Instrument assisted soft tissue mobilization (IASTM) versus stretching: A comparison in effectiveness on hip active range of motion,muscle torque and power in people with hamstring tightness

BackgroundInstrument-assisted soft tissue mobilization (IASTM) is a new technique that has been known to be effective in reducing muscle tightness in athletics. However, little is known about its effect on the range of motion, muscle power, and torque compared to manual stretching among non-athletics. Thus, the study was aimed to compare the effectiveness between IASTM and manual stretching in improving hip flexion active range of motion (ROM), muscle torque and power on hamstring muscle complex (HMC) tightness in one session.MethodTwenty-three young male college students with unilateral hamstring tightness measured via straight leg raising (SLR) test (<65°) were randomly assigned to one of two groups. Twelve participants received the application of IASTM (group 1), and eleven received manual stretching (group 2). Hip flexion active ROM was measured via goniometer, the torque & power of the hamstring muscle were measured using Humac isokinetic dynamometer, before and after both interventions. (ISRCTN17693345).ResultsThere was no significant difference in the improvement of hip flexion active ROM (69.6 ± 6.6 vs 72.5 ± 7.9, p = .34), HMC torque (63.7 ± 14.5 vs 53.2 ± 16.3, p = .14), and HMC power (47.8 ± 11.8 vs 40.9 ± 16.3, p = .34) between group 1 and group 2 respectively. When a comparison was made within each group, significant improvements in hip active flexion ROM was found in both groups (p's < .001), and HMC power was significantly improved in group 1 (p = .04) but not in group 2.ConclusionThe current study findings demonstrate that IASTM was as effective as manual stretching in improving hip flexion active ROM, muscle torque and power among non-athletic people with HMC tightness.     

Comparison of Shoulder and Back Muscle Activation in Caregivers According to Various Handle Heights

[Purpose] This study aims to improve the safety for caregivers and avoid musculoskeletal diseases by examining the shoulder and trunk muscle activity depending on wheelchair handle height as the caregiver provides propulsion to a wheelchair for wheelchair-bound patients. [Subjects] The participants were caregivers who met the criteria for this study (n=30). [Methods] To determine the activity of the shoulder and trunk muscles of caregivers depending on the handle height, the muscle activity was measured as a wheelchair was being pushed under three height conditions. [Results] According to the study results, the deltoid middle fiber, serratus anterior muscle, rhomboid muscle, and erector spinalis of lumbar part showed significantly low muscle activity at a height that produced an elbow joint flexion angle of 30°. Caregivers are highly likely to develop musculoskeletal disease if the handle height is excessively low. In addition, the burden on the shoulder and back muscles can be reduced at heights that lead to flexion of 30°. [Conclusions] As a caregiver pushes a wheelchair, the handle height has a close relationship with the burden on the shoulder and back muscles. If the handle height is excessively low, the caregiver is highly likely to develop musculoskeletal disease.Key words: Caregiver, Muscle activation, Wheelchair handle height     

Lumbar axial rotation kinematics in men with non-specific chronic low back pain

BackgroundLumbar flexion, coupled with rotation, is a dominant factor in the etiology and exacerbation of low back pain. Yet, no study has examined its kinematics in patients with non-specific chronic low back pain (NSCLBP). The aim of the study was to evaluate the lumbar rotation kinematics in neutral standing and with full flexion in men with NSCLBP.MethodsROM, average velocity, maximum velocity and maximal acceleration of lumbar rotation in neutral standing and with full flexion were measured using an industrial lumbar motion monitor in 50 men (25 with NSCLBP and 25 controls). VAS and Rolland Morris questionnaire were also included.FindingsAll examined kinematical parameters were significantly lower in men with NSCLBP compared with controls (↓ROM = 29%–45%; ↓AV = 40%–68%; ↓MV = 25%–50%; ↓MA = 20%–37%). Left rotation manifested smaller kinematic values (except for MA) than right rotation (Δ ROM = 35%; Δ AV = 66%; Δ MV = 19%) in NSCLBP. Most kinematical parameters significantly decreased from neutral standing to standing with flexion (right rotation: ↓ROM = 43%–45%, ↓AV = 38%–45%, ↓MV = 24%–27%, ↓MA for the NSCLBP group = 21%; left rotation: ↓ROM = 25%–38%, ↓AV in the control group: =34%, ↓MV in the control group: =23%, ↓MA in the control group = 25%). No correlations were found between all measured kinematical parameters, VAS and RMQ total score in the NSCLBP group.InterpretationThe kinematic parameters of lumbar rotation were reduced in men with NSCLBP compared with controls both in neutral standing and with fully forward bending.Most lumbar rotation kinematics decreased from neutral standing to standing with flexion.     

