Altered preparatory pelvic control during the sit-to-stance-to-sit movement in people with non-specific low back pain

Hip biomechanics in patients with low back pain, what do we know? A systematic review

BACKGROUND

Biomechanical alterations in patients with low back pain (LBP), as reduced range of motion or strength, do not appear to be exclusively related to the trunk. Thus, studies have investigated biomechanical changes in the hip, due to the proximity of this joint to the low back region. However, the relationship between hip biomechanical changes in patients with LBP is still controversial and needs to be summarized. Therefore, the aim of this study was to systematically review observational studies that used biomechanical assessments in patients with non-specific LBP.

METHODS

The search for observational studies that evaluated hip biomechanical variables (i.e., range of motion, kinematic, strength, and electromyography) in adults with non-specific acute, subacute, and chronic LBP was performed in the PubMed, Embase, Cinahl and Sportdiscus databases on February 22nd, 2024. Four blocks of descriptors were used: 1) type of study, 2) LBP, 3) hip and 4) biomechanical assessment. Two independent assessors selected eligible studies and extracted the following data: author, year of publication, country, study objective, participant characteristics, outcomes, and results. The methodological quality of the studies was assessed using the Epidemiological Appraisal Instrument and classified as low, moderate, and high. Due to the heterogeneity of the biomechanical assessment and, consequently, of the results among eligible studies, a descriptive analysis was performed.

RESULTS

The search strategy returned 338 articles of which 54 were included: nine articles evaluating range of motion, 16 evaluating kinematic, four strength, seven electromyography and 18 evaluating more than one outcome. The studies presented moderate and high methodological quality. Patients with LBP, regardless of symptoms, showed a significant reduction in hip range of motion, especially hip internal rotation, reduction in the time to perform functional activities such as sit-to-stance-to-sit, sit-to-stand or walking, greater activation of the hamstrings and gluteus maximus muscles and weakness of the hip abductor and extensor muscles during specific tests and functional activities compared to healthy individuals.

CONCLUSION

Patients with LBP present changes in range of motion, task execution, activation, and hip muscle strength when compared to healthy individuals. Therefore, clinicians must pay greater attention to the assessment and management of the hip during the treatment of these patients.

SYSTEMATIC REVIEW REGISTRATION

International Prospective Register of Systematic Reviews (PROSPERO) (CRD42020213599).

The association between pain-related psychological variables and postural control in low back pain: A systematic review and meta-analysis

BACKGROUND

Alterations in postural control have been found in individuals with low back pain (LBP), particularly during challenging postural tasks. Moreover, higher levels of negative pain-related psychological variables are associated with increased trunk muscle activity, reduced spinal movement, and worse maximal physical performance in individuals with LBP.

RESEARCH QUESTION

Are pain-related psychological variables associated with postural control during static bipedal standing tasks in individuals with LBP?

METHODS

A systematic review and meta-analysis were conducted. Pubmed, Web of Science, and PsycINFO were searched until March 2023. Studies were included if they evaluated postural control during static bipedal standing in individuals with LBP by measuring center of pressure (CoP) variables, and reported at least one pain-related psychological variable. Correlation coefficients between pain-related psychological variables and CoP variables were extracted. Study quality was assessed with the "Quality In Prognosis Studies" tool (QUIPS). Random-effect models were used to calculate pooled correlation coefficients for different postural tasks. Sub-analyses were performed for positional or dynamic CoP variables. Certainty of evidence was assessed with an adjusted "Grading of Recommendations, Assessment, Development, and Evaluations" tool (GRADE). The protocol was registered on PROSPERO (CRD42021241739).

RESULTS

Sixteen studies (n = 723 participants) were included. Pain-related fear (16 studies) and pain catastrophizing (three studies) were the only reported pain-related psychological variables. Both pain-related fear (-0.04 < pooled r < 0.14) and pain catastrophizing (0.28 < pooled r < 0.29) were weakly associated with CoP variables during different postural tasks. For all associations, the certainty of evidence was very low.

SIGNIFICANCE

Pain-related fear and pain catastrophizing are only weakly associated with postural control during static bipedal standing in individuals with LBP, regardless of postural task difficulty. Certainty of evidence is very low thus it is conceivable that future studies accounting for current study limitations might reveal different findings.

Comparison of proprioceptive postural control strategies between prolonged standing induced low back pain developers and non-low back pain developers

BACKGROUND

Proprioception deficit has been suggested as a possible mechanism contributing for the impaired postural control in low back pain (LBP) patients. Whether proprioception deficit is a result of or a cause of LBP has not been investigated.

OBJECTIVE

The purpose of this study was to compare proprioceptive postural control strategies between prolonged standing induced low back pain developers (PDs) and non-pain developers (NPDs).

METHOD

Thirty-two healthy subjects performed 1-h prolonged standing and their ratings of perceived LBP have been recorded. Eight quiet standing trials for 60 s performed immediately before and after the prolonged standing. Postural control was challenged by muscle vibration and different postural conditions during quiet standing. Data were recorded using a force platform.

