Simon Fuk-Tan Tang

Ultrasound guidance in caudal epidural needle placement.

Background:This study was conducted to investigate the feasibility of using ultrasound as an image tool to locate the sacral hiatus accurately for caudal epidural injections. Methods:Between August 2002 and July 2003, 70 patients (39 male and 31 female patients) with low back pain and sciatica were studied. Soft tissue ultrasonography was performed to locate the sacral hiatus. A 21-gauge caudal epidural needle was inserted and guided by ultrasound to the sacral hiatus and into the caudal epidural space. Proper needle placement was confirmed by fluoroscopy. Results:In all the recruited patients, the sacral hiatus was located accurately by ultrasound, and the caudal epidural needle was guided successfully to the sacral hiatus and into the caudal epidural space. There was 100% accuracy in caudal epidural needle placement into the caudal epidural space under ultrasound guidance as confirmed by contrast dye fluoroscopy. Conclusions:Ultrasound is radiation free, is easy to use, and can provide real-time images in guiding the caudal epidural needle into the caudal epidural space. Ultrasound may therefore be used as an adjuvant tool in caudal needle placement.

Ultrasound-guided shoulder injections in the treatment of subacromial bursitis.

Chen MJL, Lew HL, Hsu TC, Tsai WC, Lin WC, Tang SFT, Lee YC, Hsu RCH, Chen CPC: Ultrasound-guided shoulder injections in the treatment of subacromial bursitis. Am J Phys Med Rehabil 2006;85:31–35. Objective:To investigate the treatment effectiveness between ultrasound-guided and blind injection techniques in the treatment of subacromial bursitis. Design:A total of 40 patients with sonographic confirmation of subacromial bursitis were recruited into this study. These patients were divided into blind and ultrasound-guided injection groups. The shoulder abduction range of motion was compared before injections and 1 wk after the completion of injections in both groups. Results:The shoulder abduction range of motion before injection in the blind injection group was 71.03 ± 12.38 degrees and improved to 100 ± 18.18 degrees 1 wk after the injection treatments. However, the improvement did not reveal significant statistical differences (P > 0.05). The shoulder abduction range of motion before injection in the ultrasound-guided injection group was 69.05 ± 14.72 degrees and improved to 139.29 ± 20.14 degrees 1 wk after the injection treatments (P < 0.05). Conclusions:Ultrasound may be used as an adjuvant tool in guiding the needle accurately into the inflamed subacromial bursa. The ultrasound-guided injection technique can result in significant improvement in shoulder abduction range of motion as compared with the blind injection technique in treating patients with subacromial bursitis.

Sagittal plane loading response during gait in different age groups and in people with knee osteoarthritis.

Chen CPC, Chen MJL, Pei YC, Lew HL, Wong PY, Tang SFT: Sagittal plane loading response during gait in different age groups and in people with knee osteoarthritis. Am J Phys Med Rehabil 2003;82:307–312. Objective To investigate the gait patterns and the sagittal ground reaction forces in different age groups and in people with knee osteoarthritis. Design Motion analysis and force platform data were collected for a total of 55 female subjects capable of independent ambulation. Subjects were divided into three groups consisting of the control group, the elderly group, and the osteoarthritis knee group. Gait parameters of walking velocity, cadence, step length, stride time, single- and double-support time, and sagittal ground reaction forces were obtained during comfortable walking speed. Gait analysis was performed in a tertiary hospital’s gait laboratory. Variables were analyzed using a univariate repeated-measures analysis of variance. Statistical significance was set at a value of P < 0.05. Results The osteoarthritis knee group had slower walking velocity, lower cadence, and longer stride time as compared with the elderly and young control groups (P < 0.05). In ground reaction force studies, the first peak time, expressed in percentage of gait cycle, was significantly longer in the osteoarthritis knee group (20.8 ± 3.2) as compared with the elderly (17.8 ± 2.0) and young control groups (17.1 ± 1.8, P < 0.01). The force during time of minimal midstance was larger in the osteoarthritis knee group (90.9 ± 5.3) as compared with the elderly and young control groups (P < 0.05). The second peak force was significantly smaller in the osteoarthritis knee group as compared with the young control group (P < 0.01). The force change in the midfoot region in the osteoarthritis knee and elderly groups revealed more loading force onto the midfoot region during midstance as compared with the young control group (P < 0.01). Conclusion Gait parameters in the elderly and osteoarthritis knee patients were characterized by slower walking velocity, lower cadence, shorter step length, longer stride time, and longer double-support time. Less heel contact and push-off forces were noticed in these two groups, with more loading force onto the midfoot during midstance.

