Objective To evaluate the effects of in situ subtalar arthrodesis with bone graft for subtalar traumatic arthritis, and to analyse the plantar pressure distribution so as to provide the evidence for effectiveness evaluation. Methods Between March 2004 and December 2008, 26 patients with unilateral subtalar arthrodesis undergoing bone graft fusion wereenrolled (test group). After operation, the imageology diversity and the effect of subtalar arthrodesis on adjacent joint wereobserved. American Orthopaedic Foot and Ankel Society (AOFAS) ankle and hindfoot score and radiographs were used to assess the foot function before and after operation. Twenty-six normal subjects served as controls. Footscan system was used to test the distribution of maximum plantar pressure and the change of gravity center curve. No significant difference was found in gender, age, height, and weight between 2 groups (P gt; 0.05). Results All patients were followed up 18.2 months on average (range, 14-71 months). The mean subtalar arthrodesis time was 5.6 months (range, 4 months and 15 days to 11 months). The mean AOFAS ankle and hindfoot score improved from 35.18 ± 8.16 preoperatively to 76.36 ± 6.90 postoperatively (t=13.910, P=0.000). Nine (34.6%) patients had satisfactory functional effects, and 13 (50.0%) patients basically satisfactory. The talocalcaneal height, talocalcaneal angle, talar decl ination angle, and calcaneus patch angle were 87.04% ± 6.17%, 76.73% ± 5.13%, 65.86% ± 7.01%, and 70.19% ± 8.33% of the contralateral side, respectively. Osteoarthritis of the adjacent joints occurred in 7 cases. The maximum plantar pressure increased in the third to fifth metatarsal bones and decreased in the first to second metatarsal bones, showing significant differences when compared with normal controls (P lt; 0.05). No significant difference was found in the plantar pressure between arthrodesis foot and contralateral foot of the test group (P gt; 0.05). The plantar pressure was well distributed in patient who was satisfied with the effect, but it was still different from normal controls. In patients who had high plantar pressure n middle foot, mild heel inversion occurred. The gravity center curve of the contralateral foot in the test group was almost the same as that of normal controls; curve medially shifted when forefoot touched down. The curve irregularly and laterally shifted in the subtalar arthrodesis foot; the curve did not medially shift when forefoot touched down. Conclusion In situ subtalar arthrodesis with bone graft has good cl inical results for subtalar traumatic arthritis. Gait analysis can be appl ied to assess the therapeutic effectiveness, and contribute to make a surgical plan. For the adaptive alteration of contralateral side after subtalar arthrodesis, a cohort of normal subjects should be used for comparison in gait analysis.
Objective To provide the objective basis for the evaluation of the operative results of vascularized greater trochanter bone flap in treating osteonecrosis of the femoral head (ONFH) by three-dimensional gait analysis. Methods Between March 2006 and March 2007, 35 patients with ONFH were treated with vascularized greater trochanter bone flap, and gait analysis was made by using three-dimensional gait analysis system before operation and at 1, 2 years afteroperation. There were 23 males and 12 females, aged 21-52 years (mean, 35.2 years), including 8 cases of steroid-induced, 7 cases of traumatic, 6 cases of alcohol ic, and 14 cases of idiopathic ONFH. The left side was involved in 15 cases, and right side in 20 cases. According to Association Research Circulation Osseous (ARCO) classification, all patients were diagnosed as having femoral-head necrosis at stage III. Preoperative Harris hip functional score (HHS) was 56.2 ± 5.6. The disease duration was 1.5-18.6 years (mean, 5.2 years). Results All incisions healed at stage I without early postoperative compl ications of deep vein thrombosis and infections of incision. Thirty-five patients were followed up 2-3 years with an average of 2.5 years. At 2 years after operation, the HHS score was 85.8 ± 4.1, showing significant difference when compared with the preoperative score (t=23.200, P=0.000). Before operation, patients showed a hip muscles gait, short gait, reduce pain gait, and the pathological gaits significantly improved at 1 year after operation. At 1 year and 2 years after operation, step frequency, pace, step length and hip flexion, hip extension, knee flexion, ankle flexion were significantly improved (P lt; 0.01). Acceleration-time curves showed that negative wave and spinous wave at acceleration-stance phase of front feet and hind feet in affected l imb were obviously reduced at 1 year and 2 years after operation. Postoperative petronas wave appeared at swing phase; the preoperative situation was three normal phase waves. Conclusion These results suggest that three-dimensional gait analysis before and after vascularized greater trochanter for ONFH can evaluate precisely hip vitodynamics variation.
