Forward Trunk Flexion Research Articles

Gait compensations, pain, and functional performance during the six minute walk test in individuals with unilateral hip osteoarthritis

BackgroundIndividuals with unilateral hip osteoarthritis walk with kinematic and spatiotemporal compensations compared to healthy individuals. Our purpose was to determine associations between gait, pain, and functional performance during the six-minute walk test. MethodsTrunk and hip kinematics and spatiotemporal gait outcomes were recorded from individuals with unilateral hip osteoarthritis using inertial sensors (Xsens Technologies). Pain was collected prior to and at the end of the six-minute walk test. Paired t-tests were conducted to evaluate gait between limbs and between the first and final minutes of walking. Correlations were conducted between gait, pain, and six-minute walk test performance. FindingsNineteen participants (8 females, age: 63 ± 5 yrs., BMI: 29.0 ± 4.5 kg/m2) completed the study. Between-limb differences in hip flexion, hip extension, and trunk forward flexion peak angles were observed during the six-minute walk test (P < .05). Participants demonstrated an increase in trunk forward flexion of the osteoarthritis side (t = −2.34, P = .031) and a bilateral decrease in stride length (osteoarthritis limb: t = 2.98, P = .008, non- osteoarthritis limb: t = 3.17, P = .006) from the first to the final minute of walking. Greater pain was associated with greater osteoarthritis limb hip extension (first minute: r = −0.506, P = .027, final minute: r = −0.53, P = .020) and greater hip abduction (r = 0.46, P = .046) during the final minute of walking. InterpretationsGait compensations increase throughout the six-minute walk test, and pain associates with hip kinematics during the six-minute walk test. Wearable technology may allow for more accurate clinical movement assessments.

Visual Deprivation's Impact on Dynamic Posture Control of Trunk: A Comprehensive Sensing Information Analysis of Neurophysiological Mechanisms.

Visual information affects static postural control, but how it affects dynamic postural control still needs to be fully understood. This study investigated the effect of proprioception weighting, influenced by the presence or absence of visual information, on dynamic posture control during voluntary trunk movements. We recorded trunk movement angle and angular velocity, center of pressure (COP), electromyographic, and electroencephalography signals from 35 healthy young adults performing a standing trunk flexion-extension task under two conditions (Vision and No-Vision). A random forest analysis identified the 10 most important variables for classifying the conditions, followed by a Wilcoxon signed-rank test. The results showed lower maximum forward COP displacement and trunk flexion angle, and faster maximum flexion angular velocity in the No-Vision condition. Additionally, the alpha/beta ratio of the POz during the switch phase was higher in the No-Vision condition. These findings suggest that visual deprivation affects cognitive- and sensory-integration-related brain regions during movement phases, indicating that sensory re-weighting due to visual deprivation impacts motor control. The effects of visual deprivation on motor control may be used for evaluation and therapeutic interventions in the future.

The effect of subjective postural vertical on forward flexed posture in Parkinson's disease

BackgroundWe developed a novel method to measure the angle of subjective postural vertical (SPV) and showed that the SPV may be related to the exacerbation of the forward flexed posture. ObjectivesThe present study prospectively tested the effects of the subjective postural vertical on the exacerbation of the forward flexion of trunk (FFT) through long-term observation of Parkinson's disease patients. MethodsEvaluation of the posture included measuring FFT, the angle of lateral flexion of trunk, and the angle at the position that the patient subjectively perceived as the vertical position at a stationary upright position immediately after standing up at the time of initial observation, 6 months later, and 1 year later. ResultsThe SPV angles worsened significantly at 6 months and 1 year compared to the first measurements (9.3 ± 6.7° vs. 10.8 ± 8.2° and 10.6 ± 7.8°, P < 0.05), and the FFT angles worsened significantly at one year compared to the first measurements (11.1 ± 8.1° vs. 12.2 ± 8.8°, P = 0.004). Furthermore, using a hierarchical multiple regression model, the difference in SPV from the first visit to the first half year was considered a factor contributing to annual FFT change (P = 0.002). ConclusionsThis longitudinal study of a large number of cases suggested that changes in SPV may precede changes in FFT.

