Preoperative physical activity is associated with prognosis in patients with esophageal cancer undergoing thoracoscopic-laparoscopic esophagectomy after neoadjuvant chemotherapy.

OBJECTIVE: This study examined the association between a single preoperative physiotherapy session during neoadjuvant chemotherapy and physical function and that between preoperative physical activity and prognosis. METHODS: In this retrospective, single-center, observational study, we evaluated data from 234 patients scheduled for neoadjuvant chemotherapy and thoracoscopic-laparoscopic esophagectomy who underwent a single preoperative physiotherapy session. The five-repetition sit-to-stand test was performed before and after neoadjuvant chemotherapy. After neoadjuvant chemotherapy, patients were classified into high- and low-physical activity groups based on preoperative physical activity. To examine the association between preoperative physiotherapy and changes in physical function, a multivariate regression analysis was performed. The Cox proportional hazards model was used to investigate the association between preoperative physical activity and overall survival. RESULTS: The median percentage change in the five-repetition sit-to-stand test score was - 3.36%. In the multivariate regression analysis, the regression coefficient of the constant term was - 23.93 (95% confidence interval - 45.31 to - 2.56; P = 0.028). Low physical activity was significantly associated with overall survival after adjustment for confounding factors (P = 0.040). CONCLUSIONS: This study demonstrated that a single preoperative physiotherapy session during neoadjuvant chemotherapy improves physical function, and preoperative physical activity is significantly associated with prognosis.

Factors associated with physical function in patients after surgery for soft tissue sarcoma in the thigh.

PURPOSE: This study aimed to examine the validity of the timed up and go test (TUGT), which is a representative, objective, and functional assessment that can evaluate walking speed, strength, and balance, and determine the significant factors associated with physical dysfunction in the early postoperative period in patients with soft tissue sarcomas (STSs). METHODS: This retrospective, single-center, observational study conducted at the National Cancer Center Hospital included 54 patients with STSs in the thigh who underwent surgery. The Musculoskeletal Tumor Society (MSTS) score, which subjectively evaluates the affected limb, was evaluated at discharge, and TUGT was performed preoperatively and at discharge. Higher scores indicated good limb function in the MSTS score and poor performance in the TUGT. Spearman's correlation analysis was performed to identify the relationship between the MSTS score and TUGT. A receiver operating characteristic curve was used to calculate the cut-off value of the change in pre- and postoperative TUGT for an MSTS score of ≥ 80%. To examine the significant factors associated with physical dysfunction, multivariate regression analysis was performed using the change in pre- and postoperative TUGT as the dependent variable. RESULTS: Postoperative TUGT and the change in pre- and postoperative TUGT were significantly associated with the MSTS score. The cut-off value for the change in pre- and postoperative TUGT for acceptable affected lower-limb function was 3.7 s. Furthermore, quadriceps muscle resection was significantly associated with the change in pre- and postoperative TUGT in the early postoperative period. CONCLUSIONS: TUGT could be a useful objective evaluation tool for postoperative patients with STSs. The cut-off value for the change in TUGT can be used to monitor postoperative recovery. If recovery is prolonged, a rehabilitation program can be designed according to the severity of the functional impairment in muscle strength, balance, or gait. In addition, sufficient information should be obtained regarding the presence or absence of quadriceps resection, which has a significant impact on postoperative performance.

Evaluation of clinical factors associated with early postoperative physical function and lower extremity functional impairment in patients with soft tissue sarcoma.

PURPOSE: This study aimed to investigate the relationship between various clinical factors and physical function in the early postoperative period in patients with soft tissue sarcomas (STSs) by subjective and objective evaluations. MATERIALS AND METHODS: The 90 patients enrolled in this study were classified into five groups according to tumor location: retroperitoneal, gluteal, groin, thigh, and lower leg. The Musculoskeletal Tumor Society (MSTS) score was evaluated at discharge; the timed up-and-go test (TUGT) was performed preoperatively and at discharge. Group comparisons by tumor location were performed. To identify significant factors associated with physical dysfunction, multivariate analysis was performed using an MSTS score of <80% and a change in pre and postoperative TUGT score. RESULTS: There were no significant differences between the tumor location and physical function. The change in pre- and postoperative TUGT scores was significantly associated with an MSTS score of <80%. Quadriceps and tibialis anterior muscle resections were significantly associated with the change in pre- and post-operative TUGT scores. CONCLUSIONS: The quadriceps and tibialis anterior muscles may affect physical dysfunction after surgery for STSs. Early postoperative rehabilitation should include the identification of resected muscles and functional improvement of residual muscles, possibly with orthotic support for knee extension and ankle dorsiflexion.

