Mechanical Load of the Lumbar Spine During Forward Bending Motion of the Trunk–A Biomechanical Study

Abstract

We found that the increase of the actual spinal load during trunk flexion in healthy individuals consisted of the theoretical spinal load and load generated by the back muscle activities.

The effect of increasing resistance on trunk muscle activity during extension and flexion exercises on training devices

“…The findings of trunk electromyographic (EMG) amplitudes during the flexion and extension movements used daily in standing positions have been reported in a healthy population (Bankoff et al, 2000;Dickey et al, 2003;Gupta, 2001;Kaigle et al, 1998;Kuriyama and Ito, 2005;Larivière et al, 2000;Leinonen et al, 2000;Mathieu and Fortin, 2000;Marras and Mirka, 1992;Mirka et al, 1997;Neblett et al, 2003;Olson et al, 2004;Olson et al, 2006;Paquet et al, 1994;Shirado et al, 1995;Takahashi et al, 2006;Wolf et al, 1979). Extensive research was also performed on muscle fatigability (Kankaanpää et al, 2005;Kankaanpää et al, 1997;Lee et al, 1996;Roy et al, 1989;Sparto et al, 1999;Van Dieën et al, 2003) and muscle activation during different lifting movements (Arjmand and Shirazi-Adl, 2005;Bonato et al, 2003;Cresswell and Thorstensson, 1994;Gagnon et al, 2001;Granata and Marras, 1995;Kingma et al, 2004;Lee and Lee, 2002;Noe et al, 1992;Potvin et al, 1991;Roy et al, 1998;Takahashi et al, 2006). In training exercises, muscle function was analyzed in a standing position using loads in the hands (Arjmand and Shirazi-Adl, 2006;Peach et al, 1998) and resistance from a device …”

Development and Validation of a Musculoskeletal Model of the Fully Articulated Thoracolumbar Spine and Rib Cage

“…Although the correction factor has only been computed for lumbar intervertebral disks, we also used this same correction factor to estimate IDP in the thoracic spine, because no study that we are aware of has determined a thoracic-specific correction factor. CSA Vert was measured in three of the studies reporting lumbar IDP [47,49,50], and a value of 18 cm 2 , reported by Wilke et al [50], was used for the lumbar IDP studies that did not measure CSA Vert [45,48]. For thoracic levels, we measured CSA Vert in our own CT scans of subjects that closely matched the study participants in sex, age, height, and weight.…”

“…To evaluate the accuracy of vertebral loading and muscle force predictions from the model, we simulated a variety of activities for which prior studies have acquired in vivo measures of IDP, vertebral implant loads, or myoelectric activity of trunk muscles. A list of these validation studies with the activities they investigated, the characteristics of the study participants, and the primary measurements made is found in Table 3 [45][46][47][48][49][50][51]. For each validation study we created a version of our spine model that was scaled to the average height and weight of the study participants, and we estimated muscle group CSA and AP and ML moment arms from previously published regressions [42] using the average age, sex, height, and weight of the study participants.…”

Porous Biodegradable Lumbar Interbody Fusion Cage Design and Fabrication Using Integrated Global-Local Topology Optimization With Laser Sintering

“…To estimate in vivo load level in different postures, intradiskal pressure was measured in flexion up to 30 deg using a pressure needle, and converted to load by multiplying disk area, which was measured from a magnetic resonance imaging scan [35]. In that study, load levels at L4-L5 lumbar spine have been estimated around 500 N to 3000 N, varying according to posture.…”