Longitudinal followup study of ultrasonography in congenital muscular torticollis.

High-resolution ultrasonography was used to examine affected sternocleidomastoid muscles in patients with congenital muscular torticollis at different times. Thirty-one female and 42 male patients were recruited and classified as having one of four types of fibrosis based on the sonograms. Compared with initial assessment, 22 (95.6%) patients with Type I fibrosis and 22 (57.9%) patients with Type II fibrosis had a change in classification at the end of the study. Among the patients with Type I fibrosis, the classification of one patient was changed to Type III fibrosis, the classifications of two patients were changed to normal muscle, and the classifications of the other patients were changed to Type II fibrosis. For patients with Type II fibrosis, the classifications of two patients were changed to Type III fibrosis, the classifications of three patients were changed to Type IV fibrosis, and the classifications of the other patients were changed to normal muscle. No changes in classification of patients with Types III and IV fibrosis occurred during followup. Patients with Type IV fibrosis had a significantly high incidence of surgical intervention. Congenital muscular torticollis is a dynamic disease. Ultrasonography can be valuable in observing the alteration. Aggressive management may be necessary for patients with Type IV fibrosis.

Measurement of forefoot varus angle by laser technology in people with flexible flatfoot.

Chen MJL, Chen CPC, Lew HL, Hsieh WC, Yang WP, Tang SFT: Measurement of forefoot varus angle by laser technology in people with flexible flatfoot. Am J Phys Med Rehabil 2003;82:842–846. Objective The purpose of this study was to measure the forefoot varus angles in subjects with and without flexible flatfoot (FF) by using laser foot-scanning technology. Design In the rehabilitation laboratory of a tertiary medical center, 70 subjects with FF, ranging in age from 10 to 50 yr, were recruited. The control group consisted of 30 volunteers without clinical evidence of FF. A total of 100 positive casts were obtained by having their subtalar joints kept in a neutral position. The plantar surface of the positive cast was scanned by a Yeti 3D Foot Scanner. A straight line was drawn between the first and fifth metatarsophalangeal joints. The forefoot varus angle was measured from this line in relation to the line parallel to the ground. Results The mean forefoot varus angle was calculated to be 5.01 ± 4.51 degrees in our FF subjects, and 1.23 ± 1.96 degrees in the control group. Significant statistical difference in forefoot varus angle was noted between these two groups. Conclusions The laser foot-scanning technique offers fast and accurate measurement of the forefoot varus angles. An average forefoot varus angle of approximately 5 degrees was observed in subjects with FF, which was significantly greater than the subjects without FF. Therefore, we recommend the concept of incorporating adequate forefoot posting at the medial forefoot area of an insole in treating people with FF.

The Relationship Between Parental Concerns and Final Diagnosis in Children With Developmental Delay

Parental concern is a useful screening approach for early detection of children with developmental delay. We investigated the relationships among parental concerns, functional impairment, and final diagnosis of children (n = 273) with developmental delays. Of these, motor, language, and global delay were most common. Parental concerns, especially in language and motor development, were good predictors of children with language or motor delay, and provided reliable information for detection of children with delays in these domains. Parents were less likely to identify children with cognitive problems, global delay, or associated behavioral problems. Co-occurrence of developmental disorders was also recognized, especially in children with global delay. We conclude that parental concerns are useful information for detection of specific developmental problems in children. Because co-occurrence of developmental disorders is common, their early recognition would be helpful for better care of these children.