Lumbo-Pelvic Rhythm Monitoring Using Wearable Technology with Sensory Biofeedback: A Systematic Review.

As an essential lower-back movement pattern, lumbo-pelvic rhythm (LPR) during forward trunk flexion and backward return has been investigated on a large scale. It has been suggested that abnormalities in lumbo-pelvic coordination are related to the risk of developing low back disorders. However, considerable differences in the approaches used to monitor LPR make it challenging to integrate findings from those investigations for future research. Therefore, the aim of this systematic review was to summarize the use of wearable technology for kinematic measurement with sensory biofeedback for LPR monitoring by assessing these technologies' specific capabilities and biofeedback capacities and exploring their practical viability based on sensor outcomes. The review was developed following the PRISMA guidelines, and the risk of bias was analyzed using the PREDro and STROBE scales. PubMed, Web of Science, Scopus, and IEEEXPLORE databases were searched for relevant studies, initially returning a total of 528 articles. Finally, we included eight articles featuring wearable devices with audio or vibration biofeedback. Differences in protocols and limitations were also observed. This novel study presents a review of wearable tracking devices for LPR motion-mediated biofeedback for the purpose of correcting lower back posture. More research is needed to determine the long-term effectiveness of these devices, as well as their most appropriate corresponding methodologies.

Cardiovascular response of students to physical exertion using the 'Trunk Flexion Test'

Background and Study Aim. Multiple factors affect the health condition of students. In this regard, a key preventative measure is observing the students' level of physical preparedness. The aim of the study is to assess the cardiovascular system response of students to physical exercise using the 'Trunk Flexion Test'. Material and Methods. This study included 77 students from the physical education faculties of three universities in Ukraine, comprising 34 males and 43 females. The cardiovascular system's response was gauged using the 'Trunk Forward Flexion Test'. Data on participants were compiled through Google Form. Statistical evaluation was conducted using PyCharm CE and Python programming libraries. ANOVA was utilized to determine the differences in cardiovascular responses among students, and Pearson's correlation coefficient explored the relationship between body mass index and cardiovascular function. Results. Research findings show gender-based disparities in cardiovascular system responses (CVSR). Women outperformed men in achieving 'Excellent' ratings. Women also led in 'Good' and 'Average' evaluations, while men were more likely to be in 'Undesirable' and 'Hazardous' categories. Differences were noted in body mass index. The proportion of students with normal weight differed by university. The prevalence of overweight varied among universities. The occurrence of 'Underweight' and 'Obese' also varied by university. An elevation in body mass index was correlated with a decline in CVSR in men. Conclusions. Variations in CVSR highlight the importance of implementing wellness initiatives and encouraging students to enhance their physical activity levels.

Effect of istradefylline on postural abnormalities in patients with Parkinson's disease: An association study of baseline postural angle measurements with changes in Unified Dystonia Rating Scale total score

In our previous study, istradefylline treatment in patients with Parkinson's disease (PD) improved postural abnormalities (PAs), as seen from a decrease in the mean Unified Dystonia Rating Scale (UDRS) total score from week 0 to week 24. A subgroup analysis based on baseline clinical characteristics investigated the association between improvement in the UDRS total score and istradefylline treatment. However, the association between an objective assessment of PAs and improvement in the UDRS total score is unclear. This ad hoc analysis investigated the association between improvement in the UDRS total score after istradefylline treatment and baseline trunk and neck angles, objective assessments of PAs, measured from patients' photographs taken in the previous study. The patients (n = 31) were stratified into groups based on the trunk forward flexion angle (TFFA), trunk lateral flexion angle (TLFA), and neck flexion angle (NFA) values at baseline. From week 0 to week 24, significant improvements in the UDRS total score were found in median percent change (−8.33% [interquartile range: −43.97, 0.00], P = 0.039) in patients with equal to or above the median TFFA values, and in median change (−‍1.50 [−9.25, 0.00], P = 0.015) and median percent change (−13.33% [−50.47, 0.00], P = 0.009) in patients with equal to or above the median TLFA values. Patients with more advanced PAs showed more consistent improvements in the UDRS total score with istradefylline. Baseline TFFA and TLFA values, which are objective values, may be useful to assess the istradefylline effectiveness in patients with PD and PAs.

