (Fig. 15-8).^5,8,25 The dorsal lumbar fascia is closed with No. 1-0 sutures, the subcutaneous layer with 2-0 sutures, and the skin with 3-0 subcuticular sutures. Using this ligamentum flavum–sparing approach, blood loss should be no more than 10 to 20 ml. With good hemostasis, drainage of the surgical wound is not necessary.

Many microdiscectomy procedures can be done on an outpatient basis.12,50,51 Most patients are encouraged to walk as tolerated. Sitting is also tolerated but may be more limited. Many return to work within 5 to 10 days, especially those with desk type of work. All patients are required to participate in lumbar physical therapy, primary stabilization, and mobilization beginning at approximately 4 weeks after surgery. Most athletes return to their normal athletic activities within 8 weeks after surgery. However, the postoperative course is variable, and return to normal activities depends on the patient’s overall medical condition, as well as neurologic and overall recovery.^16,52,53

High lumbar HNPs are uncommon (5%). When they occur they are likely to be foraminal or extraforaminal.25,54 Important skeletal anatomy in the higher lumbar spine for the spinal surgeon to be aware of includes the following: (1) the pars are narrower, and facet integrity is easily lost with excessive laminotomy; (2) the laminae are broader; (3) the interlaminar window is narrower; (4) the inferior border of the lamina overhangs more of the disc space; (5) at L1-L2, the conus cannot be retracted like the cauda equina at lower levels; (6) the nerve roots exit more horizontally and are less mobile; and (7) epidural veins may be more prevalent. At these levels, because of the limited size of the interlaminar space, ligamentum excision rather than sparing is recommended.

The incidence of recurrent HNP at the same level and side of a previously operated on disc is 2% to 5%.5,55,56 The microscope is especially valuable in this scenario because of the scar between tissue planes, including neural elements. Adequate time must be spent carefully teasing the tissues apart with a blunt instrument (e.g., bipolar, curette, Penfield) before forcefully mobilizing the nerve root. The incidence of complications is understandably higher in revision discectomies.

The classic teaching in cauda equina syndrome is that (1) it is an orthopedic emergency, and (2) a wide decompression through a bilateral approach is necessary. We agree with the first point but not the second. Few disc herniations are too big to be addressed microsurgically. A wider hemilaminectomy may be needed. The microscope is invaluable when working in the severely stenotic canal. If the disc cannot be easily or totally excised unilaterally, then bilateral hemilaminotomies may be done.26,27

The risk for recurrence of HNP after surgical excision is higher in adolescents than in adults. Because of the high proteoglycan content in adolescent discs and the prevalence of disc protrusions rather than disc extrusions, some have recommended percutaneous chemonucleolysis rather than surgical intervention in this age group.25,57,58 Studies have been published with controversial results for surgical discectomy in this patient population.^59–61 Chemonucleolysis may have merit in the treatment of symptomatic disc protrusions, but discectomy is necessary in the setting of an extruded or sequestered disc causing significant or progressive neurologic deficit or pain. These extruded or sequestered fragments are frequently heavily collagenized.^24,62 Long-term follow-up studies of more than 12 years after discectomy in this group have reported good to excellent results in 87% to 92% of patients.^63,64

Dural mobilization (i.e., mobilization of the nervous system, neurodynamic exercise, nerve root gliding, neural tension exercises) should begin as soon as possible in the first week. The preoperative neural compromise and the postoperative inflammation in and around the epidural space contribute to neural broses and dural adhesions. They are occasionally problematic and are easily preventable. An excellent presentation of neural mobilization principles and techniques can be found in Butler.89

Technique.

The therapist should do the following:

• Supine dural mobilization (lower lumbar neural mobilization)—Have the patient lie supine on a firm surface with both knees extended. While the patient holds the back of the thigh with both hands, he or she slowly extends the knee with the ankle dorsiflexed to the point of stretch. He or she then slowly flexes and relaxes the limb. Any symptoms and the maximal amount of knee extension attained should be recorded to monitor progress.

• Prone dural mobilization (upper lumbar neural mobilization)—Have the patient lie prone on a firm surface with both knees extended. Initially the patient may use a pillow under the abdomen for comfort if needed. Have the patient slowly flex the knee to the point of stretch, then slowly extend the knee and relax. Make sure the patient maintains the abdominal brace throughout the exercise to stabilize the lumbar spine. Alternate legs.