RESULTS

Forty percentage of participants is classified as PD. Before the prolonged standing, relative proprioceptive weighting was greater in the PD compared to NPD group (P = .029). Main effect of postural condition (F_1,24 = 5.21, P = .032) and interaction of time by group (F_1,24 = 8.08, P = .009) were significant for COP displacement in anteroposterior direction. Interaction of postural condition by group (F_1,26 = 7.82, P = .010) and time by group (F_1,26 = 9.71, P = .004) were significant for COP displacement in mediolateral direction. Main effect of postural condition (F_1,26 = 6.31, P = .018) and interaction of postural condition by group (F_1,26 = 7.07, P = .013) were significant for mean velocity in mediolateral direction.

CONCLUSION

The PD group has altered proprioceptive postural control strategies before and after prolonged standing. Proprioception deficit should not be considered to be solely an adaptive response and may be causal for LBP development.

The Effect of Lumbar Belts with Different Extensibilities on Kinematic, Kinetic, and Muscle Activity of Sit-to-Stand Motions in Patients with Nonspecific Low Back Pain

Although lumbar belts can be used for the treatment and prevention of low back pain, the role of the lumbar belt remains unclear without clear guidelines. This study aimed to investigate the effect of lumbar belts with different extensibilities on the kinematics, kinetics, and muscle activity of sit-to-stand motions in terms of motor control in patients with nonspecific low back pain. A total of 30 subjects participated in the study: 15 patients with nonspecific low back pain and 15 healthy adults. Participants performed the sit-to-stand motion in random order of three conditions: no lumbar belt, wearing an extensible lumbar belt, and wearing a non-extensible lumbar belt. The sit-to-stand motion's kinematic, kinetic, and muscle activity variables in each condition were measured using a three-dimensional motion analysis device, force plate, and surface electromyography. An interaction effect was found for the time taken, anterior pelvic tilt angle, and muscle activity of the vastus lateralis and biceps femoris. The two lumbar belts with different extensibilities had a positive effect on motor control in patients with nonspecific low back pain. Therefore, both types of extensible lumbar belts can be useful in the sit-to-stand motion, which is an important functional activity for patients with nonspecific low back pain.

Comparison of Kinematic Movement Patterns Between 2 Subgroups of Females With Low Back Pain and Healthy Women During Sit-to-Stand and Stand-to-Sit

The purpose of study was to compare the kinematic patterns of the thoracic, lumbar, and pelvis segments and hip joints between 2 low back pain subgroups and healthy women during sit-to-stand and stand-to-sit. Kinematic data of 44 healthy women and 2 subgroups of females with low back pain in 2 subgroups of movement system impairment model (rotation-extension [Rot.Ext] and rotation-flexion [Rot.Flex]) were recorded. Participants performed sit-to-stand and stand-to-sit at a preferred speed. Each task was divided into a pre buttock lifted off/on (pre-BOff/n) phase and a post-BOff/n phase. The Rot.Ext subgroup showed greater range of motion in the thoracic during pre-BOff phase of sit-to-stand (P < .001) and pre-BOn phase of stand-to-sit (P = .01) compared to the other 2 groups. The Rot.Flex subgroup displayed limited left hip joint excursion during sit-to-stand pre-BOff (P = .04) and stand-to-sit post-BOn phases (P = .02). The Rot.Flex subgroup showed greater pelvis tilt excursion during sit-to-stand post-BOff (P = .04) and stand-to-sit pre-BOn (P = .01) and post-BOn phases (P = .01). In subgroups of women with chronic low back pain, there were kinematic changes in adjacent body segments/joints of lumbar spine during sit-to-stand and stand-to-sit tasks.

Spinopelvic movement strategies during sit-to-stand and stand-to-sit in adult spinal deformity

BACKGROUND

Research interest on the impact of adult spinal deformity (ASD) on spinopelvic and whole body motion has increased over the past years. Studies focusing on overground walking, showed that patients with ASD indeed present with functional impairments. Functional tasks challenging the spinopelvic complex, such as sit-to-stand-to-sit, might identify clinically relevant biomechanical parameters and could further increase our insights on how ASD impacts functioning and disability.

RESEARCH QUESTION

Do patients with ASD use different spinopelvic strategies during sit-to-stand (STSt) and stand-to-sit (StTS) compared to healthy controls?

METHODS

In this prospective study, marker-based motion analysis and a subject-specific polynomial fit were used to assess spinopelvic kinematics (thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), trunk, pelvis) during STSt/StTS in 42 patients with ASD and 18 control subjects. All parameters were compared between controls and patients with ASD, divided in three groups based on their sagittal alignment (ASD 1: decompensated sagittal malalignment; ASD 2: compensated sagittal malalignment; ASD 3: scoliosis and normal sagittal alignment). Continuous kinematic and kinetic data were analyzed through statistical parametric mapping.

RESULTS

Patients with ASD showed decreased LL and increased trunk flexion and SVA during STSt/StTS compared to controls. These differences were mainly observed in sagittal deformity patients (ASD 1 and 2). In contrast, coronal patients (ASD 3) did not differ from controls. Dynamic LL and SVA significantly correlated with radiographic LL and SVA, however these relations decreased during the middle third of the motion cycle.

SIGNIFICANCE

Patients with ASD use aberrant spinopelvic strategies during STSt/StTS compared to healthy controls. Only partial correlation to static radiographic parameters suggests other mechanisms need to be identified in addition to spinal malalignment. These might include impaired neuromuscular control or muscle weakness. Further research on movement patterns during functional tasks might ultimately result in treatment strategies that aim to augment activity participation by targeting improvements in movement function.