Effect of ankle dorsiflexion on displacement and strain in the tibial nerve and biceps femoris muscle at the posterior knee during the straight leg raise: Investigation of specificity of nerve movement

BackgroundA structural differentiation maneuver has been proposed to differentiate between muscle and nerve involvement during the straight leg raise test. However, to date, the mechanical specificity of this maneuver for the tibial nerve at the posterior knee has not been tested. The aim of this study was to investigate the specificity of ankle dorsiflexion as a differentiation maneuver between the tibial nerve and the biceps femoris muscle at the posterior knee during the straight leg raise in cadavers.MethodsA cross-sectional study was carried out. In fresh frozen cadavers, with microstrain devices and Vernier calipers, strain and excursion in the tibial nerve and distal biceps femoris muscle were measured during ankle dorsiflexion at 0°, 30°, 60° and 90° of hip flexion of the straight leg raise.FindingsAnkle dorsiflexion resulted in significant distal excursion and increased strain in the tibial nerve (p < 0.05) whilst the muscle was not affected by the dorsiflexion (p > 0.05) at all hip flexion angles.InterpretationAnkle dorsiflexion was mechanically specific between the tibial nerve and biceps femoris during the straight leg raise. This study adds to evidence that, in certain circumstances, dorsiflexion may be used in differentiation of nerve and muscle disorders in the posterior knee.     

Characteristics of thoracic and lumbar movements during gait in lumbar spinal stenosis patients before and after decompression surgery

BackgroundAlthough gait analysis has been previously conducted for lumbar spinal stenosis patients, the vertebral segmental movements, such as of the thoracic and lumbar regions, and whether the spinal movement during gait changes after decompression surgery remain unclear.MethodsTen patients with lumbar spinal stenosis and 10 healthy controls participated. Clinical outcomes were assessed using the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire and Visual Analogue Scale. Spinal kinematic data of the participants during gait were acquired using a three-dimensional motion analysis system. The trunk (whole spine), thoracic, and lumbar flexion and pelvic tilting values were calculated. Spinal kinematic data and clinical outcomes were collected preoperatively and 1 month postoperatively for the patients.FindingsCompared to that observed preoperatively, the clinical outcomes significantly improved at 1 month postoperatively. In the standing position, the preoperative lumbar extension of the patients was significantly smaller than that of the controls. Moreover, during gait, the lumbar flexion relative to the standing position of the patients was smaller than that of the controls preoperatively, and increased at 1 month postoperatively. The sum of the thoracic and lumbar flexion values during gait negatively correlated with the score for leg pain.InterpretationThe epidural pressure of lumbar spinal stenosis patients is known to be higher than that of normal subjects during gait, and to decrease during walking with lumbar flexion. Preoperatively, smaller thoracic and lumbar flexion movements during gait relative to the standing position cannot decrease epidural pressure; as a result, severe leg pain might be induced.     

The effect of manual therapy and neuroplasticity education on chronic low back pain: a randomized clinical trial

Objective: To determine if a neuroplasticity educational explanation for a manual therapy technique will produce a different outcome compared to a traditional mechanical explanation.

Methods: Sixty-two patients with chronic low back pain (CLBP) were recruited for the study. Following consent, demographic data were obtained as well as pain ratings for low back pain (LBP) and leg pain (Numeric Pain Rating Scale), disability (Oswestry Disability Index), fear-avoidance (Fear-Avoidance-Beliefs Questionnaire), forward flexion (fingertips-to-floor), and straight leg raise (SLR) (inclinometer). Patients were then randomly allocated to receive one of two explanations (neuroplasticity or mechanical), a manual therapy technique to their lumbar spine, followed by post-intervention measurements of LBP, leg pain, forward flexion, and SLR.