Lower-Limb Range of Motion Predicts Sagittal Spinal Misalignments in Children: A Case-Control Study

The main objective of this study was to determine lower-limb range of motion (ROM) as a risk factor associated with sagittal spinal misalignments in children. Two hundred and one children (10.9 ± 0.7 years old) from five different primary schools were recruited for this retrospective case—control study. Anthropometric variables, sagittal spinal alignment in habitual everyday postures, and lower-limb ROM, such as ankle dorsiflexion with the knee flexed (ADF-KF), hip extension with the knee relaxed (HE), and hip flexion with the knee extended (HF-KE) were measured. Multivariate and univariate analyses revealed differences between the means of HE and HF-KE ROM, and the thoracic and lumbar curves (p ≤ 0.034; η2 ≥ 0.052). The HE (p ≤ 0.028; OR ≥ 1.066) predicted sagittal thoracic misalignment in the slump sitting (SSP) and relaxed standing (RSP) postures in males and the sagittal lumbar misalignment in the RSP in female children; while HF-KE (p ≤ 0.006; OR ≥ 1.089) predicted sagittal thoracic misalignment in the maximum trunk forward flexion posture (MTFP) and sagittal lumbar misalignment in SSP and MTFP in males. In this study, the reference values for restricted HE and HF-KE were significantly associated with sagittal spinal misalignment in male children but not for the ankle ROM. Physical education teachers should include stretching exercises in the ISQUIOS programme to increase the extensibility of the iliopsoas (HE) and hamstrings (HF-KE) and prevent sagittal spinal misalignments in habitual everyday postures.

Descriptive trunk kinematics in healthy collegiate women's soccer players indicate trunk center of mass is laterally positioned prior to decelerating and cutting

ObjectivesTrunk kinematics can contribute to lower extremity biomechanical risk factors for anterior cruciate ligament (ACL) injury. However, normative trunk kinematics during unilateral athletic tasks in a large population of “healthy” (no history of ACL injury and no known future ACL injury) women's soccer players have not been well-described. This study's purposes were to describe trunk kinematics in a population of 37 healthy collegiate women's soccer players completing a step-down, a deceleration, and a 90° cut, and to provide a reference for normative values. MethodsA cross-sectional cohort of 37 female soccer players were analysed for this study. Trunk forward flexion and lateral flexion were measured relative to the pelvis, and trunk centre of mass position was measured relative to the proximal tibia. Trunk kinematics were characterized by individual values at key events during the tasks and time-series curves normalized to 100% of the time. ResultsParticipants demonstrated increasing trunk forward flexion with increasing knee flexion angle, small amounts of increasing ipsilateral trunk flexion with increasing peak knee abduction moment, and trunk centre of mass position that moved medially during the deceleration and cut tasks. Additionally, participants demonstrated peak trunk lateral flexion angles milliseconds before peak knee flexion angle. ConclusionThis study provides a reference for identifying aberrant trunk mechanics that may increase the risk for non-contact ACL injury. Level of evidenceLevel II.