Analysis of the Effect of Wearing Extensible and Non-Extensible Lumbar Belts on Biomechanical Factors of the Sit-to-Stand Movement and Pain-Related Psychological Factors Affecting Office Workers with Low Back Pain

This study aimed to investigate the effects of wearing extensible and non-extensible lumbar belt (LB) on biomechanical factors of the sit-to-stand (STD) movement and pain-related psychological factors affecting office workers with low back pain. Among 30 office workers, 15 with low back pain (LBP) were assigned to the experimental group and 15 healthy adults were assigned to the control group. The participants performed STD movement in random order of three different conditions: without LB (Condition 1), with extensible LB (Condition 2), and with non-extensible LB (Condition 3). Biomechanical variables of STD movement in each condition were measured using a three-dimensional motion analysis system and force plate. Pain-related psychological factors were measured only in the experimental group. Among the biomechanical factors of STD movement, an interaction effect was found in the maximum anterior pelvic tilt angle and total-phase range of motion of the trunk (p < 0.05). Pain intensity, pain-related anxiety, and pain catastrophizing were decreased in the conditions with lumbar belts (Conditions 2 and 3) compared to the condition without LB (Condition 1) (p < 0.05). Extensible and non-extensible lumbar belts engender biomechanically beneficial effects during STD movement in both office workers with LBP and healthy office workers. Further, pain intensity, pain-related anxiety, and pain catastrophizing were decreased in office workers with LBP. Therefore, both types of extensible lumbar belts may be helpful in the daily life of patients with LBP and office workers.

A Kinematic Comparison Between Sit-to-Stand Movements and Individual Cycles of the 5-Cycle Sit-to-Stand Test

OBJECTIVE

The 5-cycle sit-to-stand (5XSTS) test is frequently used to test physical function for different clinical populations, with time to complete as the measured outcome. This study evaluated the similarity of kinematics between a single cycle of the STS movement and individual cycles of the 5XSTS test.

METHODS

Lower extremity, pelvis, and thorax kinematic data were monitored as 20 participants (aged 18-40) completed 5 trials of the STS movement and 1 trial of the 5XSTS test. Correlations and root mean squared differences assessed the temporal and spatial similarities in kinematic patterns of sagittal plane joint angles at the ankles, knees, hips, and spine between single cycles of the STS movement and individual cycles of the 5XSTS test. Peak joint angles were obtained along with discrete angles at the start, seat off, and end of the movement.

RESULTS

Temporal and spatial similarity of kinematics for the ankles and hips were reduced over cycles 2 to 5 of the 5XSTS. Increased hip flexion was observed at the start of cycles 2 to 5 of the 5XSTS test. Increased knee and hip flexion were observed at the end of cycles 1 to 4 of the 5XSTS test.

CONCLUSIONS

Temporal patterns of sagittal plane joint angles captured in the first cycle of the 5XSTS represented those adopted for an isolated STS movement. Different initial conditions for cycles 2 to 5 of the 5XSTS 58 may have reduced temporal and spatial similarity of sagittal plane joint angles of the ankles and hips.

Trunk control during repetitive sagittal movements following a real-time tracking task in people with chronic low back pain

Precision of trunk movement has commonly been examined by testing relocation accuracy rather than evaluating accuracy of tracking dynamic movement. In this study we used a 3-D motion capture system to provide a novel real-time tracking task to assess trunk motor control at varying movement speeds between people with and without chronic non-specific low back pain (LBP). Eleven asymptomatic volunteers and 15 participants with chronic non-specific LBP performed 12 continuous cycles of trunk flexion-extension following real time visual feedback, during which, trunk motion was measured using eight optoelectronic infrared cameras. Significant time differences between the feedback and actual trunk motion were found between groups (P = 0.001). Both groups had similar variability of tracking accuracy when following the feedback (P > 0.05). However, tracking variability at a slow speed correlated (P = 0.03; r = 0.55) with the Fear-Avoidance Beliefs Questionnaire (FABQ) scores in those with LBP. This study shows that both asymptomatic people and individuals with LBP displayed anticipatory behaviour, however, the response of those with LBP was consistently delayed in tracking the visual feedback compared to the asymptomatic group. Additionally, the extent of variability of tracking accuracy over repeated tracking cycles was associated with the degree of fear of movement in people with LBP.

Lumbar Spine Kinematics in Asymptomatic People When Changing Body Position From Sitting to Standing

OBJECTIVE

The purpose of this study was to assess the lumbar spine kinematics in 3 movement axes in asymptomatic individuals in the sit-to-stand (STS) movement performed in a habitual, flexion, or extension manner.

METHODS

There were 30 participants (16 women, 14 men), aged 23 to 37 years. Each participant performed an STS test. We registered the total time of the STS movement and the maximum acceleration of the lumbar spine in the vertical, anteroposterior, and mediolateral axes. The examination of the movement pattern was performed with the use of a BTS G-sensor device.

RESULTS

The highest movement dynamics in the lumbar spine were observed during the STS performed in a habitual manner in the 3 axes (P < .01). The lowest movement dynamics ere associated with the extension STS pattern. The flexion pattern differed from the habitual one in total performance time in both groups (P < .01). There were no significant differences in kinematic lumbar spine between sexes.