Results: Sixty-two patients (female 35 [56.5%]), with a mean age of 60.1 years and mean duration of 9.26 years of CLBP participated in the study. There were no statistically significant interactions for LBP (p = .325), leg pain (p = .172), and trunk flexion (p = .818) between the groups, but SLR showed a significant difference in favor of the neuroplasticity explanation (p = .041). Additionally, the neuroplasticity group were 7.2 times (95% confidence interval = 1.8–28.6) more likely to improve beyond the MDC on the SLR than participants in the mechanical group.

Discussion: The results of this study show that a neuroplasticity explanation, compared to a traditional biomechanical explanation, resulted in a measureable difference in SLR in patients with CLBP when receiving manual therapy. Future studies need to explore if the increase in SLR correlated to changes in cortical maps of the low back.     

Asymmetry in children with unilateral cerebral palsy during sit-to-stand movement: Cross-sectional,repeated-measures and comparative study

BackgroundWe aimed to compare motor strategies adopted by children with unilateral Cerebral Palsy and typically developing children during the performance of sit-to-stand.MethodsEleven children with unilateral cerebral palsy and 20 typically developing children were evaluated. Kinematic and kinetic analysis of the sit-to-stand movement was performed. Three seat heights were evaluated: neutral (90° of hip-knee-ankle flexion), elevated to 120% of the neutral height, and lowered to 80% of the neutral height. As outcome variables, we considered sit-to-stand duration (temporal); initial, final and maximal sagittal angles and range of motion of trunk, pelvis, hip, knee, and ankle (kinematics); the peak of vertical ground reaction force (kinetics), and asymmetric index. Effect size is represented by η₂p.FindingsWe found that for the lowered seat, all groups presented increased flexion of lower limbs and trunk to initiate sit-to-stand (p≤0.012; η₂p = 0.41–0.84), increased peak flexion of trunk, hip and knee (p≤0.01; η₂p = 0.39–0.88), increased range of motion of knee and trunk (p≤0.01; η₂p = 0.45–0.85) and the duration of sit-to-stand (p≤0.05 η₂p = 0.23–0.56). Children with unilateral cerebral palsy presented increased posterior pelvic tilt (p≤0.01) and decreased hip flexion of both lower limbs (p≤0.01) for all seat heights and moved their non-affected limb backward in the lowered seat (p≤0.01). Asymmetry was observed for the final and the maximal angles of the ankle in neutral and lowered seats in unilateral cerebral palsy (asymmetry index = 3.3–5.8%).InterpretationThe lowered seat height led to adaptive motor strategies in children with unilateral cerebral palsy, which should be considered in clinical practice.     

Interaction Between Thoracic Movement and Lumbar Spine Muscle Activation Patterns in Young Adults Asymptomatic for Low Back Pain: A Cross-Sectional Study

ObjectiveThe purpose of this study was to investigate the interaction between thoracic movement and lumbar muscle co-contraction when the lumbar spine was held in a relatively neutral posture.MethodsThirty young adults, asymptomatic for back pain, performed 10 trials of upright standing, maximum trunk range of motion, and thoracic movement tasks while lumbar muscle activation was measured. Lumbar co-contraction was calculated, compared between tasks, and correlated to thoracic angles.ResultsMovement tasks typically exhibited greater co-contraction than upright standing. Co-contraction in the lumbar musculature was 67%, 45%, and 55% greater than upright standing for thoracic flex, thoracic bend, and thoracic twist, respectively. Generally, the thoracic movement task demonstrated greater co-contraction than the maximum task in the same direction. Co-contraction was also correlated to thoracic angles in each movement direction.ConclusionTasks with thoracic movement and a neutral lumbar spine posture resulted in increases in co-contraction within the lumbar musculature compared with quiet standing and maximum trunk range-of-motion tasks. Findings indicated an interaction between the 2 spine regions, suggesting that thoracic posture should be accounted for during the investigation of lumbar spine mechanics.     