Changes in windlass effect in response to different shoe and insole designs during walking

Windlass effect occurs during the pre-swing phase of gait cycle in which the peak tensile strain and force of the plantar aponeurosis (PA) is reached. The increased dorsiflexion angle of the 1st metatarsophalangeal (MTP) joint is the main causing factor. The aim of this study was to investigate thoroughly in finding the appropriate shoe and insole combination that can effectively decrease the windlass effect. Foot kinematic analyses of 10 normal volunteers (aged 25.2±2.1 years, height of 167.4±9.1 cm, and weight of 66.2±18.1 kg) were performed during gait under the conditions of barefoot, standard shoe (SS) with flat insole (FI) or carbon fiber insole (CFI), and rocker sole shoe (RSS) with FI or CFI. The shoe cover consisting of transparent polymer was used for accurate measurement of kinematic data as specific areas on the cover can be cut away for direct placement of reflective markers onto the skin. Under barefoot condition, the mean of maximum dorsiflexion angle of the 1st MTP joint was measured to be 48.0±7.3°, and decreased significantly to 28.2±5.7° when wearing SS with FI, and 24.1±5.7° when wearing SS with CFI. This angle was further decreased to around 13° when wearing RSS with FI or CFI. Subjects wearing footwear alone can increase the minimum medial longitudinal angle and decrease the maximum plantarflexion angle of metatarsus related to the calcaneus as compared with barefoot condition, resulting in flatter medial foot arch. Results suggested that RSS is the effective footwear in reducing the windlass effect regardless the type of insole inserted. The findings in this study provided us with the evidences in finding the appropriate footwear for treating foot disorders such as plantar fasciitis by effectively reducing the windlass effect.

Ultrasound as a Screening Tool for Proceeding With Caudal Epidural Injections

OBJECTIVE To study the anatomical structure of the sacral hiatus using ultrasound. Based on the sonographic images of the sacral hiatus, the feasibility of caudal epidural injection can then be assessed. DESIGN Case-controlled study. SETTING Rehabilitation outpatient clinic in a tertiary medical center. PARTICIPANTS Patients (N=47; 20 women, 27 men) with low back pain and sciatica who were to receive caudal epidural injection treatments were recruited into this study. INTERVENTIONS Sonographic images of the sacral hiatus were obtained from all the patients. An ultrasound machine capable of examining musculoskeletal tissues with real-time linear-array ultrasound transducer was used to measure the distance between the anterior wall and posterior wall of the sacral hiatus (diameter of the sacral hiatus) and the distance between bilateral cornua. MAIN OUTCOME MEASURES Diameter of the sacral canal and distance between bilateral cornua measured in millimeters. RESULTS The mean diameter of the sacral canal was measured to be 5.3+/-2.0 mm in our recruited patients. The mean distance between bilateral cornua was measured to be 9.7+/-1.9 mm. Caudal epidural injections failed in 7 patients. In these 7 patients, 4 had very small diameter of the sacral canal (1.6, 1.2, 1.4, and 1.5 mm). In 1 man, sonographic images revealed a closed sacral hiatus (no sacral canal diameter can be measured). Two patients revealed flow of fresh blood into the syringe while checking for the escape of cerebrospinal fluid after the needles were inserted into the sacral canal. For safety reasons, steroid injections were not performed in these 2 patients. CONCLUSIONS Ultrasound may be used as an effective screening tool for caudal epidural injections. Anatomic variations of the sacral hiatus can be clearly observed using ultrasound. Sonographic images indicating a closed sacral canal and sacral diameters ranging from 1.2 to 1.6mm may suggest a higher failure rate in caudal epidural injection.