CONCLUSION

The kinematics of the STS movement for asymptomatic individuals were characterized by significant variability in the maximum acceleration in the 3 axes. The highest movement dynamics were observed during the STS performed in a habitual manner, and the lowest dynamics with the extension pattern of STS.

Comparing the effects of aquatic exercises with or without high intensity on the functional status, muscular endurance, and performance of patients with chronic low back pain

BACKGROUND

The prevalence of low back pain is lower when physical fitness (aerobic and muscular) is higher. Strength exercises are important for subjects with low back pain, but there are few studies on the inclusion of aerobic exercise in low back pain programs. The aim of this study was to compare the effects of aquatic exercises with or without high-intensity component on the functional status, lumbar and abdominal muscle endurance, and performance of subjects with chronic low back pain.

METHODS

Forty-eight volunteers between 20 and 60 years old were randomly allocated to an experimental group AEDWR (aquatic exercises plus deep-water running group, N.=25) or to a control group AE (aquatic exercises only group, N.=23). The dependent variables included functional status (Repeated Sit-to-Stand test), lumbar (Sorensen test) and abdominal (One Minute Abdominal test) muscle endurance, and physical performance (Maximum Physical Fitness test), which were measured before and after the 9-week intervention and at 21 weeks of follow-up.

RESULTS

Lumbar endurance was higher in the AEDWR group at the end of the treatment, with a mean difference (MD) of 43.2 seconds, 95% confidence intervals (CI) (9.6; 76.7), P=0.01, d̅=0.74, and better in the follow-up with MD=40.2 seconds, 95% CI (7.1; 73.3), P=0.02, d̅=0.71, than in the AE group. Participant performance also improved on the 9^th week in the AEDWR group, with an MD=0.53 kgf, 95% CI (0.008; 0.98), P=0.02, d̅=0.60.

CONCLUSIONS

The addition of deep-water running exercise to aquatic exercises improved lumbar muscle endurance and performance when compared with aquatic exercises only, and this effect was maintained during the follow-up to lumbar muscle endurance.

Linear and Non-linear Dynamic Methods Toward Investigating Proprioception Impairment in Non-specific Low Back Pain Patients

Central nervous system (CNS) uses vision, vestibular, and somatosensory information to maintain body stability. Research has shown that there is more lumbar proprioception error among low back pain (LBP) individuals as compared to healthy people. In this study, two groups of 20 healthy people and 20 non-specific low back pain (NSLBP) participants took part in this investigation. This investigation focused on somatosensory sensors and in order to alter proprioception, a vibrator (frequency of 70 Hz, amplitude of 0.5 mm) was placed on the soleus muscle area of each leg and two vibrators were placed bilaterally across the lower back muscles. Individuals, whose vision was occluded, were placed on two surfaces (foam and rigid) on force plate, and trunk angles were recorded simultaneously. Tests were performed in eight separate trials; the independent variables were vibration (four levels) and surface (two levels) for within subjects and two groups (healthy and LBP) for between subjects (4 × 2 × 2). MANOVA and multi-factor ANOVA tests were done. Linear parameters for center of pressure (COP) [deviation of amplitude, deviation of velocity, phase plane portrait (PPP), and overall mean velocity] and non-linear parameters for COP and trunk angle [recurrence quantification analysis (RQA) and Lyapunov exponents] were chosen as dependent variables. Results indicated that NSLBP individuals relied more on ankle proprioception for postural stability. Similarly, RQA parameters for the COP on both sides and for the trunk sagittal angle indicated more repeated patterns of movement among the LBP cohort. Analysis of short and long Lyapunov exponents showed that people with LBP caused no use of all joints in their bodies (non-flexible), are less stable than healthy subjects.

Changes in the Organization of the Secondary Somatosensory Cortex While Processing Lumbar Proprioception and the Relationship With Sensorimotor Control in Low Back Pain

OBJECTIVES

Patients with nonspecific low back pain (NSLBP) rely more on the ankle compared with the lower back proprioception while standing, perform sit-to-stand-to-sit (STSTS) movements slower, and exhibit perceptual impairments at the lower back. However, no studies investigated whether these sensorimotor impairments relate to a reorganization of the primary and secondary somatosensory cortices (S1 and S2) and primary motor cortex (M1) during proprioceptive processing.

MATERIALS AND METHODS

Proprioceptive stimuli were applied at the lower back and ankle muscles during functional magnetic resonance imaging in 15 patients with NSLBP and 13 controls. The location of the activation peaks during the processing of proprioception within S1, S2, and M1 were determined and compared between groups. Proprioceptive use during postural control was evaluated, the duration to perform 5 STSTS movements was recorded, and participants completed the Fremantle Back Awareness Questionnaire (FreBAQ) to assess back-specific body perception.

RESULTS

The activation peak during the processing of lower back proprioception in the right S2 was shifted laterally in the NSLBP group compared with the healthy group (P=0.007). Moreover, patients with NSLSP performed STSTS movements slower (P=0.018), and reported more perceptual impairments at the lower back (P<0.001). Finally, a significant correlation between a more lateral location of the activation peak during back proprioceptive processing and a more disturbed body perception was found across the total group (ρ=0.42, P=0.025).

CONCLUSIONS

The results suggest that patients with NSLBP show a reorganization of the higher-order processing of lower back proprioception, which could negatively affect spinal control and body perception.