How Different Modes of Child Delivery Influence Abdominal Muscle Activities in the Active Straight Leg Raise

[Purpose] The purpose of this study was to examine the activities of the abdominal muscles of women who had experienced vaginal delivery in comparison with those who had experienced Cesarean childbirth. [Subjects and Methods] A total of 14 subjects (7 vaginal delivery, 7 Cesarean section) performed an active straight leg raise to 20 cm above the ground, and we measured the activities of the internal oblique abdominal muscle, the external oblique abdominal muscle, and the rectus abdominal muscle on both sides using electromyography. The effort required to raise the leg was scored on a Likert scale. Then, the subjects conducted maximum isometric contraction for hip joint flexion with the leg raised at 20 cm, and maximum torque and abdominal muscle activities were measured using electromyography. [Results] During the active straight leg raise, abdominal muscle activities were higher in the Cesarean section subjects. The Likert scale did not show a significant difference. The activities of the abdominal muscles and the maximum torque of the hip joint flexion at maximum isometric contraction were higher in the vaginal delivery subjects. [Conclusion] The abdominal muscles of Cesarean section subjects showed greater recruitment for maintaining pelvic stability during the active straight leg raising, but were relatively weaker when powerful force was required. Therefore, we consider that more abdominal muscle training is necessary for maintaining pelvic stability of Cesarean section subjects.Key words: Modes of delivery, Abdominal muscle, Active straight leg raising     

经皮椎间孔镜技术对腰椎间盘突出症患者的疗效及对机体氧化应激水平的影响

目的:探讨经皮椎间孔镜技术在腰椎间盘突出症患者中的应用效果及对其一氧化氮(NO)、过氧化物岐化酶(SOD)水平的影响。方法:选择2017年1月至2020年6月诊治为腰椎间盘突出症的136例患者,按随机数字表法分为2组,各68例。对照组采用椎板开窗手术治疗,观察组采用经皮椎间孔镜技术治疗,术后1个月评估疗效。比较两组患者的Oswestry功能障碍指数(ODI)、疼痛视觉模拟评分(VAS)、JOA腰椎评分(JOA)、直腿抬高角度、NO、SOD、炎性因子及并发症发生率。结果:观察组治疗后1个月ODI、VAS评分低于对照组(P0.05),JOA及直腿抬高角度高于对照组(P0.05)。观察组治疗后1个月NO、SOD水平升高,但治疗后3个月低于对照组(P0.05),治疗后1个月IL-6、hs-CRP水平低于对照组(P0.05)。观察组与对照组术后感染、切口愈合不良、感觉功能改变、血肿及脏器损伤发生率差异无统计意义。结论:与椎板开窗手术相比,经皮椎间孔镜技术能更好地改善腰椎间盘突出症患者的腰椎功能、减轻疼痛、降低氧化应激反应和炎性因子水平,手术安全性较高,值得推广应用。     

Three-Dimensional Spinal Position With and Without Manual Distraction Load Increases Spinal Height

ObjectiveThe purpose of this study was to investigate if spinal height increases using 3-dimensional (3-D) spinal position with and without manual distraction load and to assess the correlation between spine height changes and degrees of trunk rotation.MethodsFifty-six participants were randomly placed in one of two groups: (1) 3-D spinal position with manual distraction load, and (2) without manual distraction load. Spinal height was measured before and after the interventions using a stadiometer. For the statistical analysis, we used a 2 (Loading status: pre- versus post-intervention height) X 2 (3-D spinal position: with versus without manual distraction load) repeated measures Analysis of Variance (ANOVA) was used to identify significant interaction and main effects. Paired t-tests were used to calculate differences in spinal height changes between the two interventions. Pearson correlation coefficient was used to measure correlations between changes in spinal heights and degrees of trunk rotation.ResultsMean spinal height increase with 3-D spinal position with and without manual distraction load was 6.30 mm (±6.22) and 5.69 mm (±4.13), respectively. No significant interaction effect was present between loading status and 3-D spinal position but a significant main effect in loading status was. Paired t-tests revealed significant differences in spinal heights between pre-and post-3-D spinal position with and without manual distraction load. No significant correlation was measured between trunk rotation and spinal height changes.Conclusion3-D spinal position with or without distraction load increased spinal height. This suggests that 3-D spinal positioning without manual distraction could be used in home settings to help maintain intervertebral disc (IVD) health.     