Surgical intervention for soft tissue sarcomas often leads to functional impairment of lower extremities.The Musculoskeletal Tumor Society scoring system and timed up-and-go test (TUGT) can be used as subjective and objective evaluations of physical function in patients with tumors in the lower extremities.The quadriceps and tibialis anterior muscle resections were significantly associated with change in the pre- and postoperative TUGT scores in the early postoperative period in patients with soft tissue sarcomas (STSs).For early postoperative rehabilitation of STSs, identification of resected muscles and functional improvement of residual muscles, possibly with orthotic support for knee extension and ankle dorsiflexion are recommended.

Progress in muscle strength of the reconstructed knee and quality of life of the patient after knee rotationplasty: A case report.

Knee rotationplasty (KRP) is a function-preserving surgery that serves as an alternative to above-knee amputation in patients diagnosed with malignant bone and soft tissue tumors around the knee joint. However, the short-term progress of the reconstructed knee in terms of muscle strength is unclear after KRP. This case report describes the progress of a 37-year-old man diagnosed with synovial sarcoma in the distal femur, 1 year after undergoing KRP. Changes in muscle strength of the reconstructed knee and physical function are reported. Physical therapy was started on postoperative day 1 after the KRP, and mobilization proceeded step-by-step with sitting, wheelchair transfer, and crutch walking. Active and passive range-of-motion exercises of the reconstructed knee were started on postoperative day 5. The isometric reconstructed knee extension strength, 10-m walk test, timed up and go test, Musculoskeletal Tumor Society score, Toronto Extremity Salvage Score, and quality of life (QOL) were evaluated. One month postoperatively, muscle strength had increased, and at 6 and 12 months postoperatively, isometric knee extension strength and physical function had improved. Furthermore, activities of daily living and QOL gradually improved over the course of the 12 months. Our case shows the previously unknown course of reconstructed knee muscle strength in the early post-KRP period, with corresponding improvements in physical function, activities of daily living, and QOL.

The evaluation of the association between preoperative sarcopenia and postoperative pneumonia and factors for preoperative sarcopenia in patients undergoing thoracoscopic-laparoscopic esophagectomy for esophageal cancer.

PURPOSE: This study identified the relationship between postoperative pneumonia and preoperative sarcopenia as well as the factors for preoperative sarcopenia in patients with esophageal cancer. METHODS: In this retrospective, single-center, observational study, we evaluated the data of 274 patients who were scheduled for thoracoscopic-laparoscopic esophagectomy. Sarcopenia was defined using the skeletal muscle index, handgrip strength, and gait speed. The physical activity and nutritional status were evaluated. A multivariate logistic regression analysis was performed to confirm the association between sarcopenia and postoperative pneumonia and identify sarcopenia-related factors. A Spearman's correlation analysis was used to identify the relationship between physical activity and nutritional status. RESULTS: Age, male sex, sarcopenia, and postoperative recurrent laryngeal nerve palsy were significantly associated with postoperative pneumonia. Age, male sex, physical activity, and nutritional status were significantly associated with preoperative sarcopenia. There was a significant correlation between physical activity and nutritional status. CONCLUSIONS: Preoperative sarcopenia was confirmed to be a predictor of postoperative pneumonia. Furthermore, age, sex, physical activity, and nutritional status were significantly associated with preoperative sarcopenia. Physical activity and nutritional status are closely associated with each other in patients with esophageal cancer. A multidisciplinary approach to preoperative sarcopenia, taking exercise and nutrition into account, is recommended.