Dural mobilization should be done several times a day. The therapist must caution the patient that this exercise may provoke neural symptoms, and that he or she must allow the pain or tingling to resolve to baseline levels before beginning the next repetition. The patient should not overmobilize the neural tissues. As with any exercise, self-mobilization of the nervous system at home is inappropriate until a positive response has been established from repeated movements in the clinic. The dural mobilizations are progressed as tolerated to include other components of the affected nerve (e.g., ankle dorsiflexion, hip internal rotation [IR]). Eventually (in phase III) the patient can perform neural mobilizations while sitting (“sitting slump”).

The early initiation of a progressive spinal-stabilization program is crucial to the eventual tolerance of more strenuous functional activities and sports skills. Because the lumbar spine is inherently unstable around the neutral zone, the trunk musculature must be sufficiently strong and coordinated to stabilize and protect the spine from injury.^90,91 The stabilization program progresses from unloaded spinal positions to partially loaded and eventually fully loaded functional training. The posterior pelvic tilt exercise is the least desirable exercise to obtain active lumbar stability.^90,92–94 The transversus abdominis must be isolated from the remaining abdominal musculature because it has consistently been shown to be active before the other abdominal muscles or the primary movers during limb motions, regardless of direction.^95,96 In addition, the transversus abdominis can become dysfunctional in patients with low back pain.^95,97–100 Therefore the transversus abdominis possesses a superior ability to stabilize the lumbar spine actively and locally.^38,101–103 Although the more superficial abdominal muscles (the obliques) are important in lumbar stability, they are trained later in the program for their rotational contribution to limit lateral shear and torsional stresses and create trunk rotation. Early in phase II, the lumbar multifidi are isolated and trained because of their ability to stabilize segmentally.^102,104,105 In addition, it has been found that the lumbar multifidi atrophy in patients with low back pain and there is a decrease in muscle thickness change with activation.^100,106 Literature has also investigated the importance of the pelvic floor musculature in stabilizing the lumbar spine.^80,107,108 Evidence shows that the pelvic floor muscles cocontract with the transverse abdominus; therefore recruiting the pelvic floor muscles should be considered when instructing in bracing. Bracing has been shown to immediately increase posteroanterior spinal stiffness and stability.¹⁰⁹ Eventually a cocontraction of transversus abdominis, multifidus, and pelvic floor (abdominal bracing) is performed during all exercises and functional activities.^110,111 All the exercises should focus on control and technique and be progressed as tolerated to improve endurance of these primary stabilizers.

The PT should instruct the patient in the neutral spine concept and help the patient find the neutral spine position in various postures. The patient can then be taught to control the transverse abdominus with electromyographic (EMG) biofeedback, pressure biofeedback,^* or rehabilitative ultrasound imaging^{102,112–116} in several positions (e.g., supine, all fours, prone). Feedback available by rehabilitative ultrasound imaging has been shown to improve transverse abdominus and lumbar multifidus muscle recruitment up to 4 months posttraining.^117,118 After that, the patient can progress the postures to include sitting and standing and increase the duration of the contractions to 60 seconds.

Based on the information obtained in the history, the responses to various positions, and the limited clinical testing performed during the initial evaluation, the therapist determines which midrange lumbar movements are tolerated and are indicated for exercise. Correct and controlled lumbar movements are beneficial to the patient after microdiscectomy because hydrostatic changes of the disc promote improved vascularity.^119,120 To this end, the therapist teaches pelvic rocks in pain-free positions (e.g., all fours, prone). A pelvic rock is a repetitive and continuous pelvic tilt from an anterior to a posterior position. A bias toward lumbar extension is typical in the patient who has undergone microdiscectomy because lumbar extension reduces tangential stress posteriorly. A flexion bias is usually not recommended because the surgical entry is into the posterior disc and flexion positions tend to create stress to this area and tension on the incision. A healthy respect for soft tissue healing periods is essential.

