Effects of anteriorly-loaded treadmill walking on dynamic gait stability in young adults

BackgroundAnteriorly-loaded walking is common in many occupations and may increase fall risk. Dynamic gait stability, defined by the Feasible Stability Region (FSR) theory, quantifies the kinematic relationship between the body’s center of mass (COM) and base of support (BOS). FSR-based dynamic gait stability has been used to evaluate the fall risk.Research questionHow does front load carriage affect dynamic gait stability, step length, and trunk angle among young adults during treadmill walking?MethodsIn this between-subject design study, 30 healthy young adults were evenly randomized into three load groups (0%, 10%, or 20% of body weight). Participants carried their assigned load while walking on a treadmill at a speed of 1.2 m/s. Body kinematics were collected during treadmill walking. Dynamic gait stability (the primary variable) was calculated for two gait events: touchdown and liftoff. Step length and trunk angle were measured as secondary variables. One-way analysis of variance was conducted to detect any group-related differences for all variables. Post-hoc analysis with Bonferroni correction was performed when main group differences were found.ResultsNo significant differences but medium to large effect sizes were found between groups for dynamic gait stability at touchdown (p = 0.194, η² = 0.114) and liftoff (p = 0.122, η² = 0.139). Trunk angle significantly increased (indicating backward lean) with the front load at touchdown (p < 0.001, η² = 0.648) and liftoff (p < 0.001, η² = 0.543). No significant between-group difference was found related to the step length (p = 0.344, η² = 0.076).SignificanceCarrying a front load during walking significantly alters the trunk orientation and may change the COM-BOS kinematic relationship and, therefore, fall risk. The findings could inform the design of future studies focusing on the impact of anterior load carriage on fall risk during different locomotion.     

Lokalrezidive von Weichteilsarkomen an Extremitäten und Rumpf

Soft tissue sarcomas (STS) tend to recur locally. In a series of 140 patients operated on during the past two decades with STS of the extremities and trunk, prognostic factors influencing local recurrence were determined. Statistical significance was evaluated for the quality of surgical resection (P<0.001), regional positive lymph nodes (P=0.03), and adjuvant radiotherapy (P=0.01) [for resection without wide margins (R1) and low-grade (G3) tumors]. In 1988, the surgical procedure was standardized. After 1987, local recurrence decreased significantly (P < 0.001). In subfascial tumors, local recurrence occurred far less in cases of compartmental resection than with wide excision. These data indicate that the course of patients with STS can be beneficially influenced by optimal therapy. Resection with wide margins in all three dimensions is the aim of sarcoma surgery. Postoperative radiation therapy is indicated in the case of R1 resection.

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Lokalrezidive von Weichteilsarkomen an Extremitäten und Rumpf

Zusammenfassung Weichteilsarkome neigen zur Ausbildung von Lokalrezidiven. In einer Studie von 140 Patienten der letzten 20 Jahre mit Sarkomen an Extremitäten und Rumpf wurde untersucht, welche Faktoren das Auftreten von Lokalrezidiven beeinflussen. Statistische Signifikanz ergab sick fur die Qualität der chirurgischen Re sektion (R) (p<0,001), den regionalen Lymphknotenstatus (p=0,03) sowie eine adjuvante Strahlentherapie (p=0,01) [bei marginal resezierten (RI), niedrig differenzierten (G3) Tumoren]. 1988 wurde das chirurgische Vorgehen standardisiert. In der Zeit danach traten signifikant weniger Rezidive auf als davor (p < 0,001). Bei subfaszialer Lage traten Rezidive nach Kompartmentresektion wesentlich seltener auf als nach weiter Resektion. Der Krankheitsverlauf von Weichteilsarkomen ist also durchaus therapeutisch beeinflußbar. Ein dreidimensional weiter Sicherheitsabstand ist das entscheidende Therapieziel, eine Bestrahlung in R1-Situationen indiziert.