Characteristics of Trunk Compensation Movements during Walking in People with Bilateral Transtibial Amputation: A Cross-sectional Study.

Objectives: The gait characteristics of people with bilateral transtibial amputation are not well understood. This study aimed to clarify changes in trunk lateral bending and the trunk flexion angle during walking in people with bilateral transtibial amputation. Methods: In this cross-sectional study, four participants with bilateral transtibial amputation who could walk without assistance (BTTA group) and ten able-bodied participants (control group) were recruited. The range of motion of trunk lateral bending, the trunk flexion angle, and other gait parameters during comfortable-speed and maximum-speed walking were measured using a three-dimensional motion analysis system and force plates. These parameters were compared between the amputees and the controls. Results: During maximum-speed walking, the BTTA group walked slower with a smaller trunk flexion angle (median, 1.75° vs. 4.79°, P=0.036) and greater double leg support time (0.18 vs. 0.12, P=0.008) when compared with the control group. The other parameters during maximum-speed walking were not significantly different between the two groups. During comfortable-speed walking, none of the parameters were significantly different between the two groups. Conclusions: Compensatory trunk flexion angle decreases markedly during maximum-speed walking in people with bilateral transtibial amputation. People with bilateral transtibial amputation may be changing the trunk flexion angle to walk faster. When evaluating gait compensation for people with bilateral transtibial amputation, trunk flexion angle may be an important index and maximum-speed walking is needed to detect the change in trunk flexion angle.

Cancer Rehabilitation Provided by Designated Cancer Hospitals in Japan: The Current State of Outpatient Setting and Coordination after Discharge.

Objectives: The aim of the present study was to clarify the current state of outpatient cancer rehabilitation and coordination systems provided by designated cancer hospitals in Japan. Methods: A questionnaire was sent to 427 designated cancer hospitals in Japan to investigate the status of outpatient cancer rehabilitation and whether it was sufficiently conducted. The status of regional coordination with post-discharge rehabilitation facilities was surveyed. Results: Responses were received from 235/427 facilities (55.0%). Outpatient cancer rehabilitation was implemented in 92 (39.1% of responding facilities), and of these facilities, 83.7% answered that the provision of rehabilitation was insufficient. The reasons were ineligibility for reimbursement of medical fees, a lack of human resources, a lack of awareness of the need, and a lack of education. Regional coordination was conducted by 39.1% of responding facilities, yet a regional alliance path had been established in only 9.8% of centers. The absence of coordination was associated with large facility size, the absence of physiatrists, and few rehabilitation professionals who had completed the training program; an insufficient framework for regional coordination was also given as a reason. Conclusions: To provide adequate outpatient cancer rehabilitation, sufficient human resources, the reimbursement of medical fees in the outpatient setting, and education and a framework to promote regional coordination are necessary.

The current status of inpatient cancer rehabilitation provided by designated cancer hospitals in Japan.

OBJECTIVE: This survey was conducted to clarify the current status of inpatient cancer rehabilitation provided by designated cancer hospitals in Japan. METHODS: A survey questionnaire was sent to 427 designated cancer hospitals in Japan. Information was sought regarding whether inpatient cancer rehabilitation was provided by the center, and if so, whether respondents regarded such provision as satisfactory. RESULTS: Responses were obtained from 235/427 surveyed institutions (55.0%). Cancer rehabilitation was provided in inpatient settings by 97.4%. Two-thirds of respondents (67.7%) regarded inpatient cancer rehabilitation provision as still inadequate. The primary reasons claimed for this inadequacy were a lack of human resources, a lack of rehabilitation professionals with the requisite knowledge/skills and patients who would benefit from cancer rehabilitation present but not prescribed. The total number of rehabilitation staff was identified as associated factor of inadequate inpatient cancer rehabilitation in multivariate analysis (odds ratio = 0.979, 95% confidence interval = 0.96-1.00, P = 0.009). CONCLUSIONS: In order to provide adequate cancer rehabilitation, a sufficient supply of rehabilitation staff, education and recognition of the need for cancer rehabilitation within oncology units are necessary.