Objective To investigate the effect of femoral offset reconstruction on pelvic stabil ity during gait after total hip arthroplasty. Methods According to the inclusion criteria, 29 patients undergoing unilateral total hip arthroplasty between January 2000 and December 2005 were selected. There were 10 males and 19 females with an average age of 64.3 years (range, 33-75 years). The affected hips included 15 left hips and 14 right hips. The follow-up time was from 5 to 10 years (mean, 7.7 years). The Harris score was 90 to 100 (mean, 97) at last follow-up. The femoral offset ratio (FOR) was calculated by measuring the femoral offset of the bilateral hips on radiograph, and then the patients were divided into 2 groups: group A (the femoral offset of diseased hip was less than that of normal hip, n=10) and group B (the femoral offset of diseased hip was greater than that of normal hip, n=19). The pelvis kinematic variables were measured by three-dimensional gait analysis to collect the magnitude of pelvic obl ique angle (POA). Results In group A, the FOR was 0.81 ± 0.08 and the POA was (—0.42 ± 0.91)°. In group B, the FOR was 1.27 ± 0.15 and the POA was (1.02 ± 0.94)°. For the normal hip, the POA was (1.15 ± 0.85)°. The POA was significantly less in group A than in group B and the normal l imb (P lt; 0.05). The difference in POA had no significance between group B and the normal hip (P gt; 0.05). The POA was positive relative with FOR (r=0.534, P=0.003), and the regression equation was y= — 2.551+ 2.781x. Conclusion The femoral offset reconstruction is crucial to improve hip abductor function and gait.
Objective To investigate the value of using Footscan system to evaluate the therapeutic effect of two internal fixation methods on calcaneus fractures. Methods From February 2006 to September 2006, 64 patients with fresh unilateral closed calcaneus fractures were randomly divided into two groups. The experimental group: 32 patients underwentminimally invasive open reduction and internal fixation with improved compressing plate and screw, including 28 males and 4 females aged 20-53 years old (average 36.7 years old); the course of disease was 3-14 days; there were 19 cases of type II, 11 of type III, and 2 of type IV according to Sanders fracture classification system. The control group: 32 patients underwent internal fixation of standard AO plate via L-shaped incision, including 29 males and 3 females aged 18-56 years old (average 37.1 years old); the course of disease was 4-15 days; there were 18 cases of type II, 11 of type III and 23 of type IV according to Sanders fracture classification system. No significant difference was noted between two groups in the general information (P gt; 0.05). At 1 and 2 years after operation, dynamic plantar pressure was measured using Footscan system, Maryland foot scores of two groups was compared, and statistical analysis was performed. Results All patients were followed up for 2 years. No infection, cuticular border necrosis, and sural nerve distal end injury occurred in the experimental group, whereas in the control group, 3 patients suffered from cuticular border necrosis and recovered after dressing, and 1 patient had sural nerve distal end injury with decreased sensation in local skin. At 1 and 2 years after operation, in the control group, there were significant differences between the injured foot and the normal foot in terms of impulse, instep index, motion range of subtalar joint, lateral displacement of footplate pressure center, and calcaneal width when patients stood on both feet (P lt; 0.05), whereas in the experimental group, no significant differences were noted between the injured foot and the normal foot in terms of the above parameters (P gt; 0.05). Significant differences were noted between two groups in terms of the above parameters (P lt; 0.05). The Maryland score 1 yearafter operation was (86.74 ± 8.56) points for the experimental group and (71.24 ± 10.06) points for the control group; at 2 years after operation, it was increased to (87.35 ± 8.49) points and (72.41 ± 9.69) points, respectively, indicating there was a significant difference between two groups (P lt; 0.05). Conclusion Operative outcomes of internal fixation with improved compressing plate are superior to those of standard AO plate. Footscan system can provide a quantitative assessment on the operative effect of calcaneus fractures.