Kinematic Features of Rear-Foot Motion Using Anterior and Posterior Ankle-Foot Orthoses in Stroke Patients With Hemiplegic Gait

OBJECTIVE To evaluate the kinematic features of rear-foot motion during gait in hemiplegic stroke patients, using anterior ankle-foot orthoses (AFOs), posterior AFOs, and no orthotic assistance. DESIGN Crossover design with randomization for the interventions. SETTING A rehabilitation center for adults with neurologic disorders. PARTICIPANTS Patients with hemiplegia due to stroke (n=14) and able-bodied subjects (n=11). INTERVENTIONS Subjects with hemiplegia were measured walking under 3 conditions with randomized sequences: (1) with an anterior AFO, (2) with a posterior AFO, and (3) without an AFO. Control subjects were measured walking without an AFO to provide a normative reference. MAIN OUTCOME MEASURES Rear-foot kinematic change in the sagittal, coronal, and transverse planes. RESULTS In the sagittal plane, compared with walking with an anterior AFO or without an AFO, the posterior AFO significantly decreased plantar flexion to neutral at initial heel contact (P=.001) and the swing phase (P<.001), and increased dorsiflexion at the stance phase (P=.002). In the coronal plane, the anterior AFO significantly increased maximal eversion to neutral (less inversion) at the stance phase (P=.025), and decreased the maximal inversion angle at the swing phase when compared with using no AFO (P=.005). The posterior AFO also decreased the maximal inversion angle at the swing phase as compared with no AFO (P=.005). In the transverse plane, when compared with walking without an AFO, the anterior AFO and posterior AFO decreased the adduction angle significantly at initial heel contact (P=.004). CONCLUSIONS For poststroke hemiplegic gait, the posterior AFO is better than the anterior AFO in enhancing rear-foot dorsiflexion during a whole gait cycle. The anterior AFO decreases rear-foot inversion in both the stance and swing phases, and the posterior AFO decreases the rear-foot inversion in the swing phase when compared with using no AFO.

Effects of an Anterior Ankle-Foot Orthosis on Postural Stability in Stroke Patients with Hemiplegia

Chen C-K, Hong W-H, Chu N-K, Lau Y-C, Lew HL, Tang SFT: Effects of an anterior ankle–foot orthosis on postural stability in stroke patients with hemiplegia. Am J Phys Med Rehabil 2008;87:815–820. Objective:To evaluate the effects of an anterior leaflet ankle–foot orthosis (AFO) on postural stability in stroke patients with hemiplegia. Design:Twenty-one stroke patients with hemiplegia resulting from new-onset stroke and ten normal subjects were included in this study. The SMART balance master system was used to assess the postural stability by measuring the ankle strategy, maximal stability, and velocity of center-of-gravity (COG) movement under the following six conditions: (1) eyes open and fixed support (EOFS), (2) eyes closed and fixed support (ECFS), (3) sway-referenced vision and fixed support (SVFS), (4) eyes open and sway-referenced support (EOSS), (5) eyes closed and sway-referenced support (ECSS), and (6) sway-referenced vision and support (SVSS). Each patient was tested with and without an anterior AFO as compared with normal subjects. Results:When wearing an anterior AFO, patients used ankle strategy more than hip strategy to maintain postural stability in all the six sensory conditions (P < 0.05). An anterior AFO also provided stroke patients with better maximal stability under relatively challenging conditions such as SVFS, EOSS, and ECSS (P < 0.05), but the effect was not apparent in the conditions without external perturbation (EOFS and ECFS) and the most difficult condition (SVSS). The velocity of COG movement was lowered when wearing an anterior AFO in stroke patients, and significant differences existed in the EOFS, ECFS, ECSS, and SVSS conditions (P < 0.05). Conclusions:In the early stage of recovery, the use of an anterior AFO may assist stroke patients with hemiplegia to improve their postural stability.