     

强化躯干核心肌群对脑卒中患者躯干控制平衡步行及日常生活能力的康复效果

目的探讨躯干核心肌群训练的强度对脑卒中患者躯干控制、平衡步行及日常生活能力的康复效果。方法选择2017年4月至2018年3月在华中科技大学同济医学院附属协和医院康复医学科住院治疗的90例脑卒中偏瘫患者为研究对象,按照随机数字表法将患者分为A、B、C组,每组各30例,3组患者均在常规治疗基础上联合不同强度的躯干核心肌群训练,其中A组每天训练1次,B组每天训练2次,C组每天训练3次,每次训练30 min,每周5天,共训练3个月。3组患者治疗1个月、2个月和3个月时采用躯干控制能力测试(TCT)、Berg平衡量表(BBS)评价躯干控制能力,采用步行功能评级(FAC)评定平衡步行功能、采用日常生活能力(MBI)评定日常生活能力。比较3组患者上述评分差异。结果治疗前3组患者躯干控制能力、平衡步行功能和生活能力评分比较差异无统计学意义(P> 0. 05),3组患者治疗1个月、2个月、3个月后躯干控制、平衡步行和日常生活能力评分均逐渐提高,差异均有统计学意义(P均<0. 05);且在1～3个月期间躯干控制和平衡能力评分C组高于B组,B组高于A组,差异均有统计学意义(P均<0. 05),但3个月时差异无统计学意义(P> 0. 05)。3组患者步行和日常生活能力在1个月期间组间差异无统计学意义(P> 0. 05),但1个月后C组较B组,B组较A组均有统计学意义(P均<0. 05)。结论强化躯干核心肌力量可以显著提高患者躯干控制、平衡步行和日常生活能力,缩短康复时间。     

The potential of an automated system to identify the upper limb component of a controlled sitting posture

Full trunk control in sitting is demonstrated only when the head-trunk are aligned and upper limbs remain free of contact from mechanical support. These components represent a Controlled Kinetic Chain and can be evaluated in people with neuromotor disability using the Segmental Assessment of Trunk Control (SATCo) when a therapist provides manual trunk support at different segmental levels. However, the SATCo, as with other clinical assessments of control, is subjective. The SATCo was translated to objective rules relating the position of the hands and elbows to the head-trunk and then tested to determine the extent to which this automated objective method replicated the clinical judgement.Clinical evaluation used video to determine whether the upper limb was free of mechanical support while the objective evaluation used 3D motion capture of the trunk and upper limbs with a classification rule. The agreement between clinical and objective classification was calculated for three conditions of a distance-from-support-surface threshold parameter in five healthy adults and five children with cerebral palsy.The unfitted (zero-threshold values) method replicated the clinical judgement in part (68.26% ± 15.7, adults, 48.3% ± 33.9 children). The fitted (level-of-support determined) agreement showed that the process could be refined using trial specific parameters (88.32% ± 5.3 adults, 89.84% ± 10.2 children). The fixed-values agreement showed high values when using general group parameters (80.80% ± 3.1 adults, 74.31% ± 21.5 children).This objective classification of the upper limb component of trunk control largely captures the clinical evaluation. It provides the first stages in development of a clinically-friendly fully automated method.     

The reliability and validity of the measurement of lateral trunk motion in two-dimensional video analysis during unipodal functional screening tests in elite female athletes

ObjectiveTo investigate the reliability and validity of the measurement of lateral trunk motion (LTM) in two-dimensional (2D) video analysis of unipodal functional screening tests.DesignObservational study.SettingResearch laboratory.ParticipantsForty-three injury-free female athletes.Main outcome measuresKnee valgus (KV) and lateral trunk motion (LTM) angles were measured with a standard digital camera during the single leg squat and the single leg drop vertical jump (SLDVJ). Three-dimensional motion analysis was used during the SLDVJ to measure peak external knee abduction moment (pKAM). Intraclass correlation coefficients were calculated to assess the intra- and intertester reliability of the LTM angle. Correlations between 2D angles and pKAM were calculated for the SLDVJ.ResultsExcellent intraclass correlation coefficients for the LTM angle were found within (0.99–1.00) and between testers (0.98–0.99). The sum of KV and LTM was significantly correlated with the pKAM during the SLDVJ for the dominant (r = −0.36; p = 0.017) and non-dominant leg (r = −0.32; p = 0.034), while either angle alone was not.ConclusionsLTM can be measured with excellent intra- and intertester reliability. The combination of KV and LTM was moderately associated with pKAM and thus including LTM may aid assessment of movement quality and injury risk.     