Machine learning and statistical prediction of fastball velocity with biomechanical predictors

In recent years, one of the most important factors for success among baseball pitchers is fastball velocity. The purpose of this study was to (1) to develop statistical and machine learning models of fastball velocity, (2) to identify the strongest predictors of fastball velocity, and (3) to compare the models' prediction performances. Three dimensional biomechanical analyses were performed on high school (n = 165) and college (n = 62) baseball pitchers. A total of 16 kinetic and kinematic predictors from the entire pitching sequence were included in regression and machine learning models. All models were internally validated through ten-fold cross-validation. Model performance was evaluated through root mean square error (RMSE) and calibration with 95% confidence intervals. Gradient boosting machines demonstrated the best prediction performance [RMSE: 0.34; Calibration: 1.00 (95% CI: 0.999, 1.001)], while regression demonstrated the greatest prediction error [RMSE: 2.49; Calibration: 1.00 (95% CI: 0.85, 1.15)]. Maximum elbow extension velocity (relative influence: 19.3%), maximum humeral rotation velocity (9.6%), maximum lead leg ground reaction force resultant (9.1%), trunk forward flexion at release (7.9%), time difference of maximum pelvis rotation velocity and maximum trunk rotation velocity (7.8%) demonstrated the greatest influence on pitch velocity. Gradient boosting machines demonstrated better calibration and reduced RMSE compared to regression. The influence of lead leg ground reaction force resultant and trunk and arm kinematics on pitch velocity demonstrates the interdependent relationship of the entire kinetic chain during the pitching motion. Coaches, players, and performance professionals should focus on the identified metrics when designing pitch velocity improvement programs.

Effects of capacitive and resistive electric transfer therapy on pain and lumbar muscle stiffness and activity in patients with chronic low back pain.

[Purpose] In this study, we investigated the therapeutic effects of capacitive and resistive electric transfer therapy in patients with chronic low back pain. [Participants and Methods] The study included 24 patients with chronic low back pain (12 patients each in the intervention and sham groups). Pain intensity, superficial and deep lumbar multifidus stiffness and maximum forward trunk flexion and associated activation level of the iliocostalis (thoracic and lumbar component) and lumbar multifidus muscles were measured. [Results] Post-intervention pain intensity and muscle stiffness were significantly lower than pre-intervention measurements in the intervention group. However, no between-group difference was observed in the muscle activation level at the end-point of standing trunk flexion. [Conclusion] Our findings highlight a significant therapeutic benefit of capacitive and resistive electric transfer therapy in patients with chronic low back pain and muscle stiffness.

Physical demands of overhead crane operation

Recent studies have suggested that ergonomic factors may contribute to risks experienced by overhead crane operators. However, there are few studies that provide a comprehensive overview of the physical demands of overhead crane operation. This study aimed to provide this information by quantifying muscular, postural, and upper limb movement demands of overhead crane operation including examination of muscle activation and trunk posture by task. Trunk posture, upper limb movement demands and muscle activation in the trunk and upper limbs were quantified for seven overhead crane operators. Trunk posture was quantified using trunk angle and joystick motion requirements were determined using camera data. Muscle activation was measured bilaterally using surface EMG for the upper trapezii, anterior deltoids, posterior deltoids, biceps brachii, triceps brachii, flexor carpi radialis and erector spinae. Lastly, joystick force requirements were assessed using a spring scale. High upper limb and trunk muscle loading were observed when compared to joystick use in other heavy machinery, in part due to the forward, trunk-flexed position required to adequately view the workspace, and the increased force requirements of the joysticks. Joystick input force requirements were 9–31 N for the right-hand joystick and 11–40 N for the left-hand joystick. Operators maintained a forward trunk flexion (>20°) for all subtasks which suggests that trunk posture might play a role in sustained trunk muscle activation. Results suggest that the primary issue with overhead crane cab operation is upper limb and trunk muscle loading. Results confirm the need to investigate muscle load reduction strategies such as camera systems to help reduce the need for trunk flexion. Other design modification suggestions include reducing the joystick input force and displacement requirements coupled with potentially distributing the machine functions more evenly across the right and left controllers.

Subject-Specific Spino-Pelvic Models Reliably Measure Spinal Kinematics During Seated Forward Bending in Adult Spinal Deformity.

