Lumbar Flexion During Driving: Establishing a Methodology for Characterising Real-Time Posture Data Collected by Innovative Technology

Objective To determine a methodology for the analysis of real-time driving posture data in the low back pain population. Background The strength of the relationship between driving posture and low back pain is yet to be defined due to the lack of studies in the field using validated and repeatable posture measurement tools. Reliable and validated real-time measurement tools are now available, yet reliable methods of analysis of these data are yet to be established. Method Ten occupational drivers completed a typical work shift while wearing an inertial motion sensor system (dorsaVi ViMove). Real-time lumbar flexion data were extracted, with test–retest reliability of mean lumbar flexion, peak lumbar flexion, and standard deviation of lumbar flexion analysed at different times across a work shift, and in different sections within a drive. Results Mean lumbar flexion was highly repeatable over numerous drives in one day, with greater test–retest reliability if the first five minutes of driving data were excluded. Peak lumbar flexion had acceptable test-retest reliability over numerous drives in one day, while standard deviation of lumbar flexion was not a repeatable measure. Conclusion Mean lumbar flexion was a reliable outcome for characterising driving posture in drivers with low back pain. Peak lumbar flexion may be used if appropriate to the individual study. Standard deviation of lumbar flexion is not a reliable posture outcome. Application This paper provides a reliable methodology for analysis of real-time driving posture data in occupational drivers with low back pain.

Moving Toward Individual-Specific Automotive Seat Design: How Individual Characteristics and Time Alter the Selected Lumbar Support Prominence

Objective To explore how individual characteristics influence selected lumbar support prominence (LSP), seated lumbar flexion, seatback average pressure, contact area, and center of pressure (CoP) location before and after 1 hr of driving. Background An LSP can alter posture and may reduce low back pain during prolonged driving. Although LSP preference varies across individuals and may change over time, few investigations have explored the time-varying response to individually selected adjustable seat parameters. Method Forty individuals selected LSP settings in an automotive seat through a series of systematic adjustment trials. The average LSP setting was fixed for a 1-hr driving simulation, followed by one final adjustment trial. Regressions were performed between individual characteristics and selected LSP, lumbar posture, and measures of seatback pressure from the initial adjustment trials. ANOVAs were performed to determine the effect of time and sex on these dependent variables. Discomfort was also monitored throughout the protocol. Results Individual’s standing lumbar lordosis, selected LSP, and height and mass were significant predictors for seated lumbar flexion, seatback average pressure, and contact area, respectively. Discomfort levels remained low; however, following the driving protocol, individuals altered their posture to decrease lumbar flexion and increase seatback average pressure without significant adjustments to the LSP. Conclusion These findings highlight individual characteristics to consider in automotive seat design and that the method for determining LSP settings may facilitate appropriate LSP selection. Application A systematic method to determine LSP settings may reduce discomfort and automate seat adjustments, such that only short-term postural adjustments may be required.

Comparison of Flexion Relaxation Phenomenon Between Female Yogis and Matched Non- Athlete Group

Background: Trunk flexion is a common exercise during daily activities. Flexion relaxation phenomenon (FRP) occurs during forward bending in which there is a sudden silence of erector spinae (ES) muscles. The pattern of forward bending differs in yoga practitioners. This learned pattern probably predisposes yogis to injuries.The hypothesis of this study was that FRP differs in yogis in comparison to non-yogis individuals.Methods: This observational cross-sectional study was performed on 60 women assigned into yogis and non-athlete groups. Each participant was asked to bend forward and then return to the initial position. ES activity was recorded at L3 level, 4 cm from mid line during the trial. Trunk inclination and lumbar flexion angles were calculated at FRP onset and cessation moments. Results: The FRP phenomenon occurred in 80% of yoga practitioners in comparison to 96.7% in the control group. Trunk inclination angle was significantly greater at FRP initiation in yogis compared to control group. Lumbar flexion angle was not different between the groups. Conclusions: It is concluded that the altered pattern of forward bending observed in yogis may change patterns of ES muscles activity if it becomes part of a person's daily lifestyle which might predispose these muscles to fatigue and subsequent injuries.

Segmental spine mobility differences between lumbar flexion- and extension-based movement syndromes in patients with low back pain