超声检查先天性马蹄内翻足患儿跟腱

目的 探讨超声检查在先天性马蹄内翻足(CCF)跟腱检查中的应用价值。方法 收集33例CCF患儿,按照病变累及范围分为单侧CCF组(18例)和双侧CCF组(15例);选取同期20名健康婴儿作为对照组。行双足跟腱超声检查,测量自然位、背屈位、跖屈位下的跟腱长度(AL),计算3组自然位与背屈位、自然位与跖屈位、背屈位与跖屈位AL的差值,并进行统计学分析。结果 超声发现全部CCF患足跟腱形态及AL异常,自然位时跟腱不平直,中部不同程度凹陷,长度较健足短。双侧CCF组患足与对照组健足、单侧CCF组患足与对侧健足自然位时AL及自然位与背屈位、自然位与跖屈位、背屈位与跖屈位AL的差值均有统计学意义(P均<0.05),背屈位、跖屈位时AL的差异无统计学意义(P>0.05)。结论 超声可直观显示CCF患儿不同体位下跟腱形态及AL改变,动态观察并评估患足背屈、跖屈活动异常。     

DEEP NECK FLEXORS IMPACT RECTUS ABDOMINIS MUSCLE ACTIVITY DURING ACTIVE STRAIGHT LEG RAISING

Background:Active straight leg raising (ASLR) is commonly performed to test fundamental movement competency. Head control or positioning can affect the abdominal muscle activity during movements.Purpose:To investigate whether abdominal muscle activity differs when the head is extended or when deep neck flexor (DNF) muscles are selectively activated during the ASLR.Study Design:Cross-sectionalMethods:Participants were included based on the following criteria: 1) age>17 years; 2) no spinal or lower extremity pain in the prior month; 3) the vertical line of the malleolus in an elevated the lower limb resides below the knee joint line of a non-moving lower limb during ASLR and above during a passive straight leg raising in each lower limb; and 4) no history of diagnosed spinal deformities or central nervous system disorders. Participants with > 39% reference voluntary contraction in the sternocleidomastoid muscle during the craniocervical flexion test (CCFT) of 24 mmHg target were excluded from the analyses. Right ASLR was repeated in each of the following three head conditions in a random order: 1) neutral head position, 2) head extended by 25 °, and 3) CCFT maintained with a 24 mmHg target. Among the three head conditions, the relative latency for the onset of the right rectus femoris (RF) muscle during the right ASLR and the muscle activity amplitude for 50ms were compared after the onset of RF muscular activity in the following muscles: left rectus abdominis (RA), bilateral external obliques, bilateral internal obliques, and left gluteus maximus muscles.Results:Data from 31 participants (21 women and 10 men, mean age=22.5 years) were analyzed. The relative latency of the left RA (Hedges’ g = 0.39, p=.038) was higher in the CCFT condition (mean±SD=112.1ms±86.0ms) than that in the neutral head condition (82.9ms±58.6ms). However, no difference (all p>.05) was observed in other measures between the groups.Conclusion:In people with impaired movement competency in ASLR, head extension did not alter the abdominal muscle activities in ASLR. However, selective activation of the DNF muscles delayed the onset of RA muscle activity during the ASLR.Level of Evidence:4     

The active straight leg raising test (ASLR) in pregnant women: differences in muscle activity and force between patients and healthy subjects

Pregnancy-related low back and pelvic pain (PLBP) is a frequent complication of pregnancy. Although pathological mechanisms underlying PLBP are obscure, dysfunction of the sacroiliac joints (SI-joints) seems to play an important role. A cross-sectional study was performed on 24 pregnant women with and without PLBP. The objective was to determine muscle activation patterns of trunk and leg muscles during the active straight leg raising test (ASLR) and static hip flexion, and to determine maximal hip flexion force at 0 and 20 cm leg raise height. Moreover, the effort to raise the leg was scored. The measurements resulted in several significant differences between the patients and healthy controls; among others (a) patients scored subjectively more effort during ASLR, (b) at both 0 and 20 cm leg raise height patients had less hip flexion force, and (c) patients developed more muscle activity during ASLR. Since pregnant women with PLBP developed a higher muscle activity during ASLR with a significantly lower output at 0 and 20 cm than healthy pregnant women, it could be proposed that the ASLR demonstrates a disturbed load transfer across the SI-joints in this population.     

The influence of the crutch setup on stability and weight-bearing parameters in post total hip replacement surgery patients during quiet standing

Purpose: The purpose of this study is to evaluate the influence of the crutch setup on standing, in post total hip replacement (THR) surgery patients.