Immediate effects of stance and swing phase training on gait in patients with stroke.

To compare the effects of gait trainings targeting the stance (stance training) and the swing phases (swing training) among the subjects with stroke, and quantify the characteristics in the subjects who benefitted from either the stance training or the swing training. Sixteen subjects with stroke performed the stance training, which focused on the center of pressure to move from the heel to the forefoot, and the swing training, which focused on the improvement of hip flexion in the swing phase. To investigate the immediate effects of the stance training and the swing training, the instrumented gait analysis was performed before and after training. To quantify the characteristics, subjects were divided into two groups based on the gait speed change. These two groups were compared using clinical examinations. After the stance training, the center of pressure displacement of the paretic limb was increased compared with the swing training. Subjects who benefitted from the stance training had slower Timed Up and Go and weaker paretic hip muscle strength than those who benefitted from the swing training. Stance training may be more effective in subjects with slower Timed Up and Go outcomes and weaker hip muscles.

A multidisciplinary approach to soft-tissue sarcoma of the extremities.

INTRODUCTION: Soft-tissue sarcoma (STS) denotes a group of rare and highly heterogeneous malignant tumors of mesenchymal origin. Accurate histological diagnosis is critical for selecting appropriate treatment. Complete tumor resection is the primary treatment for STS, and the efficacies of radiotherapy and chemotherapy have been tested in the adjuvant setting to improve oncological outcomes. Because most STS lesions arise in the extremities, preserving limb function and managing limb impairment after radical local treatment represent significant challenges. AREAS COVERED: This article reviews the current front-line treatments for patients with extremity STS and discusses the multidisciplinary team-based efforts needed to improve oncological outcomes and survivorship. EXPERT OPINION: Given the rarity, variety, and complexity of STS, a multidisciplinary approach involving experts in various disciplines is vital for improving outcomes in patients ranging from diagnosis to survivorship. A major challenge is building a sustainable system in each region permitting all patients with extremity STS to be treated at high-volume centers with multidisciplinary teams dedicated to this rare and complex disease.

Gait kinematics and physical function that most affect intralimb coordination in patients with stroke.

BACKGROUND: Disturbed lower limb coordination is thought to limit gait ability in patients with stroke. However, the relationship of lower limb coordination with gait kinematics and physical function has not yet been clarified. OBJECTIVE: The purpose of the study was to clarify the gait kinematic and physical function variables that most affect intralimb coordination by using the continuous relative phase (CRP) between the thigh and shank. METHODS: Fifteen participants with stroke were enrolled in this study. Kinematic and kinetic measurements were recorded during gait at preferred speeds. CRP was defined as the difference between the thigh and shank phase angles. RESULTS: Stepwise analysis revealed that non-paretic CRP during the propulsive phase was a determinant of gait speed. The paretic knee extension and flexion angles were determinants of the CRP during the propulsive phase in the non-paretic limb. Stepwise analysis showed that the paretic knee extension angle was a determinant of the CRP during the propulsive phase in the paretic limb. Stepwise analysis revealed that the paretic knee extensor muscle strength was a determinant of the CRP during the propulsive phase in both limbs. CONCLUSIONS: Our study indicates that improvement in knee movement during the stance phase may improve coordination.

Gait-Synchronized Rhythmic Brain Stimulation Improves Poststroke Gait Disturbance: A Pilot Study.