Does manual therapy affect functional and biomechanical outcomes of a sit-to-stand task in a population with low back pain? A preliminary analysis

Introduction

Manual therapy (MT) hypothetically affects discrepant neuromuscular control and movement observed in populations with low back pain (LBP). Previous studies have demonstrated the limited influence of MT on movement, predominately during range of motion (ROM) testing. It remains unclear if MT affects neuromuscular control in mobility-based activities of daily living (ADLs). The sit-to-stand (STS) task represents a commonly-performed ADL that is used in a variety of clinical settings to assess functional and biomechanical performance.

Objective

To determine whether MT affects functional performance and biomechanical performance during a STS task in a population with LBP.

Methods

Kinematic data were recorded from the pelvis and thorax of participants with LBP, using an optoelectronic motion capture system as they performed a STS task before and after MT from November 2011 to August 2014. MT for each participant consisted of two high-velocity low-amplitude spinal manipulations, as well as two grade IV mobilizations of the lumbar spine and pelvis targeted toward the third lumbar vertebra and sacroiliac joint in a side-lying position; the order of these treatments was randomized. Pelvis and thorax kinematic data were used to derive the time-varying lumbar angle in the sagittal plane for each STS trial. The difference between the maximum and minimum lumbar angles during the STS trial determined the sagittal ROM that was used as the biomechanical outcome. Time to complete each STS trial was used as a functional measure of performance. Pre-MT and post-MT values for the lumbar sagittal ROM and time to completion were statistically analysed using paired samples t-tests.

Results

Data were obtained from 40 participants with 35 useful datasets (NRS = 3.3 ± 1.2; 32.4 ± 9.8 years; 16 females, 19 males). After MT, lumbar sagittal ROM increased by 2.7 ± 5.5 degrees (p = 0.007). Time to complete the STS test decreased by 0.4 ± 0.4 s (p < 0.001).

Discussion

These findings provide preliminary evidence that MT might influence the biomechanical and functional performance of an STS task in populations with LBP. The MT intervention in this study involved a combination of spinal manipulations and mobilizations. Future work will expand upon these data as a basis for targeted investigations on the effects of either spinal manipulation and mobilization on neuromuscular control and movement in populations with LBP.

Kinematic Characteristics of Sit-to-Stand Movements in Patients With Low Back Pain: A Systematic Review

OBJECTIVE

The purpose of this review was to identify different kinematic characteristics between the movements of sit-to-stand-to-sit, sit-to-stand, or stand-to-sit of individuals with and without low back pain (LBP).

METHODS

A systematic search was conducted on scientific databases. The analyzed kinematic variables were duration of the movement, reproduction of the movement, ranges of motion, velocity, and acceleration. The studies were appraised for methodological quality using the Downs & Black scale and for the level of evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach.

RESULTS

After all screening stages, this systematic review comprised 8 cross-sectional studies. When comparing the patients with LBP vs controls, patients with LBP take longer to perform the sit-to-stand-to-sit, sit-to-stand, and stand-to sit movements (eg, 9.33 ± 1.49 seconds vs 8.29 ± 1.23 seconds in the sit-to-stand-to-sit movement), show decreased mobility of the lumbar spine (eg, 26.21° ± 8.76° vs 32.07° ± 6.77° in the sit-to-stand-to-sit movement) and the hip (eg, 51.0° vs 77.25° in the sit-to-stand movement), present decreased velocity of the trunk (eg, 95.31° ± 25.13°/s vs 138.23° ± 23.42°/s in the sit-to-stand-to-sit movement) and the hip (eg, 46° ± 13°/s vs 69° ± 13°/s in the sit-to-stand movement), and decreased overall acceleration of the trunk (eg, 280.19° ± 113.08°/s² vs 460.16° ± 101.49°/s² in the sit-to-stand-to-sit movement), besides presenting greater variability of the trunk (eg, 5.53° ± 0.48° vs 4.32° ± 0.46° in the sit-to-stand movement).

CONCLUSION

There are kinematic alterations in the lumbar spine, the hip, and the trunk of patients with LBP. However, information about pelvic and overall trunk mobility, velocity, and acceleration of the lumbar spine; and mobility, speed, and acceleration of hip and pelvis remain incipient in individuals with LBP. Based on the Grading of Recommendations Assessment, Development, and Evaluation criteria, the results of this review indicate that there is low scientific evidence on the characteristics of the kinematic variables (duration of the movement, reproduction of the movement, range of motion, velocity, and acceleration) of the trunk, lumbar spine, pelvis, and hip in patients with LBP.

Differences in brain processing of proprioception related to postural control in patients with recurrent non-specific low back pain and healthy controls

Patients with non-specific low back pain (NSLBP) show an impaired postural control during standing and a slower performance of sit-to-stand-to-sit (STSTS) movements. Research suggests that these impairments could be due to an altered use of ankle compared to back proprioception. However, the neural correlates of these postural control impairments in NSLBP remain unclear. Therefore, we investigated brain activity during ankle and back proprioceptive processing by applying local muscle vibration during functional magnetic resonance imaging in 20 patients with NSLBP and 20 controls. Correlations between brain activity during proprioceptive processing and (Airaksinen et al., 2006) proprioceptive use during postural control, evaluated by using muscle vibration tasks during standing, and (Altmann et al., 2007) STSTS performance were examined across and between groups. Moreover, fear of movement was assessed. Results revealed that the NSLBP group performed worse on the STSTS task, and reported more fear compared to healthy controls. Unexpectedly, no group differences in proprioceptive use during postural control were found. However, the relationship between brain activity during proprioceptive processing and behavioral indices of proprioceptive use differed significantly between NSLBP and healthy control groups. Activity in the right amygdala during ankle proprioceptive processing correlated with an impaired proprioceptive use in the patients with NSLBP, but not in healthy controls. Moreover, while activity in the left superior parietal lobule, a sensory processing region, during back proprioceptive processing correlated with a better use of proprioception in the NSLBP group, it was associated with a less optimal use of proprioception in the control group. These findings suggest that functional brain changes during proprioceptive processing in patients with NSLBP may contribute to their postural control impairments.