Materials and methods: Thirty patients after THR were randomly assigned to walking with the elbow flexed (EF) or elbow straight (ES) crutch setup. Subjects were asked to stand on a force platform in a comfortable position with the crutch positioned on the unaffected side, facing forward for 10?seconds. Centre of pressure total path and maximal excursion were evaluated in both medio-lateral and anterior–posterior planes. Difference in the asymmetry of left/right acromial height, measured with and without the crutch, was calculated (ACdiff). Percentage of body weight borne by the crutch (Fcr), symmetry (SIload) between operated and healthy limbs loading during the trial, together with shoulder forces and moments were measured.

Results: No significant differences between the two groups (p?>?.05) were found for stability parameters. ACdiff, Fcr and shoulder load increased significantly (p?Conclusions: The present study showed that the ES setup reduced the force borne by the crutch, the load on the shoulder joint and it minimized postural and loading asymmetries when compared to EF setup. Conversely, postural stability was not influenced by the crutch setup.

• Implications for Rehabilitation

• Static posture and weight-bearing parameters are influenced by crutch setup during quiet standing.

• Crutch setup does not influence postural stability.

• Adjusting the crutch according to the elbow straight setup reduces the force borne by the crutch and the asymmetry in lower limbs loading.

• Forces and moments at the shoulder joint were reduced for the elbow straight setup group.

     

Effect of backrest height on wheelchair propulsion biomechanics for level and uphill conditions

Yang Y-S, Koontz AM, Yeh S-J, Chang J-J. Effect of backrest height on wheelchair propulsion biomechanics for level and uphill conditions.ObjectiveTo evaluate the effect of backrest height on wheelchair propulsion kinematics and kinetics.DesignAn intervention study with repeated measures.SettingUniversity laboratory.ParticipantsConvenience sample included manual wheelchair users (N=36; 26 men and 10 women) with spinal cord injuries ranging from T8 to L2.InterventionParticipants propelled on a motor-driven treadmill for 2 conditions (level and slope of 3°) at a constant speed of 0.9m/s while using in turn a sling backrest fixed at 40.6cm (16in) high (high backrest) and a lower height set at 50% trunk length (low backrest).Main Outcome MeasuresCadence, stroke angle, peak shoulder extension angle, shoulder flexion/extension range of motion, and mechanical effective force.ResultsPushing with the low backrest height enabled greater range of shoulder motion (P<.01), increased stroke angle (P<.01), push time (P<.01), and reduced cadence (P=.01) regardless of whether the treadmill was level or sloped.ConclusionsA lower cadence can be achieved when pushing with a lower backrest, which decreases the risk of developing upper-limb overuse related injuries. However, postural support, comfort, and other activities of daily living must also be considered when selecting a backrest height for active, long-term wheelchair users. The improvements found when using the low backrest were found regardless of slope type. Pushing uphill demanded significantly higher resultant and tangential force, torque, mechanical effective force, and cadence.     

Compensatory strategies of body-powered prosthesis users reveal primary reliance on trunk motion and relation to skill level

BackgroundWhile body-powered prostheses are commonly used, the compensatory strategies required to operate body-powered devices are not well understood. Kinematic assessment in addition to standard clinical tests can give a comprehensive evaluation of prosthesis user function and skill. This study investigated the movement compensations of body-powered prosthesis users and determined whether a correlation is present between compensatory strategies and skill level, as measured by a standard clinical test.MethodsFive transradial body-powered prosthesis users completed two standardized upper limb tasks. A 12-camera motion capture system was used to obtain three-dimensional angular kinematics for eight degrees of freedom at the trunk, shoulder, and elbow. Range of motion was compared to a normative dataset. Pearson's correlation was used to assess the relationship between the Activities Measure for Upper Limb Amputees and range of motion for each degree of freedom.FindingsParticipants displayed a statistically significant (P < .05) increase in range of motion at the trunk for both tasks. Shoulder flexion/extension range of motion was significantly reduced (P < .05) compared to normative values, but shoulder abduction/adduction range of motion did not show a consistent difference compared to norms. Skill level was correlated with range of motion for specific degrees of freedom at the trunk, shoulder, and elbow.InterpretationBody-powered prosthesis users compensated with trunk movement and showed reduced motion for shoulder flexion/extension, with relatively normal shoulder abduction/adduction. Skill level was correlated with angular kinematic strategies, which may allow targeting of specific therapeutic interventions for reducing compensatory movements.     