Background and Purpose- Gait disturbance is one of serious impairments lowering activity of daily life in poststroke patients. The patients often show reduced hip and knee joint flexion and ankle dorsiflexion of the lower limbs during the swing phase of gait, which is partly controlled by the primary motor cortex (M1). In the present study, we investigated whether gait-synchronized rhythmic brain stimulation targeting swing phase-related M1 activity can improve gait function in poststroke patients. Methods- Eleven poststroke patients in the chronic phase participated in this single-blind crossover study. Each patient received oscillatory transcranial direct current stimulation over the affected M1 foot area and sham stimulation during treadmill gait. The brain stimulation was synchronized with individual gait rhythm, and the electrical current peaks reached immediately before initiation of the swing phase of the paretic lower limb. Ankle dorsiflexion was assisted by electrical neuromuscular stimulation in both real and sham conditions. Results- Regarding the effects of a single intervention, the speed of self-paced gait was significantly increased after oscillatory transcranial direct current stimulation, but not after sham stimulation (paired t test, P=0.009). After we administered the intervention repeatedly, self- and maximally paced gait speed and timed up and go test performance were significantly improved (self-paced: F(1,21)=8.91, P=0.007, maximally paced: F(1,21)=7.09, P=0.015 and timed up and go test: F(1,21)=12.27, P=0.002), along with improved balance function and increased joint flexion of the paretic limbs during gait. Conclusions- These findings suggest that rhythmic brain stimulation synchronized with gait rhythm might be a promising approach to induce gait recovery in poststroke patients. Clinical Trial Registration- URL: https://www.umin.ac.jp/ctr/. Unique identifier: UMIN000013676.

Intra-individual biomechanical effects of a non-microprocessor-controlled stance-yielding prosthetic knee during ramp descent in persons with unilateral transfemoral amputation.

BACKGROUND:: A stance-yielding mechanism for prosthetic knees may reduce lower limb loading during specific activities, but quantitative data are insufficient. OBJECTIVES:: To clarify the biomechanical effect of a non-microprocessor-controlled stance-yielding mechanism on ramp descent for individuals with unilateral transfemoral amputation. STUDY DESIGN:: Intra-subject intervention study. METHODS:: Seven individuals with unilateral transfemoral amputation underwent three-dimensional motion analysis of ramp descent with and without activating a stance-yielding mechanism. Regarding early-stance internal joint moment and ground reaction force, whole-group and subgroup analyses stratified by stance prosthetic knee flexion were performed to verify differences in prosthetic side and contralateral limb loading between conditions. RESULTS:: Whole-group analysis revealed significant reduction in early-stance prosthetic knee extension moment with stance-yielding mechanism activation. Changes in prosthetic side hip extension moment and contralateral limb loading were inconsistent between conditions. Subjects with prosthetic stance knee flexion walked slower with a smaller stride and greater increase in aft ground reaction force and ankle dorsiflexion moment when stance-yielding was activated. CONCLUSION:: Stance-yielding mechanism has a biomechanical potential to decrease excessive knee hyperextension. However, prosthetic side stance knee flexion induced by the stance-yielding mechanism might not necessarily reduce the mechanical load on residual hip or contralateral lower limb joints. CLINICAL RELEVANCE: This study showed individual variability in the possibility of reducing the load on the remaining lower limb when using a non-microprocessor-controlled stance-yielding knee. This suggests that individualized prosthetic management and monitoring the activities of individuals wearing a stance-yielding prosthetic knee are crucial to maximize the benefits of stance-yielding prosthetic knees.

Kinetic differences between level walking and ramp descent in individuals with unilateral transfemoral amputation using a prosthetic knee without a stance control mechanism.

BACKGROUND: Individuals with transfemoral amputation (TFA) have difficulty in descending ramps. Although individuals with TFA who descend ramps are speculated to have greater biomechanical demands, this has not been quantified. RESEARCH QUESTION: How do individuals with TFA wearing a prosthetic knee without a stance control mechanism adapt their gait biomechanics to a slightly declined surface? METHODS: We retrospectively analyzed data of level walking and ramp descent (5° decline) from six subjects with TFA who used a prosthesis without a stance control mechanism. Ground reaction force and joint moment, power, and kinematics were derived from three-dimensional motion capture, combined with force measurement. Kinematic and kinetic variables were compared during level walking and ramp descent using the paired tests. RESULTS: Compared with level walking, ramp descent increased the maximum contralateral vertical ground reaction force by 16% of the body weight, on average (standard deviation: 20%). Ramp descent tended to induce smaller concentric hip power during late swing and greater hip eccentric power on the prosthetic-side during late stance. Greater biomechanical demands during ramp descent were indicated by increased maximum medial ground reaction force on both sides, and eccentric joint power of the contralateral ankle during stance. SIGNIFICANCE: For individuals with TFA using a prosthetic knee without a stance control mechanism, descending a ramp can increase loading on the contralateral limb during the loading response; slower walking may alleviate the effect. Ramp descent can change prosthetic-side hip muscles' control of the swinging prosthetic limb, eccentric work on the contralateral ankle plantarflexors during stance, and mediolateral balance. All of these factors should be taken into consideration when individuals with TFA learn to descend a ramp.

