Ngok-Kiu Chu

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.

Improvement of gait by using orthotic insoles in patients with heel injury who received reconstructive flap operations

Tang SFT, Chen CPC, Hong WH, Chen HT, Chu NK, Leong CP: Improvement of gait by using orthotic insoles in patients with heel injury who received reconstructive flap operations. Am J Phys Med Rehabil 2003;82:350-356. Objective To investigate the effect of orthotic insoles in heel injury patients who received reconstructive flap operations. Design Motion analysis and force platform data were collected in able-bodied subjects and patients with heel injuries during walking without and with the use of the total contact insole. Gait kinetics were collected for the hip, knee, and ankle joints and then compared with Student’s t tests. Results Walking velocity and step length were decreased (P < 0.014 and P < 0.005) for patients not wearing the total contact insole. The affected limbs had longer double-support duration (14.8% of gait cycle, P < 0.037) and shorter single-support duration (34.5% of gait cycle, P < 0.045). Less hip power generation was noted for the affected limbs during both initial contact and preswing phases, 0.17 ± 0.10 N-m/kg-m and 0.45 ± 0.20 N-m/kg-m, as compared with that of the able-bodied subjects, 0.36 ± 0.08 N-m/kg-m and 0.89 ± 0.22 N-m/kg-m, respectively. Decreased ankle power generation was noted for the affected limbs (1.08 ± 0.38 N-m/kg-m) during preswing phase as compared with the able-bodied subjects (2.24 ± 0.33 N-m/kg-m). After fitting of the total contact insole, the affected limbs recovered to a gait pattern similar to that of the able-bodied subjects (P < 0.05). Conclusion Asymmetry of gait pattern after heel injury resulted in altered gait kinetics. Gait symmetry could be recovered in these patients as the total contact insole provides weight acceptance, shock absorption, and cushioning effect for the reconstructed heels.

Relationship between the EMG ratio of muscle activation and bony structure in osteoarthritic knee patients with and without patellar malalignment.

OBJECTIVE The aim of this study was to compare muscle activation patterns and patellofemoral joint morphologies between patients with knee osteoarthritis with and without patellar malalignment. SUBJECTS The subjects were divided into 3 groups. Group A comprised 11 patients with symptomatic knee osteoarthritis without patellar malalignment. Group B comprised 14 patients with symptomatic knee osteoarthritis with patellar malalignment. Group C comprised 10 age-matched subjects with non-knee osteoarthritis as controls. METHODS Isokinetic dynamometry with surface electromyography was used to measure maximal muscle activity in terms of vastus medialis oblique/vastus lateralis ratios. Merchants view was taken to analyse the bony anatomy of the patellofemoral joint. Recordings were made at angular velocities of 80, 120 and 240 masculine/sec. RESULTS The electromyographic ratios of group B were lower than groups A and C for all testing velocities (p<0.05). Group B also had larger sulcus angles, lateral patellar tilt and displacement. The electromyographic ratios correlated negatively with sulcus angles. CONCLUSION Subjects with knee osteoarthritis with patellar malalignment exhibited an imbalance in quadriceps contraction, as confirmed by altered vastus medialis oblique/vastus lateralis ratios associated with larger sulcus angles of the patellofemoral joints. The sulcus angle may be an important contributing factor in causing abnormal patellar tracking in knee osteoarthritis.

Transmetatarsal amputation prosthesis with carbon-fiber plate: Enhanced gait function

Tang SFT, Chen CPC, Chen MJL, Chen WP, Leong CP, Chu NK: Transmetatarsal amputation prosthesis with carbon-fiber plate: Enhanced gait function. Am J Phys Med Rehabil 2004;83:124–130. ObjectiveTo determine whether the design of a transmetatarsal amputation prosthesis with a carbon-fiber plate would improve gait pattern in patients with transmetatarsal amputations. DesignIn the gait laboratory in a tertiary medical center, eight male patients with transmetatarsal amputations were recruited. Nine able-bodied male volunteers were recruited as the control group. A full-length standard shoe and a transmetatarsal amputation prosthesis with a carbon-fiber plate were the footwear used. Our transmetatarsal amputation prosthesis included a custom-molded insole, a mounted toe filler, and a thin, lightweight, carbon-fiber plate incorporated directly beneath the insole. ResultsAfter wearing the transmetatarsal amputation prosthesis with a carbon-fiber plate, the results of the kinetic and kinematic studies were summarized. ConclusionThe transmetatarsal amputation prosthesis with a carbon-fiber plate improved gait pattern significantly in patients with transmetatarsal amputations. Drastic shoe modifications are not necessary to have the prosthesis inserted. The carbon-fiber plate functions like the spring-steel shank within the sole of the shoe. The carbon-fiber plate, the toe filler, and the total-contact insole are all mounted as a whole to ensure better foot contact. Therefore, our transmetatarsal amputation prosthesis with a carbon-fiber plate can be a good alternative choice of footwear in patients with transmetatarsal amputations.