Image-based subject-specific models and simulations are recently being introduced to complement current state-of-the-art mostly static insights of the adult spinal deformity (ASD) pathology and improve the often poor surgical outcomes. Although the accuracy of a recently developed subject-specific modeling and simulation framework has already been quantified, its reliability to perform marker-driven kinematic analyses has not yet been investigated. The aim of this work was to evaluate the reliability of this subject-specific framework to measure spine kinematics in ASD patients, in terms of 1) the overall test-retest repeatability; 2) the inter-operator agreement of spine kinematic estimates; and, 3) the uncertainty of those spine kinematics to operator-dependent parameters of the framework. To evaluate the overall repeatability 1], four ASD subjects and one control subject participated in a test-retest study with a 2-week interval. At both time instances, subject-specific spino-pelvic models were created by one operator to simulate a recorded forward trunk flexion motion. Next, to evaluate inter-operator agreement 2], three trained operators each created a model for three ASD subjects to simulate the same forward trunk flexion motion. Intraclass correlation coefficients (ICC’s) of the range of motion (ROM) of conventional spino-pelvic parameters [lumbar lordosis (LL), sagittal vertical axis (SVA), thoracic kyphosis (TK), pelvic tilt (PT), T1-and T9-spino-pelvic inclination (T1/T9-SPI)] were used to evaluate kinematic reliability 1] and inter-operator agreement 2]. Lastly, a Monte-Carlo probabilistic simulation was used to evaluate the uncertainty of the intervertebral joint kinematics to operator variability in the framework, for three ASD subjects 3]. LL, SVA, and T1/T9-SPI had an excellent test-retest reliability for the ROM, while TK and PT did not. Inter-operator agreement was excellent, with ICC values higher than test-retest reliability. These results indicate that operator-induced uncertainty has a limited impact on kinematic simulations of spine flexion, while test-retest reliability has a much higher variability. The definition of the intervertebral joints in the framework was identified as the most sensitive operator-dependent parameter. Nevertheless, intervertebral joint estimations had small mean 90% confidence intervals (1.04°–1.75°). This work will contribute to understanding the limitations of kinematic simulations in ASD patients, thus leading to a better evaluation of future hypotheses.

Understanding regional activation of thoraco-lumbar muscles in chronic low back pain and its relationship to clinically relevant domains

BackgroundAltered regional activation of the lumbar extensors has been previously observed in individuals with low back pain (LBP) performing high-effort and fatiguing tasks. It is currently unknown whether similar alterations can be observed during low-effort functional tasks. Similarly, previous studies did not investigate whether side differences in regional activation are present in individuals with LBP. Finally, there is limited evidence of whether the extent of the alteration of regional activation is associated with clinical factors. Therefore, the aim of this study was to investigate whether individuals with LBP exhibit asymmetric regional activation of the thoraco-lumbar extensor muscles during functional tasks, and if the extent of neuromuscular control alteration is associated with clinical and psychosocial outcome domains.Methods21 participants with and 21 without LBP performed five functional tasks (gait, sit-to-stand, forward trunk flexion, shoulder flexion and anterior pelvic tilt). The spatial distribution of activation of the thoraco-lumbar extensor muscles was assessed bilaterally using high-density electromyography. For each side, the distribution of electromyographic (EMG) amplitude was characterized in terms of intensity, location and size. Indices of asymmetry were calculated from these features and comparisons between groups and tasks were performed using ANOVA. The features that significantly differed between groups were correlated with self-reported measures of pain intensity and other outcome domains.ResultsIndices of asymmetry did not differ between participants with and without LBP (p > 0.11). The cranio-caudal location of the activation differed between tasks (p < 0.05), but not between groups (p = 0.64). Participants with LBP showed reduced EMG amplitude during anterior pelvic tilt and loading response phase during gait (both p < 0.05). Pearson correlation revealed that greater pain intensity was associated with lower EMG amplitude for both tasks (R<-0.5, p < 0.05).ConclusionsDespite clear differences between tasks, individuals with and without LBP exhibited similar distributions of EMG amplitude during low-effort functional activities, both within and between sides. However, individuals with LBP demonstrated lower activation of the thoraco-lumbar muscles during gait and anterior pelvic tilt, especially those reporting higher pain intensity. These results have implications in the development or refinement of assessment and intervention strategies focusing on motor control in patients with chronic LBP.