Different Conformations of Surface Cellulose Molecules in Native Cellulose Microfibrils Revealed by Layer-by-Layer Peeling.

Layer-by-layer peeling of surface molecules of native cellulose microfibrils was performed using a repeated sequential process of 2,2,6,6-tetramethylpiperidine-1-oxyl radical-mediated oxidation followed by hot alkali extraction. Both highly crystalline algal and tunicate celluloses and low-crystalline cotton and wood celluloses were investigated. Initially, the C6-hydroxy groups of the outermost surface molecules of each algal cellulose microfibril facing the exterior had the gauche-gauche (gg) conformation, whereas those facing the interior had the gauche-trans (gt) conformation. All the other C6-hydroxy groups of the cellulose molecules inside the microfibrils contributing to crystalline cellulose I had the trans-gauche (tg) conformation. After surface peeling, the originally second-layer molecules from the microfibril surface became the outermost surface molecules, and the original tg conformation changed to gg and gt conformations. The plant cellulose microfibrils likely had disordered structures for both the outermost surface and second-layer molecules, as demonstrated using the same layer-by-layer peeling technique.

Effect of higher muscle coactivation on standing postural response to perturbation in older adults.

BACKGROUND: Although several studies have reported that muscle coactivation during postural control increases with age, the effect of higher muscle coactivation on standing postural response to perturbation is unknown. AIMS: To investigate whether higher muscle coactivation affects standing postural response to perturbation in older adults. METHODS: Thirty-four community-dwelling older participants were randomly assigned either to the coactivation group (CG), where muscle coactivation was increased intentionally, or to the non-coactivation group (NCG). The participants were instructed to stand on a force plate that moved forward or backward. Electromyography data were collected from the lower leg muscles. We requested the participants in the CG to increase the activity of their tibialis anterior, and to maintain this posture during the tasks. We moved the force plate with a constant amplitude and velocity, and measured kinematic data with a camera during the tasks. RESULTS: During forward transfer, the knee extension and hip flexion decreased in the CG after perturbation compared to NCG, and the trunk extension angle increased. The center of pressure (COP) displacement decreased around the peak of the movement in the CG compared to NCG. During backward transfer, ankle dorsal and knee flexion changed after perturbation in the CG compared to NCG. DISCUSSION AND CONCLUSION: Our study found that higher muscle coactivation inhibits lower limb and COP movement as well as increases trunk tilt and the risk for falls during forward perturbations. Postural control with higher coactivation appears to be inefficient for maintaining balance during the backward sway of posture.

Effects of High- and Low-Velocity Resistance Training on Gait Kinematics and Kinetics in Individuals with Hip Osteoarthritis: A Randomized Controlled Trial.

OBJECTIVE: The aim of this study was to investigate the effects of high-velocity (HV) and low-velocity (LV) resistance training on gait kinematics and kinetics in patients with hip osteoarthritis. DESIGN: This was a single-blind, randomized controlled trial. Forty-six women with hip osteoarthritis were randomly allocated to the HV (n = 23) or LV (n = 23) training group. The participants underwent an 8-week home-based the HV or LV resistance-training program, involving the hip and knee muscles. Outcome measures included gait kinematics and kinetics using 3-dimensional analyses, muscle strength and power, the Harris Hip Score, and hip pain using the visual analog scale. RESULTS: There was no significant difference in changes for any of the outcome measures between groups. After the training session, muscle power, walking speed, and cadence significantly increased only in the HV group, whereas stride length and the peak hip extension angle during gait significantly increased, and pain on the visual analog scale and the peak ankle dorsiflexion moment during gait significantly decreased only in the LV group. Muscle strength and Harris Hip Score significantly increased in both groups. CONCLUSIONS: The results of this study may indicate that the potential effect of resistance training on abnormal gait pattern depends on movement velocities during training.