Ultrasound-guided injection treatment of retrocalcaneal bursitis.

From the Department of Physical Medicine & Rehabilitation, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Gueishan, Taoyuan County, Taiwan (N-KC, CPCC); Defense and Veterans Brain Injury Center, Richmond, VA, Department of Physical Medicine and Rehabilitation, Virginia Commonwealth University, Richmond, VA, and University of Hawaii, John A Burns School of Medicine, Honolulu, HI (HLL).

Attack of Gouty Arthritis after Intraarticular Injection of Naturally Derived Hyaluronic Acid

Viscosupplementation by intraarticular administration of exogenous hyaluronic acid has been a favorable treatment option to alleviate the symptoms of knee osteoarthritis. The potential but uncommon adverse reactions associated with intraarticular hyaluronic acid injection are local pain, swelling, and allergic response. These reactions are typically mild, transient, and self-limiting. The focus of this report is an 80-year-old man who presented with acute painful swelling of his knee joint after an injection of naturally derived hyaluronic acid. Aspiration of knee joint effusion yielded 40 mL of turbid straw-colored fluid. Synovial fluid cell counts revealed numerous leukocytes with a marked predominance of neutrophils. Intraleukocytic needle-shaped crystals with intensely negative birefringence were identified with polarized light microscopy, indicating monosodium urate crystals that are typically seen in acute gouty arthritis. The synovial fluid was sterile in culture. His knee pain reduced significantly after arthrocentesis and non-steroidal anti-inflammatory drug treatment. To the best of our knowledge, this is the first description of an attack of acute gout following intraarticular injection of naturally derived hyaluronic acid. The possible mechanisms were discussed with a review of the relevant literature.

Gait Deviations in Patients with Early Osteoarthritis of the Knee

We design a case control study to evaluate the gait deviations of patients with early osteoarthritis(OA) of the knee, which are subtle and difficult to observe clinically. Twenty-six patients with symptomatic OA were recruited from the outpatient department. The control group consisted of 20 normal subjects who were matched for age, body weight, and body height. Both the patient and control groups were subjected to a similar protocol of gait analysis with comfortable speed. The peak value of angular displacement of pelvic tilt up, pelvic tilt down, knee valgus, ankle dorsifexion, and ankle rotation were significantly lower (p＜0.05) in the OA group. The peak angular displacement of knee varus of the OA group was significantly higher. The OA group also had significant higher peak moment in hip flexion, hip abduction, knee extension, knee valgus and plantarfiexion. However, the peak moment of knee flexion and varus were significantly lower than the control group. Patients tend to restrict the motion of ankle dorsiflexion, ankle rotation, and knee valgus to diminish pain. The decreased pelvic tilt up and down may also be due to the restricted motion of lower leg. The increased varus angular displacement is the result of varus deformity and ligamentous laxity, as a result of the long standing varus deformity of knee joint which transforms the mechanical axis of lower extremity and produces excess loading over the medial compartment. As the varus deformity increases, the valgus moment inevitably increases in order to achieve stability of knee joint during ambulation. The limited range of motion (ROM) at the end stage of knee extension may contribute to the increased extension moment of knee at stance phase to avoid buckling. This limitation of ROM also influences the ankle and hip joints, increasing the joint moment of plantarflexion, hip flexion and hip abduction. The OA group produces negative knee joint power and generate lower ankle joint power than the control group at pre-swing phase. Therefore, we can infer that the OA group can not generate power at pre-swing phase is due to poor propulsive force at pre-swing phase. In conclusion, patients with early osteoarthritis of knee joint have certain gait features during ambulation. The characteristic poor propulsion at pre-swing phase of knee and ankle joints could be an early sign of OA that may was used as a reference of clinical assessment.