The therapist instructs the patient in most of the following exercises in phase I, but he or she should not prescribe any exercise or position for the home program until repeated trials in the clinic have proven painless. Stabilization, flexibility, coordination, and spinal mobility exercises are included in an attempt to address all parameters. The exercise sequence is important and should be considered by the PT when adding exercises. Good technique and control of movement are essential. No exercise should increase the pain pattern or cause lingering pain. Clearly some muscular soreness may accompany the program, but this should be well tolerated and transient. The typical patient should be able to contract the transversus abdominis for 60 seconds in various positions within approximately 1 week after the initial visit.

The following exercises are taught in phase I:

1 Abdominal bracing on all fours (i.e., isolated transverse abdominis contraction, lumbar multifidus, and pelvic floor cocontraction) progressed to quadruped abdominal bracing with alternate arm raises

2 Quadruped pelvic rocks (i.e., midrange lumbar active range of motion [AROM])

3 Supine dural stretching (or prone dural stretching for upper lumbar disorders)

4 Supine abdominal bracing (isolated transverse abdominis contraction, lumbar multifidus, and pelvic floor cocontraction)

5 Supine pelvic rocks (i.e., midrange lumbar flexion AROM)

6 Supine abdominal bracing with arms behind head progressed to abdominal bracing with alternating arm raises

7 Supine gluteal, hip external rotator, and hamstring stretches to correct myofascial limitations; actively holding neutral spine during these low-load, long-hold exercises is important (Fig. 15-10)

8 Side-lying pelvic rocks (i.e., midrange lumbar lateral flexion AROM)

9 Prone pelvic rocks (i.e., midrange lumbar extension AROM)

10 Prone abdominal bracing with alternate arm raises progressed to prone abdominal bracing with bilateral arm raises

11 Gastrocnemius and soleus stretching in standing position (Fig. 15-11)

12 Partial squats to 60° of knee flexion while maintaining neutral spine with abdominal bracing

Spinal mobilization of the lumbar spine is rarely used in phase I or II. Mobilization of the hips or thoracic spine may be needed and is best addressed on an individual basis. When progress is poor with active movements and deemed secondary to a hypomobile segment, mobilization to restore lumbar movement may be necessary in phase II. In phase III, mobilization can play an important role and is used frequently to reduce pain during specific lumbar motions, especially at end of range. A review of Maitland,121 Mulligan,¹²² and Paris⁵⁶ may assist in clinical reasoning.

Cardiovascular conditioning is an important part of the rehabilitation program and is beneficial both for patients recovering from lumbar microdiscectomy and those with chronic low back pain.123 In addition, endurance training of the LE musculature improves tolerance to prolonged standing and walking. When LE muscles fatigue, poor body mechanics soon follow. The patient typically performs aerobic training by progressive walking (on a treadmill or outdoors without hills), stationary cycling (on recumbent or upright bikes with the patient paying close attention to the maintenance of lordosis and avoidance of hip sway), or swimming (initially only the freestyle stroke with avoidance of “craning” during the breathing phase). Craning is suboccipital extension with rotation (occipitoatlantal to atlantoaxial) or cervical extension with rotation (C2 to C7). Swimming and aqua therapy are usually delayed until the second or third week after surgery to ensure complete wound healing and sufficient lumbar stabilization. The PT must caution patients never to jump or dive into the water, but rather use the ladder or steps. Aquatic therapy for postoperative lumbar rehabilitation is not covered in this chapter, but Watkins , Williams, and Watkins¹²⁴ present a good source for the interested clinician.

The therapist determines the patient’s training heart rate and adheres to this guideline during all conditioning exercises. Patients who have no prior history of aerobic exercise or who are very deconditioned must progress slowly and be carefully monitored. Aerobic conditioning in phase I (with focus on correct postures and mechanics) may include walking, stationary cycling, and water exercises. Patients should avoid stair climbers and cross-country skiing machines until phase II, when adequate trunk stability is usually attained. In addition, rowing, running, and in-line skating should be avoided until phase III, when significant active lumbar stability has been achieved.

The progression of cardiovascular training is highly variable and depends on the patient’s prior level of conditioning and present goals. He or she can usually begin with 5- to 10-minute bouts and progress at 5-minute intervals up to 30 or 60 minutes. The therapist must pay careful attention to patient position because correct postures deteriorate as fatigue increases. Neurologic weakness of the hip flexors or abductors, quadriceps, hamstrings, ankle dorsiflexors, and plantar flexors significantly alters gait and requires modification of the aerobic program to avoid abnormal mechanical stress.