Muscle contributions to center of mass excursion in ankle and hip strategies during forward body tilting.

Humans employ two distinct strategies to maintain balance during standing: the ankle and hip strategies. People with a high fall risk tend to alter their motion patterns during forward body tilting from a hip to an ankle strategy. Improved knowledge regarding how muscles control the center of mass (COM) during balancing would facilitate clinical assessment. The present study aimed to investigate individual muscle contributions to COM motion during forward body tilting with both ankle and hip strategies in 16 healthy adults. While standing, participants were instructed to oscillate their bodies and touch anterior and posterior targets at 0.5Hz. The anterior target was positioned at the sternum height level in a HIGH and 5% lower in a LOW condition to induce ankle and hip strategies, respectively. The muscle tension force was calculated from measured angle data using a two-dimensional, muscle-driven forward simulation model. Muscle contributions to COM acceleration during forward body tilting were calculated via induced acceleration analysis. Long hamstrings were found to increase upward-contributing action and forward COM acceleration in the LOW condition during forward tilting. In contrast, the contribution of the soleus to backward COM acceleration was reduced. These results imply that the contribution of hamstrings to forward COM acceleration is disadvantageous to fore-aft COM control and balance recovery during forward body tilting.

Knee rotationplasty: motion of the body centre of mass during walking.

Knee rotationplasty (KRP) is a type of surgery in which the rotated ankle serves as a new knee after being removed for bone tumor. Although this limb salvage surgery is rarely indicated in properly selected patients, it may offer functional advantages over transfemoral amputation, and more durable results compared with a prosthesis. The walking mechanics of adult patients after KRP is believed to be close to that of below-knee amputees. In this study, we evaluated steady-state walking of KRP patients from the viewpoint of the overall muscle power needed to keep the body centre of mass in motion. Three adult patients after KRP, all athletes, were evaluated. Ground reactions during walking were recorded during six subsequent strides on a force treadmill. The positive mechanical work and power sustaining the motion of the centre of mass and the recovery of muscle energy due to the pendulum-like mechanism of walking were computed and compared with those obtained in previous studies from above-knee, below-knee amputees and healthy individuals. In KRP patients, walking was sustained by a muscle power output which was 1.4-3.6 times lower during the step performed on the rotated limb than on the subsequent step. The recovery of muscle energy was slightly lower (0.9) or higher (1.3-1.4 times) on the affected side. In two out of the three KRP patients, our findings were more similar to those from above-knee amputees than to those from below-knee amputees. After KRP, the rotated limb does not necessarily provide the same power provided by below-knee amputation. This may have a relevance for the paralympic classification of KRP athletes.

Association between physical function and the load pattern during stepping-up motion in community-dwelling elderly women.

OBJECTIVE: Stepping-up motion is challenging task for elderly people in daily life. The present study investigated the relationship between the load pattern during stepping-up motion at maximum speed and physical function in elderly women. METHODS: The subjects comprised 109 community-dwelling elderly women (age 72.5±5.3years). The load pattern (maximum load, rate of load production, and stepping-up time) during ascending a 30cm step at maximum speed was measured, using a step up platform that measures the load at the lower and upper level. Physical function, including hip and knee extensor strength and performance on the vertical jump test, one-legged stance test, timed "Up & Go" (TUG) test, and stepping test were measured. RESULTS: Pearson's correlation analysis showed that stepping-up time was correlated with the maximum load at the lower level (r=-0.51), but not with the maximum load at the upper level. A multiple regression analysis showed that hip extensor strength and performance on the vertical jump, TUG, and stepping tests were significant determinants of the load pattern during stepping-up motion in the elderly women. CONCLUSIONS: Our study revealed that rapid stepping-up ability was more closely related to the maximum load during push-off at the lower level rather than that during weight loading on the upper level, and that the load pattern during stepping-up motion in elderly women was associated with various physical functions such as the hip extensor strength, leg muscle power, dynamic balance function, and agility.