The Science and Biomechanics of Long-Toss

Overhead throwing is a particularly violent motion that requires a complex sequence of timed muscle activations to efficiently transfer energy up the kinetic chain to throw a ball. Long-toss has long been utilized as a means of increasing shoulder range of motion, strength, and endurance, as well as an important component of rehabilitation in interval throwing programs. The purpose of this review is to assess the current literature on the science and biomechanics of long-toss. While long-toss is ubiquitously utilized in throwing programs for pitchers of all ages, the definition of long-toss, as well as its primary function in a throwing program, is debated. Throwing biomechanics in long-toss differ from that of mound pitching, although much of the variation is determined by the type of long-toss: shorter distance and on a line versus maximum distance and not on a line. Biomechanical factors including the kinematic changes of increased maximum glenohumeral external rotation, increased maximum elbow flexion, decreased trunk forward flexion at front foot contact, kinetic changes of increased shoulder internal rotation torque, increased elbow varus torque, and increased elbow extension velocity can occur with maximum distance long-toss throwing. Long-toss is a highly variable training supplement that is used in throwing programs at all levels of baseball competition. Current literature has demonstrated a number of kinetic and kinematic changes in the throwing arm and throwing motion related to increasing long-toss distances. However, the exact benefits of long-toss are difficult to quantify due to the numerous definitions and various utilizations of long-toss.

라이프케어증진을 위한 흉·복부 호흡패턴교정이 요추부 불안정성자들의 몸통 전방 굴곡 동작에 미치는 영향

본 연구는 호흡 패턴 교정 후, 호흡 동안 흉·복부 둘레 선 세 곳의 운동성(TAMs) 변화와 몸통 전방 굴곡 동안 흉추(TSM) 및 요추부 운동성(LSM)의 변화를 조사하기 위해 수행되었다. 요추부 불안정성이 있는 30명의 대상자들을 15명의 호흡패턴 교정운동 그룹과 15명의 요추부 안정화운동그룹으로 나누어, 한 세션 당 40분 운동, 총 18 세션을 6주 동안 적용하였다. 연구 결과, 호흡패턴교정 그룹은 안정화 운동 그룹에 비해 모든 TAMs과 TSM 이 유의하게 더 증가한 것으로 나타났고 LSM은 더 유의한 감소를 보였다(p<.001). 호흡패턴교정은 전체 TAM(안정호흡: r= .868, 노력성호흡: r= .870) 및 TSM(r= .672)과는 높은 양의 상관관계를, LSM(r= -.420)과는 음의 상관관계를 나타내었다. 본 연구 결과를 기초로, 요추부 불안정성자의 호흡패턴교정이 흉·복부 둘레 선의 상대적 운동성 개선을 통해 흉추와 늑골관절의 운동성을 촉진하여 몸통 전방 굴곡 시 요추부 굴곡 운동성을 감소시킬 수 있다고 제안한다.

Effect of changes in the lumbar posture in lifting on trunk muscle and spinal loads: A combined in vivo, musculoskeletal, and finite element model study