Association Between Sensorimotor Impairments and Functional Brain Changes in Patients With Low Back Pain: A Critical Review

Low back pain (LBP) coincides with sensorimotor impairments, for example, reduced lumbosacral tactile and proprioceptive acuity and postural control deficits. Recent functional magnetic resonance imaging studies suggest that sensorimotor impairments in LBP may be associated with brain changes. However, no consensus exists regarding the relationship between functional brain changes and sensorimotor behavior in LBP. Therefore, this review critically discusses the available functional magnetic resonance imaging studies on brain activation related to nonnociceptive somatosensory stimulation and motor performance in individuals with LBP. Four electronic databases were searched, yielding nine relevant studies. Patients with LBP showed reduced sensorimotor-related brain activation and a reorganized lumbar spine representation in higher-order (multi)sensory processing and motor regions, including primary and secondary somatosensory cortices, supplementary motor area, and superior temporal gyrus. These results may support behavioral findings of sensorimotor impairments in LBP. In addition, patients with LBP displayed widespread increased sensorimotor-evoked brain activation in regions often associated with abnormal pain processing. Overactivation in these regions could indicate an overresponsiveness to sensory inputs that signal potential harm to the spine, thereby inducing overgeneralized protective responses. Hence, functional brain changes could contribute to the development and recurrence of LBP. However, future studies investigating the causality between sensorimotor-related brain function and LBP are imperative.

Kinematics of the Spine During Sit-to-Stand Movement Using Motion Analysis Systems: A Systematic Review of Literature

CONTEXT

Clinical evaluation of the spine is commonplace in musculoskeletal therapies, such as physiotherapy, physical medicine/rehabilitation, osteopathic, and chiropractic clinics. Sit-to-stand (STS) is one of the most mechanically demanding daily activities and crucial to independence. Difficulty or inability to perform STS is common in individuals with a variety of motor disabilities, such as low back pain (LBP).

OBJECTIVE

The purpose of this systematic review was to evaluate available evidence in literature to determine 2-dimensional and 3-dimensional kinematics of the spine during STS in patients with LBP and healthy young adult participants using motion analysis systems (electromagnetic and marker based).

METHODS

Electronic databases (PubMed/MEDLINE [National Library of Medicine], Scopus, ScienceDirect, and Google Scholar) were searched between January 2002 and February 2017. Additionally, the reference lists of the articles that met the inclusion criteria were also searched. Prospective studies published in peer-reviewed journals, with full text available in English, investigating the kinematics of the spine during STS in healthy subjects (mean age between 18 and 50 y) or in patients with LBP using motion analysis systems, were included. Sixteen studies fulfilled the eligibility criteria. All information relating to methodology and kinematic modeling of the spine segments along with the outcome measures was extracted from the studies identified for synthesis.

RESULTS

The results indicated that the kinematics of the spine are greatly changed in patients with LBP. In order to develop a better understanding of spine kinematics, studies recommended that the trunk should be analyzed as a multisegment. It has been shown that there is no difference between the kinematics of patients with LBP and healthy population when the spine is analyzed as a single segment. Furthermore, between-gender differences are present during STS movement.

CONCLUSION

This review provided a valuable summary of the research to date examining the kinematics of the spine during STS.

Postural sensorimotor training versus sham exercise in physiotherapy of patients with chronic non-specific low back pain: An exploratory randomised controlled trial

Sensorimotor training (SMT) is popularly applied as exercise in rehabilitation settings, particularly for musculoskeletal pain. With insufficient evidence on its effect on pain and function, this exploratory randomised controlled trial investigated the potential effects of SMT in rehabilitation of chronic non-specific low back pain. Two arms received 9x30 minutes physiotherapy with added interventions: The experimental arm received 15 minutes of postural SMT while the comparator arm performed 15 minutes of added sub-effective low-intensity training. A treatment blinded tester assessed outcomes at baseline 2-4 days prior to intervention, pre- and post-intervention, and at 4-week follow-up. Main outcomes were pain and functional status assessed with a 0-100mm visual analogue scale and the Oswestry Disability Questionnaire. Additionally, postural control was analysed using a video-based tracking system and a pressure plate during perturbed stance. Robust, nonparametric multivariate hypothesis testing was performed. 22 patients (11 females, aged 32 to 75 years) with mild to moderate chronic pain and functional limitations were included for analysis (11 per arm). At post-intervention, average values of primary outcomes improved slightly, but not to a clinically relevant or statistically significant extent. At 4-week follow-up, there was a significant improvement by 12 percentage points (pp) on the functional status questionnaire in the SMT-group (95% confidence intervall (CI) = 5.3pp to 17.7pp, p < 0.001) but not in the control group (4 pp improvement, CI = 11.8pp to 19.2pp). However, group-by-time interaction effects for functional status (Q = 3.3, 19 p = 0.07) and pain (Q = 0.84, p = 0.51) were non-significant. Secondary kinematic outcomes did not change over time in either of the groups. Despite significant improvement of functional status after SMT, overall findings of this exploratory study suggest that SMT provides no added benefit for pain reduction or functional improvement in patients with moderate chronic non-specific low back pain.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02304120 and related study protocol, DOI: 10.1186/1471-2474-15-382.

