The Effect of Sacroiliac Joint Pain on Muscle Recruitment

Research Review: Altered Lumbopelvic Hip Muscle Recruitment in Individuals with Sacroiliac Joint Pain

By Stefanie DiCarrado DPT, PT, NASM CPT & CES

Edited by Brent Brookbush DPT, PT, MS, PES, CES, CSCS, ACSM H/FS

Original Citation: Hungerford, B., Gilleard, W., Hodges, P. (2003) Evidence of altered lumbopelvic muscle recruitment in the presence of sacroiliac joint pain. Spine 28(14), 1593-1600 - ARTICLE

Caption: Note the common tendon shared by the semitendinosus and biceps femoris proximally, and the fascial continuity with the sacrotuberous ligament

The Sacroiliac Joint (SIJ) is the connection between the vertebral column and the lower extremity.

Why is this relevant?: This study provides information related to altered core muscle activation during lower extremity movements patterns in individuals with Sacroiliac Joint Pain (SIJP) and compares those findings to those without pain. The information in this study may highlight certain muscles or motor patterns that should be considered during intervention for Sacroiliac Joint Dysfunction (SIJD) , and adds to our understanding of motor control of the Lumbo Pelvic Hip Complex (LPHCD) .

Study Summary

Load transference through the pelvis

Review & Commentary: Despite a relatively small sample size, this study provides strong evidence of altered lumbopelvic muscle recruitment in those with SIJP. Authors analyzed not only SIJP vs no SIJP but compared muscle onset activity in symptomatic and asymptomatic sides of an individual with SIJP.

Researchers maintained a standardization of assessment by having the same physiotherapist perform all evaluations. They narrowed their population to only those with unilateral SIJP who did not report additional lumbar pain. All SIJP group members tested positive for the following: pain with vertical loading of the symptomatic side; ASLR (positive if the pain reported during a supine straight leg raise); Stork Test (positive if anterior innominate rotation occurs with standing hip flexion). Researchers excluded potential control subjects having no palpable motion between the posterior superior iliac spine (PSIS) and sacral segment S2 as this is indicative of impaired pelvic function.

Authors used surface electrodes to obtain EMG data and described placement in sufficient detail for replication of the study. They note cross talk as a risk for surface EMG but explain the psoas major was unlikely to interfere with IO  readings as it lies very deep to that area; however, they mention that signals from the transverse abdominis (TVA) may confound IO  readings. Signals from the TVA did not concern the authors however, since the goal was to analyze the onset of "transversely oriented abdominal muscles" and therefore differentiating between IO  and TVA  was not necessary for the purposes of this study (1594).

Subjects in both groups practiced standing hip flexion to 90 degrees prior to EMG analysis to ensure proper execution without self-limiting pain. Researchers collected data from the stance leg during five trials performed with both the left and with the right leg (for a total of 10 trials). Subjects stood in a relaxed posture between each trial. A force platform provided information on movement initiation noting when the subject's body mass shifted toward the stance leg. Interestingly, the initial weight shift was toward the leg to be flexed and then a second shift occurred to the stance leg. The authors did not mention if this pattern differed between the two groups but instead used this information as a baseline to determine if muscle activation occurred before or after initiation of movement.

A reactive response to movement was defined as muscle activation occurring greater than 20ms after initiation of movement. The authors explained this is due to nerve conduction speed and synaptic transmission. In other words, the time it takes for a signal to travel from the brain to the muscle once initial movement is detected. This means that any muscle EMG activity prior to or within 20ms is an anticipatory reaction or a preemptive "setting" of muscles to prepare for the upcoming limb motion.

Why is this study important?

This study provides EMG evidence of the effect of Sacroiliac Joint Dysfunction (SIJD) and the resulting SIJP can negatively impact the onset timing of stabilizing muscles such as the IO , LM , and GMax  during single leg stance. Further, it supports previous research (see Decreased Recruitment of Transverse Abdominis in Individuals with Low Back Pain ) that demonstrated a delayed firing of the TVA , IO , and LM  during upper extremity motion.

The IO , LM , and GMax  provide compressive forces through the SIJ to assist in stabilization and load transfer from the upper extremity (UE) down and LE up. Temporal changes in the recruitment of these muscles can cause pelvic instability and perpetuate existing dysfunction or lead to further dysfunction up or down the kinetic chain. The symptomatic and asymptomatic sides in individuals with SIJP demonstrate latent firing of the IO  and LM , indicating a lack of anticipatory stabilization. It is interesting to note that the GMax  was only delayed on the symptomatic side in those with SIJP. The increase in BF  activity, is likely synergistic dominance related to the latent firing of the GMax  - as the glute max plays a role in sacroiliac joint compression  and stabilization , the increased activity of the BF  may be a compensatory means of stabilizing the sacrum via the sacrotuberous ligament and/or may be a compensation for the loss of force production during hip extension. Synergistic dominance is further explained in the predictive models of SIJD and Lumbopelvic Hip Complex Dysfunction (LPHCD) .

How does it affect practice?

Pelvic stability during single leg stance is imperative during walking, running, climbing stairs, sports activities, and other functional tasks; therefore, optimal stabilization and muscle recruitment is integral in all populations. Activation exercises for the IO , LM , and GMax (and TVA ) along with carefully considered subsystem integration  (most likely Posterior Oblique Subsystem  followed by Anterior Oblique Subsystem ) are an integral parts of an integrated corrective program to address SIJD  and LPHCD . The SIJD Corrective Exercise  article contains a sample routine and a deeper breakdown of this specific condition.

Arthokinematics of the SIJ, described in the predictive model of SIJD  is controversial but requires attention. In certain cases of SIJD , joint dyskinesis must be fixed before addressing muscle imbalances and should be performed by a licensed professional (Physical Therapist or Chiropractor).

How does it relate to Brookbush Institute Content?

As mentioned in Decreased Recruitment of Transverse Abdominis in Individuals with Low Back Pain , verbal and manual cues to “Draw-in” during all activities, along with isolated activation techniques of the GMax  and TVA  (note that the LM  and IO  tend to activate simultaneously with the TVA ) when an individual exhibits signs of dysfunction, are consistently used in the Brookbush Institute during rehabilitation, fitness and performance enhancement programs. The spinal and pelvic stabilization provided by the TVA , LM , and GMax  is recognized throughout the predictive models of LPHCD and SIJD .

The Brookbush Institute considers SIJD  to be a dysfunction within a dysfunction, as SIJD  can be viewed as a segment of LPHCD. Essentially, one can consider SIJD  an asymmetrical LPHCD  as exercises to address both dysfunctions are the same, but implementation may vary depending on the side of SIJD . The predictive model of SIJD  presented by the Brookbush Institute can be tricky to understand and so it is recommended that those new to the field of corrective exercise first fully understand the LPHCD  model before attempting to correct a suspected SIJD  alone.

The following videos emphasize proper technique to activate not only the TVA  and GMax separately, but integrate TVA activation with GMax  activation. These techniques should recruit the muscles indicated as well as the LM  and IO to assist in pelvic stabilization.

TVA Isolated Activation

Gluteus Maximus Isolated Activation

TVA and Gluteus Maximus Activation and Progressions

Glute Activation Circuit

© 2014 Brent Brookbush

Questions, comments, and criticisms are welcomed and encouraged -