The effects of rehabilitation on the muscles of the trunk following prolonged bed rest

Abstract

Microgravity and inactivity due to prolonged bed rest have been shown to result in atrophy of spinal extensor muscles such as the multifidus, and either no atrophy or hypertrophy of flexor muscles such as the abdominal group and psoas muscle. These effects are long-lasting after bed rest and the potential effects of rehabilitation are unknown. This two-group intervention study aimed to investigate the effects of two rehabilitation programs on the recovery of lumbo-pelvic musculature following prolonged bed rest. 24 subjects underwent 60 days of head down tilt bed rest as part of the 2nd Berlin BedRest Study (BBR2-2). After bed rest, they underwent one of two exercise programs, trunk flexor and general strength (TFS) training or specific motor control (SMC) training. Magnetic resonance imaging of the lumbo-pelvic region was conducted at the start and end of bed rest and during the recovery period (14 and 90 days after re-ambulation). Cross-sectional areas (CSAs) of the multifidus, psoas, lumbar erector spinae and quadratus lumborum muscles were measured from L1 to L5. Morphological changes including disc volume, spinal length, lordosis angle and disc height were also measured. Both exercise programs restored the multifidus muscle to pre-bed-rest size, but further increases in psoas muscle size were seen in the TFS group up to 14 days after bed rest. There was no significant difference in the number of low back pain reports for the two rehabilitation groups (p=.59). The TFS program resulted in greater decreases in disc volume and anterior disc height. The SMC training program may be preferable to TFS training after bed rest as it restored the CSA of the multifidus muscle without generating potentially harmful compressive forces through the spine.

Muscle Control and Non-specific Chronic Low Back Pain

“…Prolonged bed rest in the absence of back pain can also lead to atrophy of the MF seen on imaging 80 and the atrophy can be reversed with appropriate exercises 81. There appears to be no relationship between MF function and amount of fat infiltration 82.…”

Disc herniations in astronauts: What causes them, and what does it tell us about herniation on earth?

“…It has been established that muscle atrophy occurs around the lumbar spine during spaceflight [31]. Data from bed rest on Earth suggest that the time course of lumbar muscle size recovery [14,16,32,33] and the recovery of lumbar extension torque [16] is within ''weeks'' after bed rest. However, muscle function, as measured by superficial electromyography recordings [34,35], may take ''months'' to recover.…”

The immediate effects of exercise using the Functional Re-adaptive Exercise Device on lumbopelvic kinematics in people with and without low back pain

“…FRED exercise may, therefore, be beneficial for the rehabilitation of people with LBP, and the prevention of LBP. The latter is particularly in view of evidence that shows that lordosis decreases in low-activity populations which suffer disuse atrophy of LM and TrA resulting in increased risk of spinal injury and pain (Buckey 2006;Hides et al 2011;Sayson and Hargens 2008). The capacity of FRED exercise to automatically promote increased lordosis, therefore, suggests it may be a useful intervention for both training LM and TrA as part of a rehabilitation programmes for LBP and for improving lubopelvic position, including recovery of lumbar lordosis.…”

“…Altered spinal mechanics and LBP have been linked with atrophy (Hides et al, 2008a;Danneels et al, 2000;Hodges et al, 2006;Hodges & Richardson, 1996;Ferriera et al, 2004) and altered motor control (Hodges & Richardson, 1996) of the lumbar multifidus (LM) and transversus abdominis (TrA) muscles. Atrophy of LM and TrA has also been associated with loss of lordosis, development of back pain and spinal injury, and following periods of low activity and disuse of spinal muscles (Buckey, 2006;Hides et al, 2011;Sayson & Hargens, 2008).…”

“…However, the immediate effect of FRED exercise on lumbopelvic kinematics in asymptomatic people or those with LBP has not yet been investigated. As loss of lordosis has been linked to LM and TrA atrophy (Buckey, 2006;Hides et al, 2011;Sayson & Hargens, 2008), this study aimed to determine the immediate effect of FRED exercise on lumbopelvic kinematics in the sagittal plane in people with and without LBP.…”