【Abstract】 Objective To establ ish a three-foot weight-bearing canine model to imitate the biomechanical loading environment of the human’s hip joint. To observe and compare the kinetic changes of hind l imbs between normal and three-foot weight bearing canines. Methods Using 10 beagles, three-foot weight-bearing canine models were made by fixing unilateral wrist joints at 90º flexionally. The changes of ground reaction forces and the time of standing phases (Ts) of the hind l imbs were compared by 3-D gait analysis pre- and postoperatively. Results Canines could walk well with three l imbs after the fixation of one fore l imb. However, the gait pattern changed tremendously. The canine walked jumpily by raising its head and neck, and the bilateral hind l imbs kept contacting ground alternately. Ts of ipsilateral hind l imb was (0.48±0.04)s, and Ts of contralateral hind l imb was (0.46±0.06)s. Although, the time durations were increased a l ittle, but there were no significant differences when compared with that of normal canines (0.43±0.05)s (P gt; 0.05). The vertical ground reaction force (Fz) of ipsilateral hind l imbwas (4.63±0.85) body weight, and the Fz of contralateral hind l imb was (4.78±0.49) body weight. There were significant increases when compared with the Fz of normal canines (3.26±0.48) body weight (P lt; 0.05). The peak acceleration force of the ipsilateral hind l imb was (0.80±0.30) body weight. There was significant increase compared with that of normal canines (0.72±0.13) body weight (P lt; 0.05). The peak acceleration force of the contralateral hind l imbs was (0.68±0.22) body weight, there was no difference compared with that of normal canines (P gt; 0.05). The peak deceleration forces of the ipsilateral and contralateral hind l imbs were —(0.26±0.14) body weight and —(0.13±0.05) body weight separately. They decreased significantly when compared with that of normal canines —(0.43±0.13) body weight (P lt; 0.05). In normal canines, the upper l imbs were main load bearingl imbs, they could bear 62.8%±2.4% of body weight. However, the hind l imbs could bear only 37.2%±1.8% of body weight. On the contrary, in three-foot weight-bearing canines, the hind l imbs became the main load bearing l imbs, they could bear 59.1%±6.7% of body weight. Conclusion Three-foot weight-bearing canine model can be used as a candidate animal model to research the effects of biomechanical loading on the progression of hip joint diseases.
Nowadays, for gait instability phenomenon, many researches have been carried out at home and abroad. However, the relationship between plantar pressure and gait parameters in the process of balance adjustment is still unclear. This study describes the human body adaptive balance reaction during slip events on slippery level walk by plantar pressure and gait analysis. Ten healthy male subjects walked on a level path wearing shoes with two contrastive contaminants (dry, oil). The study collected and analyzed the change rule of spatiotemporal parameters, plantar pressure parameters, vertical ground reaction force (VGRF), etc. The results showed that the human body adaptive balance reaction during slip events on slippery level walk mainly included lighter touch at the heel strikes, tighter grip at the toe offs, a lower velocity, a shorter stride length and longer support time. These changes are used to maintain or recover body balance. These results would be able to explore new ideas and provide reference value for slip injury prevention, walking rehabilitation training design, research and development of walking assistive equipments, etc.
Turning gait is very common in daily lives. However, study of turning is still limited. For researching the differences of the walking characteristics between straight gait and turning gait and between different turning strategies, and for analyzing the endopathic factor, this study selected 10 healthy young men to perform straight walking and 90° turning using two turning strategies (outside leg turning and inside leg turning). The Vicon capture system and plantar pressure capture system were used to measure gait parameters and plantar pressure parameters at the same time. The study showed that stride velocity reduced while stride time and proportion of stance time increased when turning was compared to straight walking. Inside leg turning strategy needed stronger muscle controlling and could promote turning, while outside leg turning strategy was more stable. This results will offer data for projecting gait of biped robot and provide reference value for walking rehabilitation training design and development of walking assistive equipments, etc.