Along with the patient’s history, the inspection of the incision site during the initial evaluation helps determine whether extra measures are needed. Any signs of infection are a red flag that requires prompt medical intervention. Some patients desire “invisible” scars, whereas others are much less concerned. Because patients scar differently, the therapist should monitor their progress and offer solutions to excessive scarring or scar stretching. A compression taping technique can be used to limit hypertrophic scar formation and reduce surgical scar widening. First, the therapist folds a 10- × 6-cm Neoprene pad in half and secures it with a 2-inch wide elastic tape (Elastikon tape)* (Fig. 15-12). The pad is then affixed horizontally over the closed wound (Figs. 15-13 and 15-14) to provide both compression and approximation of the surgical scar. The patient wears the compression patch constantly for 6 to 10 weeks, removing it only to bathe. It should not be applied until the wound site is completely healed (approximately 2 weeks).

A recent Cochrane systematic review of randomized controlled trials concluded that high-intensity exercise programs initiated 4 to 6 weeks postmicrodiscectomy lead to decreases in pain and disability faster than no treatment or low-intensity programs.125 However, although early exercise intervention resulted in faster decreases in pain and disability, clinical outcomes at 1-year follow-up had similar results versus low-intensity or no exercise.^126,127 The therapist should instruct the patient in the correct way to contract and control the lumbar multifidus with EMG biofeedback. Special attention to the training of this important segmental stabilizer is essential.¹²⁸ Retraction of the paraspinal muscles during surgery can denervate the multifidus muscle.¹²⁹ Fortunately, lumbar microdiscectomy requires a minimal wound opening, so this complication is lessened. The patient should perform abdominal bracing (holding neutral spine with a cocontraction of the transverse abdominis, multifidus, and pelvic floor) in supine, prone, and all-fours positions, progressing to transition movements. Ultimately, the cocontraction is used to stabilize the lumbar spine during all ADLs. The therapist can progress the patient’s midrange lumbar movements and spinal-stabilization program as tolerated, using Swiss ball exercises to improve balance and dynamic lumbar stabilization during sitting. The patient should continue to avoid axial loading during end-range lumbar flexion or lateral flexion movements. As the patient shows control and tolerance, the exercise level may be increased. Pain during exercise typically requires correction of the technique or exercise modification. In addition, muscle groups that may have been weakened by neurologic compromise (e.g., hip abductors, quadriceps, ankle plantar flexors, dorsiflexors) must be strengthened. The slow twitch fibers are most involved and are easily fatigued. The longer that neural compression and inflammation have been present, the longer the period before regeneration occurs. Careful attention to back-protected positions during strengthening exercises is crucial to avoiding reinjury.

Typical Phase II Exercises.

The therapist should do the following:

1 Supine abdominal bracing with alternate SLRs, progressed to abdominal bracing with unsupported LE extension (i.e., cycling), progressed to abdominal bracing with unsupported upper extremity (UE) and LE extension (i.e., dying bug) (Fig. 15-15)

2 Supine dural mobilization, progressed to incorporate a belt or towel around the foot to enhance the effect

3 Supine partial sit-ups, progressed to partial sit-ups with rotation to facilitate oblique strengthening (Fig. 15-16)

4 Double-leg bridging, progressed to single-leg bridging and then to single-leg bridging with opposite knee extended (Fig. 15-17)

5 Prone elbow lying, progressed to partial press-ups

6 Prone abdominal bracing with single-leg raises, progressed to prone double-leg raises

7 Standing repetitive squats to 60°, progressed to 90° for 2 to 3 minutes

8 Abdominal bracing on all fours with single-leg raise, progressed to opposite arm and leg raises (Fig. 15-18)

9 Balance board training on both limbs, progressed in duration

10 Isolated strengthening of neurologically compromised muscles

11 Swiss ball sitting exercise progression (in neutral spine with abdominal brace)

12 Stretching of the quadriceps, gluteals, hip external rotators, iliopsoas, hamstrings, and calves as required to correct myofascial limitations (Figs. 15-19 through 15-22; see also Fig. 15-11)