BACKGROUND: The Movement System Impairment (MSI) model is useful for identifying spine-hip mobility and motor control deficits that may contribute to low back pain (LBP). While previous studies have found differences in global spine-hip movement impairments between lumbar MSI subgroups, no studies have compared segmental spine movement impairments between these subgroups. Therefore, the purpose of this study is to analyze segmental lumbar mobility in participants with LBP and a lumbar flexion- or extension-based MSI. METHODS: Forty participants with subacute-chronic LBP were placed into one of three age groups (< 35, 35–54, or > 54 years-old) and then classified into a flexion- or extension-based MSI sub-group. Segmental lumbar range of motion (ROM) was measured in degrees using a skin-surface device. Total lumbar and segmental flexion and extension ROM of L1-L2 to L5-S1 was compared between MSI sub-groups for each age group using separate two-way ANOVAs. RESULTS: Significant main effects were found for the independent variables of MSI subgroup and age. Participants in all three age groups with a flexion-based MSI displayed significantly less lumbar extension (-0.6∘) at L4-5 as compared to participants with an extension-based MSI (-2.1∘), p= 0.03. In addition, lumbar total and segmental ROM was significantly less for older individuals in both subgroups. CONCLUSIONS: Individuals with LBP may demonstrate a pattern of lumbar segmental hypomobility in the opposite direction of their MSI. Future studies may investigate the added value of direction-specific spinal mobilization to a program of MSI-based exercise.

Association of lumbar spine mobility and hamstring tightness in dental practitioners

Introduction and Aim: The decrease in lumbar spine mobility and hamstring tightness can be caused due to the lack of regular exercise and awkward postures exposed at the workplace due to an individual's occupation. It can be expressed due to the awkward posture during dental practice as well and this can be controlled by doing regular exercises.The aim of the present study is to analyze the association of lumbar spine mobility and hamstring tightness in dental practitioners. Materials and Methods: The study is conducted in a Private dental college and hospital for the dental practitioners who work for more than 4 hours in a day. The hamstring tightness is measured using the goniometer and lumbar spine flexibility is measured using an inch tape. The measurements are tabulated and analyzed statistically for the correlation of lumbar spine flexibility with hamstring tightness using the SPSS tool. Results: The collected data are analyzed statistically using correlation coefficient and the findings concluded that they have a low positive correlation. The mean value of lumbar flexion range is 19.37 cm and mean value of the hamstring tightness is 27.8°, the correlation coefficient r is 0.473. Majority of female participants have increased hamstring tightness with a maximum range of 30° and around 11% of male participants have a restriction range of 25°. Similarly, around 8% of female participants have a lumbar flexion range of around 21cm, However, there is no significant difference between the gender in both the variables with p value equals 0.35 and 0.53 (p > 0.05) respectively. Conclusion: From the obtained results it can be concluded that there is a low positive correlation between hamstring tightness and the lumbar flexion range. The findings suggest that the dental practitioners are prone to hamstring tightness which in turn can induce reduced lumbar spine mobility and impacts stress on the lumbar spine leading to low back pain.

Myofascial release versus Mulligan sustained natural apophyseal glides’ immediate and short-term effects on pain, function, and mobility in non-specific low back pain

Background Myofascial release (MFR) and Mulligan Sustained Natural Apophyseal Glides (SNAGs) are manual therapy techniques routinely practiced in the management of non-specific low back pain (NSLBP). As a solo intervention or along with other therapies, both methods have reported positive results for individuals with NSLBP. However, which technique improves NSLBP-related pain, restricted range of motion (ROM) and disability, warrants further research. Objective To study the comparative effects of MFR and SNAGs on pain, disability, functional ability, and lumbar ROM in NSLBP. Method A parallel-group study was conducted at tertiary care hospitals. Sixty-five Sub-acute or chronic NSLBP patients were allocated to receive strengthening exercises along with either MFR (n = 33) or SNAGs (n = 32) for six treatment sessions over one week. An independent assessor evaluated outcome measures such as the Visual Analog Scale (VAS), Patient-Specific Function Scale (PSFS), and ROM at baseline, immediate (after 1st treatment), and short-term (post-sixth day of the intervention). The Modified Oswestry disability index (MODI) was assessed at baseline and short-term. Results Within-group analysis found clinically and statistically significant (p < 0.05) changes for VAS and PSFS at immediate and short-term for both the groups. The lumbar extension also showed improvement immediately and in the short-term. Improvement in Lumbar flexion was seen only in the SNAGs group over the short-term. A statistically significant improvement was seen for MODI in both the groups but was not clinically significant in the MFR group. The analysis observed no statistically significant difference (p < 0.05) between the groups at both the immediate and short-term. Conclusions Pain and restricted function associated with NSLBP can be improved using SNAGs or MFR, along with strengthening exercises. For limited lumbar flexion ROM, Mulligan SNAGs have a better outcome than MFR over the short-term. Hence, both manual therapy techniques can be incorporated along with exercises for immediate and short-term management of sub-acute to chronic NSLBP. Clinical Trial Registration. CTRI/2018/12/016787 (http://ctri.nic.in/Clinicaltrials/).

