Movement amplitude on the Functional Re-adaptive Exercise Device: deep spinal muscle activity and movement control

Abstract

PurposeLumbar multifidus (LM) and transversus abdominis (TrA) show altered motor control, and LM is atrophied, in people with low-back pain (LBP). The Functional Re-adaptive Exercise Device (FRED) involves cyclical lower-limb movement against minimal resistance in an upright posture. It has been shown to recruit LM and TrA automatically, and may have potential as an intervention for non-specific LBP. However, no studies have yet investigated the effects of changes in FRED movement amplitude on the activity of these muscles. This study aimed to assess the effects of different FRED movement amplitudes on LM and TrA muscle thickness and movement variability, to inform an evidence-based exercise prescription.MethodsLumbar multifidus and TrA thickness of eight healthy male volunteers were examined using ultrasound imaging during FRED exercise, normalised to rest at four different movement amplitudes. Movement variability was also measured. Magnitude-based inferences were used to compare each amplitude.ResultsExercise at all amplitudes recruited LM and TrA more than rest, with thickness increases of approximately 5 and 1 mm, respectively. Larger amplitudes also caused increased TrA thickness, LM and TrA muscle thickness variability and movement variability. The data suggests that all amplitudes are useful for recruiting LM and TrA.ConclusionsA progressive training protocol should start in the smallest amplitude, increasing the setting once participants can maintain a consistent movement speed, to continue to challenge the motor control system.Electronic supplementary materialThe online version of this article (doi:10.1007/s00421-017-3648-3) contains supplementary material, which is available to authorized users.

Countermeasure Development for Lumbopelvic Deconditioning in Space

“…Therefore, the automatic recruitment of TrA and LM during FRED exercise would appear to offer an advantage over current practice. Increasing crank amplitude was observed to increase movement variability, the range of TrA and LM thickness peaks, as well as mean TrA muscle thickness [63]. These outcomes are all measures of motor control of either global movement or muscle recruitment.…”

“…low back pain, astronauts). Winnard et al [63] compared the thickness of LM and TrA at a range of movement amplitudes in an asymptomatic sample. A large body of evidence has linked dysfunction and/or atrophy of TrA and LM to lumbopelvic deconditioning and LBP [3,4,9,11,12].…”

“…It is hypothesised that correct exercise on FRED results in reduced front foot loading. FRED provides visual feedback that encourages users to exercise at a constant, controlled speed and frequency ratio, which is hypothetically the most energy efficient movement [63]. Additional feedback encourages users to maintain even movements throughout the exercise, training control of the lumbopelvic area and lower limbs during dynamic functional movements.…”

Effects of a six-week exercise intervention on function, pain and lumbar multifidus muscle cross-sectional area in chronic low back pain: A proof-of-concept study

“…Participants were coached to ensure they did not exercise beyond their individual point of tiring and to ensure good exercise technique as determined by low variability of (footplate movement) speed throughout each cycle of movement. They all started at the smallest amplitude (0.2m) and were progressed to a larger FRED amplitude setting to increase demand (Winnard, Debuse, Wilkinson, Samson, et al, 2017) once they achieved a 30% improvement in movement variability from their baseline, and based on their clinical presentation (e.g. fatigue, leg discomfort).…”

Direct Segmented Sonification of Characteristic Features of the Data Domain

“…We applied the above DSSon method to biomechanical signal data taken from the Functional Readaptive Exercise Device (FRED), an exercise machine designed for use in physiotherapy to help patients with low back pain [12]. The current version of FRED is a modified cross-trainer but which offers minimal resistance ( Fig.…”