Irrespective of the lifting technique (squat or stoop), the lumbar spine posture (more kyphotic versus more lordotic) adopted during lifting activities is an important parameter affecting the active-passive spinal load distribution. The advantages in either posture while lifting remains, however, a matter of debate. To comprehensively investigate the role on the trunk biomechanics of changes in the lumbar posture (lordotic, free or kyphotic) during forward trunk flexion, validated musculoskeletal and finite element models, driven by in vivo kinematics data, were used to estimate detailed internal tissue stresses-forces in and load-sharing among various joint active-passive tissues. Findings indicated that the lordotic posture, as compared to the kyphotic one, resulted in marked increases in back global muscle activities (~14–19%), overall segmental compression (~7.5–46.1%) and shear (~5.4–47.5%) forces, and L5-S1 facet joint forces (by up to 80 N). At the L5-S1 level, the lordotic lumbar posture caused considerable decreases in the moment resisted by passive structures (spine and musculature, ~14–27%), negligible reductions in the maximum disc fiber strains (by ~0.4–4.7%) and small increases in intradiscal pressure (~1.8–3.4%). Collectively and with due consideration of the risk of fatigue and viscoelastic creep especially under repetitive lifts, current results support a free posture (in between the extreme kyphotic and lordotic postures) with moderate contributions from both active and passive structures during lifting activities involving trunk forward flexion.

Upper camptocormia in Parkinson's disease: Neurophysiological and imaging findings of both central and peripheral pathophysiological mechanisms

BackgroundCamptocormia is a disabling complication of Parkinson's disease (PD), but its pathophysiology is poorly elucidated. Depending on the fulcrum of forward trunk flexion, two subtypes have been defined, upper (UCC) and lower camptocormia, the former being much more frequent. The aim of the study was to explore possible pathophysiological mechanisms of PD-related UCC. MethodsTen PD patients with UCC (UCC-PD) and ten PD patients without camptocormia (NoUCC-PD) underwent simultaneous electromyography (EMG) of thoracic paraspinal (TPS), obliquus externus abdominis (OEA), rectus abdominis (RA), and iliopsoas (IP) muscles during relaxed standing (both groups) and trunk realignment (UCC-PD group). Quantitative EMG and magnetic resonance imaging (MRI) of TPS muscles were also performed. ResultsUCC-PD patients showed hyperactivity of TPS and OEA muscles in quiet stance. During voluntary trunk extension, hyperactivity of OEA muscles persisted, thus revealing a co-contraction of flexor and extensor trunk muscles. Motor unit potentials (MUP) of TPS muscles showed shorter duration (p = 0.005) and lower amplitude (p = 0.004) in UCC-PD than in NoUCC-PD patients. MRI did not detect significant between-group differences in the cross-sectional area and fat fraction of TPS muscles, although the latter was higher in the UCC-PD than in the NoUCC-PD group at all thoracic levels. ConclusionOur findings suggest that hyperactivity of OEA might sustain UCC in PD. Concurrent mild myopathic changes in TPS muscles in PD with UCC may be secondary to muscle disuse but nevertheless may contribute to abnormal trunk posture.

The influence of sagittal trunk posture on the magnitude and rate of patellofemoral joint stress during stair ascent in asymptomatic females

Background: Excessive patellofemoral joint stress (PFJS) is thought to be a contributory factor to patellofemoral pain (PFP). Thus, treatment strategies that minimize PFJS rate and magnitude during painful activities like stair ascent may be useful for optimizing outcomes for PFP patients. Sagittal plane trunk posture has been shown to influence PFJS during running although it is unknown if a similar relationship exists during stair ascent. Research Question: Does altering sagittal plane trunk posture affect PFJS rate and/or magnitude during stair ascent? Methods: Twenty asymptomatic females (23.4±2.5 yr; height: 164.4±7.9 cm; mass: 63.0±12.2 kg) performed 5 stair ascent trials (96 steps/min) during 3 conditions: self-selected trunk (SS), flexed trunk (FLX), and extended trunk (EXT). Three-dimensional kinematics (200 Hz) and ground reaction forces (2000 Hz) were collected during each trial. A previously described mathematical model was used to calculate PFJS that included subject-specific and non-subject-specific model inputs. Dependent variables included sagittal plane trunk angle, and the rates and magnitudes of PFJS, patellofemoral joint reaction force (PFJRF), and PFJ contact area during the stance phase of stair ascent. Results: Compared to SS, peak PFJS decreased during FLX (mean difference (MD)=2.6 MPa; p<0.001; 95%CI=2.2 to 2.9; effect size (ES)=5.2) and increased during EXT (MD=-3.3 MPa; p<0.001; 95%CI=-3.9 to -2.6; ES=-3.4). Similarly, PFJS rate decreased during FLX (MD=17.8 MPa/sec; p<0.001; 95%CI=13.6 to 21.9; ES=3.6) and increased during EXT (MD=-14 MPa/sec; 95%CI=-19.4 to -8.7; p<0.001; ES=-2.2). Significance: Sagittal plane trunk posture influences PFJS rate and magnitude during stair ascent in asymptomatic females. Increasing and decreasing forward trunk flexion resulted in decreased and increased PFJS respectively. Future studies should examine the effects of these movement strategy modifications on pain and function in patients with PFP.