Age-Related Ultrasound Changes in Muscle Quantity and Quality in Women

This study investigated the age-related changes in muscle quantity and quality in the trunk and limbs of women. A total of 128 females were divided into four age groups: young, middle-aged, young-old and old-old. Muscle thickness (MT) and echo intensity (EI) of the biceps brachii, quadriceps femoris, rectus abdominis, external oblique, internal oblique and transversus abdominis were measured using B-mode ultrasonography. The EIs of the biceps brachii, quadriceps femoris and transversus abdominis were significantly higher in the middle-aged group than in the young group; however, there were no significant differences in MT. Compared with the young group, all other groups had significant changes in both MT and EI of the rectus abdominis, external oblique and internal oblique muscles. Thus, qualitative changes in muscle may occur earlier than quantitative changes, and loss of muscle mass may occur earlier in the superficial abdominal muscles than in the other muscles.     

Relationship of Hip and Trunk Muscle Function with Single Leg Step-Down Performance: Implications for Return to Play Screening and Rehabilitation

ObjectivesEvaluate the relationship of hip and trunk muscle function with the Single Leg Step-Down test (SLSD).Study designLaboratory study.SettingBiomechanics Laboratory.Participants71 healthy participants with no history of anterior cruciate ligament (ACL) or lower extremity injury in the last 3 months completed this study (38 males, 33 females; mean 25.49 ± 0.62 years).Main outcomesHip abduction (HABD), external rotation (HER), and extension (HEXT) peak isometric force were measured. Trunk endurance was measured with plank (PL) and side plank (SPL) tests. SLSD repetitions in 60-s and dynamic knee valgus (VAL) were recorded.ResultsPL, SPL, HABD, HER, and HEXT were positively correlated with SLSD repetitions. PL (r = 0.598, p < 0.001) was most correlated with SLSD repetitions, and regression demonstrated that PL (p = 0.001, R² = 0.469) was a predictor of SLSD repetitions. VAL trended toward negative correlation with PL and SPL. Sex-specific differences were present, with PL, SPL, HABD, and HER showing stronger relationships with SLSD in females.ConclusionHip and trunk muscle function were positively correlated with SLSD performance, and these relationships were strongest in females. PL predicted performance on the SLSD. Further research is needed to investigate the utility of SLSD as a screening or return-to-play test for lower extremity conditions such as ACL injury and patellofemoral pain.     

Visual afference mediates head and trunk stability in vestibular hypofunction

Humans must maintain head and trunk stability while walking. The purpose of this study was to compare the kinematics of healthy controls and patients with vestibular hypofunction (VH) when walking and making head rotations of different frequencies in both light and dark conditions. We recruited eight individuals with VH and nine healthy control subjects to perform four tasks at their preferred gait speed, being normal walk, walking and making yaw head rotations at 1.5 Hz and 2 Hz, and walking in the dark and making yaw head rotations at 1.5 Hz. Linear kinematics as well as head, trunk, and pelvis angular velocities were captured using the Vicon motion analysis system (Vicon Motion Systems, Oxford, UK). We found no difference in walking velocities for any of the four walking conditions across groups. The lateral displacement of the center of mass was increased in VH patients. In the dark, patients had more head instability in pitch (larger amplitudes and velocities) even though they were walking and making active yaw head rotations. Patients also had a smaller relative phase angle (mean 3.50 ± standard deviation 2.13°) than controls (mean 10.31 ± standard deviation 2.70°) (p < 0.01). Our data suggest that patients with VH have difficulty walking with a straight trajectory when turning their head. Additionally, patients with VH have an abnormal excursion of spontaneous pitch head rotation while walking and making active yaw head turns, which is dependent on vision. Rehabilitation for these patients should consider applying unique head rotation frequencies when training gait with head turns as well as alternating their exposure to light.     

Activation amplitude patterns do not change for back muscles but are altered for abdominal muscles between dominant and non-dominant hands during one-handed lifts

It is assumed when lifting with the dominant hand that the relationship between contralateral and ipsilateral trunk muscle responses are similar to when lifting with the non-dominant hand. The purpose of this study was to quantify trunk muscle activation amplitude patterns during right- and left-handed lifts. Surface electromyography (EMG) and kinematic variables were recorded from 29 healthy subjects. Minimal trunk and pelvis motion was observed. Three principal patterns accounted for 95% of the variation in the EMG data indicating minimal variation in the pattern. Significant differences in scores captured different recruitment strategies for reach and hand. Selective and differential recruitment of back sites characterized lifts at greater distances from the body, whereas co-activation between internal oblique and back sites characterized lifts closer to the body. While the results showed no handedness effect for back muscles, the external oblique responded differently between right- and left-handed lifts. Specific recruitment strategies were used to account for subtle changes in reach and asymmetrical demands.