The Effects of Short Arc Banding: A Novel Exercise Intervention in Patients With Chronic Low Back Pain

Multifidus muscle is well known and documented to be a segmental spinal stabilizer and postural muscle. (Bajek, Bogduk) Previous studies have shown evidence that patients with low back pain (LBP) present with multifidus muscle atrophy. It has been documented that patients presenting with unilateral back pain demonstrate an ipsilateral state of reduced cross sectional area of lumbar multifidus (LM) at the segmental level of injury or pain.(Barker, Hides) Chronic LBP sufferers demonstrate a localized and segmentally specific decrease in cross sectional area of multifidus.(Hides) It has been theorized that multifidus muscle surrounding a chronically painful or degenerative segment is less able to stabilize the spine at that segment, predisposing chronic LBP patients to exacerbation due to the inability to cope with demands of day to day life. (Bajek)

Rehabilitative Ultrasound Imaging (RUSI) has been verified as accurate and reliable in determining cross sectional area of lumbar multifidus (Hides). The interrater and intrarater reliability of RUSI has been shown high utilizing a standardized protocol. (Hides) Measurement of LM contraction using RUSI has been shown a valid and useful measure to determine activation of LM as correlated with EMG. (Kiesel) RUSI has been correlated with MRI which is the gold standard for measuring CSA of LM. (Hides)

Type I muscle fibers are the predominant muscle fiber type in lumbar multifidus which has led researchers to pursue spinal stabilization exercises which focus on isometric contractions. These interventions stimulate mainly Type I muscle fibers because they do not use speed or loading parameters theorized necessary to stimulate Type II fibers. (Rissanen, Ng) Previous studies by Rantanen examined LM fiber type in post surgery low backs. Patients with good recovery (minimal to no symptoms 5 years after surgery) showed increased Type II muscle fiber type in relation to those with a poor recovery and Type I fibers increased. (Rantanen) Limited mobility might account for decrease in diameter in Type II fibers in patients undergoing lumbar surgeries.

Notably, Type I muscle fibers appear to increase in size in the presence of chronic LBP. This is probably due to chronic pain induced low tension muscle spasm. (Mattila, Rantanen) Stokes suggested that LM takes on an increasing role in spinal stability due to atrophy of other muscles, thus the increase in size of Type I fibers versus Type II.

To date, the effects of a short arc fast tapping exercise with band resistance or short arc banding (SAB) on the cross sectional area of multifidus has not been documented in the literature. Short arc banding is a novel exercise treatment and to our knowledge is the first study of this mode of exercise. Using a fast motion against band resistance we hope to reach threshold necessary to stimulate not only type I muscle fibers which predominate the LM, but also type II muscle fibers. From the literature, type II muscle fibers decrease in cross sectional area in the presence of a segmental spinal lesion such as lumbar disc herniation. Type II muscle fibers of multifidus aid the spine to respond to and stabilize a ballistic load. Since modern man is much more sedentary, lumbar spines are not loaded adequately to produce stimulation and maintain size of Type II muscle fibers