Scarring of myofascial elements with collagen cross-fibers or fibrofatty tissue limits muscle broadening during contraction and connective tissue elasticity during movement.130 Muscle spasm and protective guarding of the gluteals and low back musculature may persist. Soft tissue mobilization of the lumbar paraspinals and buttock musculature is frequently needed to improve muscle function and reduce spasm.¹³¹ The PT must exercise care when performing soft tissue mobilization to the paraspinals before the third or fourth week after surgery because the tissue healing is incomplete. The mechanical and reflexive effects of soft tissue mobilization are well suited for patients recovering from microdiscectomy, and certain techniques are particularly beneficial before paraspinal strengthening (e.g., side-lying paraspinal pull from midline). Careful questioning and soft tissue examination will uncover gluteal trigger points that can cause buttock or LE pain patterns.⁷⁶ These myofascial pain syndromes are not uncommon preoperatively and may linger postoperatively. With appropriate treatment they can be relieved so that the functional restoration program may progress. Scar massage to release adherent soft tissue also may be needed.

Functional training exercises (i.e., sports-specific drills, work-hardening activities) typically begin in phase III. Preset goals determine the kinetic activities that are to be the focus of rehabilitation. The therapist closely supervises the progression of these activities, paying careful attention to the quality of spinal mechanics and lumbar stabilization. Functional training is focused on trunk movements that simulate activities to which the patient will return. Sports-specific training (Figs. 15-23 through 15-26) can begin if the patient has achieved sufficient active lumbar stability and spinal mobility in fully loaded positions, as well as adequate myofascial flexibility and conditioning. The therapist can use proprioceptive training with balance boards and Swiss balls. Initially, athletes who take part in running and jumping activities are most safely trained with unloading devices,^* during supervised treadmill running or jump training. These patients are typically well conditioned before surgery and have progressed postoperatively without setbacks.

Golfers need to be trained to hold the neutral spine dynamically during all five phases of the swing. The PT can incorporate specific strength, flexibility, and balance exercises to achieve a safe and mechanically sound golf swing.¹²⁴

Work-hardening activities for medium to heavy work classifications typically begin at 8 weeks and include lift training from 25 to 50 lb. Workers in these fields need special attention with regard to materials handling and should have a functional capacity evaluation 10 to 12 weeks after surgery to determine appropriate return-to-work status.

The exercise program progresses in intensity and difficulty to include rotational trunk stability, overhead activities, and balance training using a balance board. Training the patient in diagonal patterns in loaded positions better simulates real-life situations. A new stabilization exercise for patients in phase III challenges the obliques and transverse abdominals with minimal stress to passive tissues.⁷⁶ McGill¹³³ refers to this exercise as isometric side-support on knees or on feet (depending on the degree of difficulty). Therapists should prescribe this exercise for home performance only after proving patient tolerance during clinic sessions.

The spinal mobility program attempts to restore painless and full lumbosacral ROM. The PT should prescribe appropriate exercises and incorporate mobilization to achieve full and pain-free lumbar ROM and continue the stretching exercises needed to attain normal myofascial flexibility.

Spinal mobilization should be used when necessary to restore motion at hypomobile segments and reduce pain associated with movement. Because the restoration of normal spinal motion is a primary goal, the therapist must identify and correct aberrant arthrokinematics. The expanded mechanical testing in phase III will reveal limitations or provoke symptoms that require attention. Maitland,121 Mulligan,¹²² and Paris⁵⁶ can be reviewed to assist in clinical reasoning.

Patients should not start a running program until after the twelfth week postoperatively because of the high compressive and repetitive axial loads at heel strike. A walk-run program should be initially implemented on a treadmill, with the therapist supervising and analyzing gait. When the patient does resume running, it should be in the morning hours when the disc is maximally hydrated.124

The comprehensive lumbar evaluation performed in phase III reveals any limitations in motion, weaknesses, neural restrictions, and painful movements that still need to be addressed. The PT can obtain additional information from computerized testing devices132^* that provide objective data on lumbar motion speed, acceleration and deceleration, and degree of ROM. Other testing equipment, such as computerized isokinetic machines, determines objective trunk strength values at various speeds of lumbar ROM. This information can be helpful in guiding the therapist to choose appropriate exercises to remedy any weaknesses or limitations, especially in more physically active patients.

Most patients recovering from lumbar microdiscectomy progress uneventfully if properly educated and carefully rehabilitated. The PT can facilitate the systematic training program to achieve a safe and rapid return of function by applying clinical knowledge and manual skills.