Assessment of sit-to-stand movement in nonspecific low back pain: a comparison study for psychometric properties of field-based and laboratory-based methods

One of the most difficult tasks associated with the management of nonspecific low back pain (LBP) is its clinical assessment. Objective functional methods have been developed for assessment. However, few studies have used daily activities such as sit-to-stand (STS). The aim was to compare the psychometric properties of two commonly used STS assessment methods. A test-retest reliability study design was used. Participants with nonspecific LBP performed the 30-s chair stand test (30CST) and the STS test in Balance Master, which measures weight transfer, rising index and centre of gravity sway velocity. The same tests were reperformed after 48-72 h. The intraclass correlation coefficient (ICC), standard error of measurement (SEM), minimal detectable change and coefficient of variation were calculated to compare the reliability. The correlations between the tests, the Oswestry Disability Index and pain intensity were examined for validation. The 30CST had very high intrarater reliability (ICC=0.94). The variables of STS test in Balance Master had moderate intrarater reliability (ICC=0.62-0.69). There were significant correlations between the 30CST, Oswestry Disability Index and pain intensity at activity (P<0.01). The rising index was the only one variable that was significantly correlated with pain intensity at activity (P<0.05). The 30CST as the field-based method to measure STS movement was better than the laboratory-based method in terms of their psychometric properties. Moreover, the 30CST was associated with disability and pain related to LBP. The 30CST is a simple, cheap, less time consuming and psychometrically appropriate method to use in individuals with nonspecific LBP.

Associations between Measures of Structural Morphometry and Sensorimotor Performance in Individuals with Nonspecific Low Back Pain

BACKGROUND AND PURPOSE

To date, most structural brain imaging studies in individuals with nonspecific low back pain have evaluated volumetric changes. These alterations are particularly found in sensorimotor-related areas. Although it is suggested that specific measures, such as cortical surface area and cortical thickness, reflect different underlying neural architectures, the literature regarding these different measures in individuals with nonspecific low back pain is limited. Therefore, the current study was designed to investigate the association between the performance on a sensorimotor task, more specifically the sit-to-stand-to-sit task, and cortical surface area and cortical thickness in individuals with nonspecific low back pain and healthy controls.

MATERIALS AND METHODS

Seventeen individuals with nonspecific low back pain and 17 healthy controls were instructed to perform 5 consecutive sit-to-stand-to-sit movements as fast as possible. In addition, T1-weighted anatomic scans of the brain were acquired and analyzed with FreeSurfer.

RESULTS

Compared with healthy controls, individuals with nonspecific low back pain needed significantly more time to perform 5 sit-to-stand-to-sit movements (P < .05). Brain morphometric analyses revealed that cortical thickness of the ventrolateral prefrontal cortical regions was increased in patients with nonspecific low back pain compared with controls. Furthermore, decreased cortical thickness of the rostral anterior cingulate cortex was associated with lower sit-to-stand-to-sit performance on an unstable support surface in individuals with nonspecific low back pain and healthy controls (r = -0.47, P < .007). In addition, a positive correlation was found between perceived pain intensity and cortical thickness of the superior frontal gyrus (r = 0.70, P < .002) and the pars opercularis of the inferior ventrolateral prefrontal cortex (r = 0.67, P < .004). Hence, increased cortical thickness was associated with increased levels of pain intensity in individuals with nonspecific low back pain. No associations were found between cortical surface area and the pain characteristics in this group.

CONCLUSIONS

The current study suggests that cortical thickness may contribute to different aspects of sit-to-stand-to-sit performance and perceived pain intensity in individuals with nonspecific low back pain.

Structural Brain Connectivity and the Sit-to-Stand-to-Sit Performance in Individuals with Nonspecific Low Back Pain: A Diffusion Magnetic Resonance Imaging-Based Network Analysis

Individuals with nonspecific low back pain (NSLBP) show an impaired sensorimotor control. They need significantly more time to perform five consecutive sit-to-stand-to-sit (STSTS) movements compared with healthy controls. Optimal sensorimotor control depends on the coactivation of many brain regions, which have to operate as a coordinated network to achieve correct motor output. Therefore, the examination of brain connectivity from a network perspective is crucial for understanding the factors that drive sensorimotor control. In the current study, potential alterations in structural brain networks of individuals with NSLBP and the correlation with the performance of the STSTS task were investigated. Seventeen individuals with NSLBP and 17 healthy controls were instructed to perform five consecutive STSTS movements as fast as possible. In addition, data of diffusion magnetic resonance imaging were acquired and analyzed using a graph theoretical approach. Results showed that individuals with NSLBP needed significantly more time to perform the STSTS task compared with healthy controls (p < 0.05). Both groups exhibited small-world properties in their structural networks. However, local efficiency was significantly decreased in the patients with NSLBP compared with controls (p < 0.05, false discovery rate [FDR] corrected). Moreover, global efficiency was significantly correlated with the sensorimotor task performance within the NSLBP group (r = -0.73, p = 0.002). Our data show disrupted network organization of white matter networks in patients with NSLBP, which may contribute to their persistent pain and sensorimotor disabilities.