Test–Retest Reliability of an iPhone® Inclinometer Application to Assess the Lumbar Joint Repositioning Error in Non-Specific Chronic Low Back Pain

Background: The joint position sense (JPS) has been used as an indirect marker of proprioception in subjects with non-specific chronic low back pain (NSCLBP), showing impairment in previous studies. It seems necessary to devise reliable tests to measure proprioceptive deficits in subjects with NSLBP. The objective of this study was to analyse the test–retest reliability and smallest real difference (SRD) of lumbar proprioception through the JPS indicator in a sample of patients with NSCLBP. Methods: Fifty participants with NSCLBP performed three repetitions of 30° lumbar flexion while standing and sitting using the iPhone® inclinometer application to measure the lumbar joint repositioning error. For the reliability analysis, we performed an intra-session test–retest. Results: The total sample ICC values were excellent for standing (0.96) and sitting (0.93) 30° lumbar flexion. In addition, our results showed that, for the total sample, an SRD < 12% can be considered as a true change in proprioception concerning this procedure. On the other hand, men have better reliability than women in both standing and sitting positions. Additionally, the sitting position has better reliability than the standing position. The standard error of measurement (SEM) percentage was 4.2 for standing and 3.8 for sitting. The SRD percentage was 11.6 for standing and 10.4 for sitting. Conclusions: The iPhone® inclinometer seems reliable for assessing proprioceptive ability through the lumbar joint repositioning error in subjects with NSCLBP in both standing (ICC = 0.96) and sitting (ICC = 0.93) positions. This technological device showed a lower measurement error for sitting position (SRD < 12%).

Paravertebral Muscle Mechanical Properties and Spinal Range of Motion in Patients with Acute Neck or Low Back Pain: A Case-Control Study

Our aims were to identify potential differences in muscle mechanical properties (MMPs) of cervical and lumbar tissues and in spinal range of motion (ROM) between patients with acute low back pain (LBP) or acute neck pain (NP) and healthy controls, and to identify if ROMs and MMPs are able to identify subjects among the three groups. Clinical variables (pain, disability, fear of movement, kinesiophobia, quality of life), MMPs and ROMs were obtained in 33 subjects with acute LBP, 33 with acute NP, and 33 healthy control subjects. Between-groups differences and explanatory models to discriminate groups depending on MMPs and ROMs were calculated. The results showed that cervical tone was higher in patients with acute NP than in controls, while cervical decrement was higher in both spinal pain groups. Patients with acute NP showed reduced cervical flexion when compared to acute LBP and control groups, and also cervical rotation, but just against controls. Furthermore, lumbar flexion was reduced in patients with acute LBP when compared to those with acute NP. Cervical decrement was able to discriminate spinal pain individuals from controls in a multinominal regression (R2: Cox–Snell estimation = 0.533; Nagelkerke estimation = 0.600). Lumbar flexion differentiated patients with acute LBP and controls, whereas cervical flexion differentiated patients with acute NP and controls. This study supports a tendency of the affectation of other spinal regions when only one is affected.

Impact of load expectations on neuromuscular and postural strategies during a freestyle lifting task in individuals with and without chronic low back pain

Objective This study aimed to investigate how load expectations modulate neuromuscular and postural strategies in the anticipation of a freestyle lifting task with varying expected loads in individuals with and without chronic low back pain (cLBP). Methods Forty-seven participants, 28 with cLBP pain and 19 without, were recruited and completed a series of freestyle lifting trials (3 sets of box lifted for a total of 36 lifts). Verbal cues were used to modulate their expectations about the boxes’ weight: no expectation, lighter or heavier load expectations. Following each set, participants rated their perceived exertion on a visual analog scale. During the lifting protocol, kinematics (time to maximal flexion, angular velocity and joint angles), electromyography muscle activity (erector spinae and quadriceps) and center of pressure displacement were simultaneously recorded. Results Results showed that time to maximal knee flexion was modulated by load expectations in both groups (mean lighter load expectations = 1.15 ± 0.32 sec.; mean heavier load expectations = 1.06 ± 0.31 sec.). Results also showed a load expectations X group interaction for that time to maximal hip and lumbar flexion. Time to maximal hip flexion decreased with heavier load expectations (mean lighter load expectations = 1.20 ± 0.36; mean heavier load expectations = 1.16 ± 0.33) for cLBP only. Time to maximal lumbar flexion increased with heavier load expectation (mean lighter load expectations = 1.41 ± 0.27 sec.; mean lighter load expectations = 1.46 ± 0.29 sec.) for participants without LBP. However, no difference in lumbar, hip nor knee angles were observed between groups or conditions. Results highlighted significant load expectation effects for erector spinae electromyography activity, as lower muscle activations was observed for both groups with heavier load expectations (mean = 0.32 ± 0.15), compared to lighter load expectations (mean = 0.52 ± 0.27). Force plates analyses did not reveal any significant load expectation effects. Conclusion Present findings showed that load expectations modulate movement strategies and muscle activation similarly but not identically in individuals with chronic low back pain and healthy adults during freestyle lifting. Results of the present study partially differ from previous studies and suggest only minor differences in lifting strategies between healthy individuals and individuals with cLBP experiencing low level of pain and disability. More studies are needed to investigate the potential role of load expectations in the development and persistence of chronic low back pain.