ObjectiveTo provides an objective tool to evaluate rotator cuff function in rats. MethodsSixty adult male Sprague Dawley rats, weighing (281.21± 20.12) g, were involved in this experiment. Botulinum toxin A (6 U/kg) was injected into the infraspinatus of 12 rats in Botox group. Infraspinatus tendons of 12 rats in tear group were cut by microinvasive method. Infraspinatus tendons of 12 rats in sham-operation group were exposed but not cut. No any treatment was performed on the 12 rats in normal control group. One shoulder joint of each rat was selected randomly as treatment side. After 7 days, cadence, rate of stand phase, support pressure, swing speed, stand speed, and stride length of rats in those 4 groups were measured. Treatment side and contralateral side ratio of each gait parameter was caculated. If parameters of Botox group and tear group both showed significant differences compared with those of normal control group and sham-operation group, the gait parameter was brought into rating scale as an item. Each item was assigned from 1 point to 5 points according to gait parameter. The chronic rotator cuff injury model was established in 12 rats of verification group and rating scale was used to evaluate rotator cuff function each week for 8 weeks after surgery. ResultsAll gait parameters of tear group were significantly less than those of Botox group (P＜0.05), and Botox group was significantly less than sham-operation group and normal control group (P＜0.05), but no significant difference was found between sham-operation group and normal control group (P>0.05). All gait parameters were brought into rating scale as items. All items were rated from 1 point to 5 points, so the total score was 30 points and the lowest score was 6 points. Thirty points meant normal function of infraspinatus (rotator cuff function was normal), and 6 points meant complete loss of infraspinatus function (rotator cuff function was severely damaged). Rotator cuff functional scores of rats in verification group were 27.00±1.86, 23.75±2.83, 21.33±1.92, 18.17±2.37, 13.17±1.64, 11.67±2.50, 8.17±1.27, 6.50±0.67 from the 1st week to the 8th week respectively. ConclusionThe rating scale of rat rotator cuff function may reflect the severity of rotator cuff injury and the functional status of rotator cuff to some extent in rats.
The purpose of this study is to determine how restricting inversion-eversion and pronation-supination motions of the ankle joint complex influences the stability of human gait. The experiment was carried out on a slippery level ground walkway. Spatiotemporal gait parameter, kinematics and kinetics data as well as utilized coefficient of friction (UCOF) were compared between two conditions, i.e. with restriction of the ankle joint complex inversion-eversion and pronation-supination motions (FIXED) and without restriction (FREE). The results showed that FIXED could lead to a significant increase in velocity and stride length and an obvious decrease in double support time. Furthermore, FIXED might affect the motion angle range of knee joint and ankle joint in the sagittal plane. In FIXED condition, UCOF was significantly increased, which could lead to an increase of slip probability and a decrease of gait stability. Hence, in the design of a walker, bipedal robot or prosthetic, the structure design which is used to achieve the ankle joint complex inversion-eversion and pronation-supination motions should be implemented.
This paper presents a wearable exoskeleton robot system to realize walking assist function, which oriented toward the patients or the elderly with the mild impairment of leg movement function, due to illness or natural aging. It reduces the loads of hip, knee, ankle and leg muscles during walking by way of weight support. In consideration of the characteristics of the psychological demands and the disease, unlike the weight loss system in the fixed or followed rehabilitation robot, the structure of the proposed exoskeleton robot is artistic, lightweight and portable. The exoskeleton system analyzes the user's gait real-timely by the plantar pressure sensors to divide gait phases, and present different control strategies for each gait phase. The pressure sensors in the seat of the exoskeleton system provide real-time monitoring of the support efforts. And the drive control uses proportion-integral-derivative (PID) control technology for torque control. The total weight of the robot system is about 12.5 kg. The average of the auxiliary support is about 10 kg during standing, and it is about 3 kg during walking. The system showed, in the experiments, a certain effect of weight support, and reduction of the pressure on the lower limbs to walk and stand.