CURRENT PRINCIPLES AND INTERVENTION STRATEGIES FOR HLD REHABILITATION Rehabilitation interventions for the HLD are diverse and varied. In developing this phased protocol, the authors attempted to merge current clinical practices with available research in providing suggestion for future clinical practice. Although the focus
of the protocol described in this commentary is a progressive exercise intervention, there are numerous clinical practices which are important to discuss in the context of providing a supportive environment in the management of an HLD. These clinical practices include: manual therapy, addressing the Janda Pelvic Crossed Syndrome, gluteal weakness, pelvic floor and diaphragm relationship, transversus abdominis/multifidi recruitment, latissimus dorsi and thoracolumbar fascia, and stretching.
Manual Therapy The role of manual therapy, including mobilization, manipulation, and soft tissue interventions including trigger point therapy in the management of a HLD is beyond the scope of this article. Although caution regarding rotatory lumbar manipulation is advised,66 manipulation has demonstrated greater improvement in pain and functional outcomes over sham treatment in treatment of patients with lumbar HLD.67 In addition, skilled manual therapists have noted that, in their experience, appropriately utilized mobilization and manipulation above and below the involved spinal segment including addressing the pelvis, or even addressing restrictions in the lower extremity, may decrease the amount of mechanical stress placed on the HLD. Boal and Gillette68 studied this clinical practice and demonstrated that stabilization training alone was found to be less effective than when accompanied by a course of manual therapy. Beyond mobilization and manipulation, myofascial trigger point and soft tissue restrictions are common in chronic LBP patients69 and can even mimic HLD symptoms,70 therefore addressing them with manual therapy may be important. Manual therapy can play an integral role in pain management and potentially provide an optimal environment for the disc to heal, in particular during early and middle stages of rehabilitation. However, as the patient progresses into later stages of rehabilitation, it is probably beneficial to deemphasize the role of manual therapy and maximize patient active contributions to rehabilitation and independence with management.
Janda Pelvic Crossed Syndrome, gluteal weakness, and the pelvic ๏ฌ oor and diaphragm relationship It is difficult to speak of the active and neural control subsystem of the Panjabi spinal stability model with out touching on the concepts of neuromuscular control and length tension relationships as introduced by Vladimir Janda. The classic pelvic crossed syndrome is a described imbalance between tight and short hip flexors and lumbar erectors spinae and weak or inhibited gluteal and abdominal muscles.71 Evidence for decreased hip flexor extensibility is evident in individuals with a history of LBP.72 However, research results are varied regarding gluteus maximus, hamstring, and erector spinae activation order.73-
77 Further yet, the practice of promoting earlier gluteus maximus activation in LBP conditions as a protective mechanism is in question, as the gluteus maximus already appears to activate earlier in individuals who experience LBP than in those who are asymptomatic both during gait78 and with movement into hip extension from flexion.79 Although the role of the gluteus maximus and hip extension in the HLD and LBP population is unknown at this time, decreased hip abduction and external rotation strength, have been implicated as a predictors of back and lower extremity injury.80,81 Even though research evidence is lacking regarding the full implications of the pelvic crossed syndrome, clinical experience demonstrates significant value in identifying and addressing gluteal weakness and alterations in hip flexor length in patients in the LBP and the HLD population.
Beyond the possible role of the gluteals on the spine, interest is growing regarding the association between the pelvic floor, the diaphragm, and spinal stability. Arab et al utilized ultrasound imaging as a method of examining pelvic floor dysfunction (PFD) and found the incidence of PFD greater in their LBP group than in comparison to the asymptomatic group.82 A series of case studies have also shown an association between aberrant motor strategies in the pelvic floor and diaphragm and sacroiliac joint pain,83 providing a theoretical explanation for spinal instability due to dysfunction that exists in the pelvis. Research regarding the addition of a pelvic floor contraction to the abdominal activation techniques is conflicting. Previous research has demonstrated that the addition of a pelvic floor contraction increased transversus abdominis (TA) increased thickness as demonstrated by ultrasound imaging,84 however, it does not appear that voluntary pelvic floor contraction results in significantly increased abdominal
wall musculature EMG activity.85 The diaphragm has also been theorized to play a role in spinal stability.86 The authors encourage clinical exploration in area of pelvic floor and diaphragm training during the early phases of a rehabilitation program and have included a pelvic floor assisted exercise in our prescriptive suggestions.