Comparison of lumbar repositioning error according to different lumbar angles in a flexion pattern (FP) subgroup of patients with non-specific chronic low back pain

[Purpose] This study determined the change in lumbar position sense according to lumbar angles in a flexion pattern (FP) subgroup of patients with non-specific chronic low back pain (NCSLBP). [Subjects] Thirteen subjects with FP low back pain participated. [Methods] The lumbar repositioning error (RE) of subjects was measured between a neutral starting position and re-position phases at three angles, in sitting and standing upright positions. [Results] Lumbar RE was significantly greater during lumbar flexion at a 30° angle in the sitting position than in the other tasks. [Conclusion] In the flexion-related subgroup, the lumbar RE measurement may be a more sensitive evaluation method using a lumbar flexion angle of 30° while in the sitting position, compared with other angles in sitting or standing positions.Key words: Flexion pattern, Low back pain, Repositioning error     

Predictors of shoulder pain in manual wheelchair users

BackgroundManual wheelchair users rely on their upper limbs to provide independent mobility, which leads to high muscular demand on their upper extremities and often results in shoulder pain and injury. However, the specific causes of shoulder pain are unknown. Previous work has shown that decreased shoulder muscle strength is predictive of shoulder pain onset, and others have analyzed joint kinematics and kinetics, propulsion technique and intra-individual variability for their relation to shoulder pathology. The purpose of this study was to determine in a longitudinal setting whether there are specific biomechanical measures that predict shoulder pain development in manual wheelchair users.MethodsAll participants were asymptomatic for shoulder pain and categorized into pain and no pain groups based on assessments at 18 and 36 months later. Shoulder strength, handrim and joint kinetics, kinematics, spatiotemporal measures, intra-individual standard deviations and coefficients of variation were evaluated as predictors of shoulder pain.FindingsIndividuals who developed shoulder pain had weaker shoulder adductor muscles, higher positive shoulder joint work during recovery, and less trunk flexion than those who did not develop pain. In addition, relative intra-individual variability was a better predictor of shoulder pain than absolute variability, however future work is needed to determine when increased versus decreased variability is more favorable for preventing shoulder pain.InterpretationThese predictors may provide insight into how to improve rehabilitation training and outcomes for manual wheelchair users and ultimately decrease their likelihood of developing shoulder pain and injuries.     

Comparative analysis of low-back loading on chiropractors using various workstation table heights and performing various tasks

BACKGROUND: There is epidemiologic evidence that chiropractors are a high-risk group for low-back disorders. However, to date there are no known biomechanical studies to determine whether their workstations may be a contributing factor. OBJECTIVE: To investigate whether chiropractors' workstation table height or the tasks they perform make them susceptible to low-back strain. As well as investigating low-back strain, a screening was performed to determine whether chiropractors' upper extremities were at risk for undue strain as workstation table height was varied. Study Design: Experimental pilot study. SETTING: A university ergonomic laboratory. METHODS: An adjustable manipulation table was set at 3 different heights: 465 mm, 665 mm and 845 mm.Each of the 7 volunteer chiropractors were fitted with a triaxial electrogoniometer and were videotaped and photographed for analysis while performing spinal manipulation to the cervical, thoracic, and lumbar spine of a volunteer patient at each workstation table height. Two biomechanical models, one static and one dynamic, were used to record the dependent variables. A screening of various upper extremity variables was also performed with the static model. RESULTS: For the subjects under study, a significant difference was found for the variables maximum sagittal flexion, disk compression force, and ligament strain as table height was varied. For the lumbar and thoracic manipulation tasks, the medium table height (655 mm) was found to create the least low-back strain. For the cervical manipulation task, the high table height (845 mm) was found to be the least straining on the low-back. The low height table (465 mm) was the most straining for all tasks. Upper extremities were not significantly affected by changes to table height. Significant differences were found for the task performed for axial rotational velocity, disk compression force, ligament strain, maximum sagittal flexion, dominant (right) elbow moment, and dominant (right) shoulder moment variables. There was no significant interaction between table height and task performed. CONCLUSION: Workstation table height was found to have a significant effect on low-back load of subjects under study. The results of this study demonstrate an overall unacceptably high amount of sagittal flexion, ligament strain, and disk compression force on the chiropractor subjects in the tasks performed.