Deterioration of postural deformity in Parkinson’s disease patients with punding and hobbyism

This study aimed to examine whether worsening of postural deformities is seen in Parkinson’s disease (PD) patients who exhibit the behavioral disorders punding or hobbyism (P-H), which involve maintaining the same poor posture. The subjects were 80 patients with PD (aged 73.1 ± 8.8 years; duration of disease, 6.4 ± 5.5 years). Using the Japanese-language version of the Questionnaire for Impulsive-Compulsive Disorders in Parkinson’s Disease (J-QUIP), a group with P-H alone (P-H only group) and a group without impulsive-compulsive behaviors (non-ICB group) were compared with respect to the angles of forward and lateral trunk flexion while standing at rest. The group with ICBs (ICB group) identified by the J-QUIP consisted of 36 patients (45.0%). Of these, 25 (31.3%) were in the P-H only group. The non-ICB group, who were negative on all items of the J-QUIP, consisted of 44 patients (55.0%). Significantly higher values were seen in the P-H only group compared with non-ICB group for the angle of forward flexion of the trunk (FFT angle, p = 0.04), Unified Parkinson’s Disease Rating Scale (UPDRS) part II score (p = 0.002), and UPDRS total score (p = 0.007). The FFT angle was increased and activities of daily living decreased in PD patients with P-H.

Four-week trunk-specific exercise program decreases forward trunk flexion in Parkinson's disease: A single-blinded, randomized controlled trial

IntroductionPathological forward trunk flexion is a disabling and drug-refractory motor complication of Parkinson's disease (PD) leading to imbalance, pain, and fall-related injuries. Since it might be reversible, early and multidisciplinary management is emphasised. The primary aim was to compare the effects of a four-week trunk-specific rehabilitation program on the severity of the forward trunk flexion. The secondary aim was to compare the training effects on the motor impairments, dynamic and static balance, pain, falls, and quality of life. Methods37 patients with PD (H&Y ≤ 4) and forward trunk flexion were randomized in the experimental (n = 19) or control group (n = 18). The former consisted of active self-correction exercises with visual and proprioceptive feedback, passive and active trunk stabilization exercises and functional tasks. The latter consisted of joint mobilization, muscle strengthening and stretching, gait and balance exercises. Protocols lasted 4 weeks (60 min/day, 5 days/week). Before, after, and at 1-month follow-up, a blinded examiner evaluated patients using primary and secondary outcomes. The primary outcome was the forward trunk flexion severity (degree). Secondary outcomes were the UPDRS III, dynamic and static balance, pain falls, and quality of life assessment. ResultsThe experimental group reported a significantly greater reduction in forward trunk flexion than the control group from T0 to both T1 (p = 0.003) and T2 (p = 0.004). The improvements in dynamic and static balance were significantly greater for the experimental group than the control group from T0 to T2 (p = 0.017 and 0.004, respectively). Comparable effects were reported on the other outcomes. Pre-treatment forward trunk flexion values were highly correlated to post-treatment trunk deviation changes. ConclusionThe four-week trunk-specific rehabilitation training decreased the forward trunk flexion severity and increased postural control in patients with PD. NCT03741959.