Proprioceptive use and sit-to-stand-to-sit after lumbar microdiscectomy: The effect of surgical approach and early physiotherapy

BACKGROUND

Individuals with non-specific low back pain show decreased reliance on lumbosacral proprioceptive signals and slower sit-to-stand-to-sit performance. However, little is known in patients after lumbar microdiscectomy.

METHODS

Patients were randomly assigned into transmuscular (n=12) or paramedian lumbar surgery (n=13). After surgery, the same patients were randomly assigned into individualized active physiotherapy starting 2 weeks after surgery (n=12) or usual care (n=13). Primary outcomes were center of pressure displacement during ankle and back muscles vibration (to evaluate proprioceptive use), and the duration of five sit-to-stand-to-sit movements, evaluated at 2 (baseline), 8 and 24 weeks after surgery.

FINDINGS

Two weeks after surgery, all patients showed smaller responses to back compared to ankle muscles vibration (P<0.05). Patients that underwent a transmuscular surgical procedure and patients that received physiotherapy switched to larger responses to back muscles vibration at 24 weeks, compared to 2 weeks after surgery (P<0.005), although not seen in the paramedian group and usual care group (P>0.05). Already 8 weeks after surgery, the physiotherapy group needed significantly less time to perform five sit-to-stand-to-sit movements compared to the usual care group (P<0.05).

INTERPRETATION

Shortly after lumbar microdiscectomy, patients favor reliance on ankle proprioceptive signals over lumbosacral proprioceptive reliance to maintain posture, which resembles the behavior of patients with non-specific low back pain. However, early active physiotherapy after lumbar microdiscectomy facilitated higher reliance on lumbosacral proprioceptive signals and early improvement of sit-to-stand-to-sit performance. Transmuscular lumbar surgery favoured recovery of lumbosacral proprioception 6 months after surgery.

CLINICAL TRIAL NUMBER

NCT01505595.

Resting-State Functional Connectivity of the Sensorimotor Network in Individuals with Nonspecific Low Back Pain and the Association with the Sit-to-Stand-to-Sit Task

Individuals with nonspecific low back pain (NSLBP) show a decreased sit-to-stand-to-sit (STSTS) performance. This dynamic sensorimotor task requires integration of sensory and motor information in the brain. Therefore, a better understanding of the underlying central mechanisms of impaired sensorimotor performance and the presence of NSLBP is needed. The aims of this study were to characterize differences in sensorimotor functional connectivity in individuals with NSLBP and to investigate whether the patterns of sensorimotor functional connectivity underlie the impaired STSTS performance. Seventeen individuals with NSLBP and 17 healthy controls were instructed to perform five consecutive STSTS movements as fast as possible. Based on the center of pressure displacement, the total duration of the STSTS task was determined. In addition, resting-state functional connectivity images were acquired and analyzed on a multivariate level using both functional connectivity density mapping and independent component analysis. Individuals with NSLBP needed significantly more time to perform the STSTS task compared to healthy controls. In addition, decreased resting-state functional connectivity of brain areas related to the integration of sensory and/or motor information was shown in the individuals with NSLBP. Moreover, the decreased functional connectivity at rest of the left precentral gyrus and lobule IV and V of the left cerebellum was associated with a longer duration of the STSTS task in both individuals with NSLBP and healthy controls. In summary, individuals with NSLBP showed a reorganization of the sensorimotor network at rest, and the functional connectivity of specific sensorimotor areas was associated with the performance of a dynamic sensorimotor task.

Impaired postural control reduces sit-to-stand-to-sit performance in individuals with chronic obstructive pulmonary disease

Background

Functional activities, such as the sit-to-stand-to-sit (STSTS) task, are often impaired in individuals with chronic obstructive pulmonary disease (COPD). The STSTS task places a high demand on the postural control system, which has been shown to be impaired in individuals with COPD. It remains unknown whether postural control deficits contribute to the decreased STSTS performance in individuals with COPD.

Methods

Center of pressure displacement was determined in 18 individuals with COPD and 18 age/gender-matched controls during five consecutive STSTS movements with vision occluded. The total duration, as well as the duration of each sit, sit-to-stand, stand and stand-to-sit phase was recorded.

Results

Individuals with COPD needed significantly more time to perform five consecutive STSTS movements compared to healthy controls (19±6 vs. 13±4 seconds, respectively; p = 0.001). The COPD group exhibited a significantly longer stand phase (p = 0.028) and stand-to-sit phase (p = 0.001) compared to the control group. In contrast, the duration of the sit phase (p = 0.766) and sit-to-stand phase (p = 0.999) was not different between groups.

Conclusions

Compared to healthy individuals, individuals with COPD needed significantly more time to complete those phases of the STSTS task that require the greatest postural control. These findings support the proposition that suboptimal postural control is an important contributor to the decreased STSTS performance in individuals with COPD.