A New Communication Device Using the Anal Sphincter

OBJECTIVE: The purpose of this study was to invent a new communication device by utilizing the function of anal sphincter muscles that was another residual motor function to the last in amyotrophic lateral sclerosis (ALS) patients. METHOD: We designed a sensor which worked by changing intensity of the contraction and was enable severely paralyzed patients to communicate by means of self-regulation of the anal sphincter contraction. This device made sentences through combination of selected Korean letters deprived from sphincter contractions. RESULTS: This device was composed of three parts. Anal sensor: the head part of the sensor regulated by sphincters was located in the rectum, signal processing module: the raw signal from the sensor was boosted up and set up on the baseline voltage equal to threshold by threshold detector, and device program: the icon mode which was composed of routine questions and requested to their care-givers. And in user-writing mode, patients could choose syllable elements using the sensor operating by sphincter. CONCLUSION: This system was designed for advanced ALS patients with only the available function of sphincter muscles and could give them another new option in selecting communication devices.

Respiratory Muscle Strength and Cough Capacity in Patients with Duchenne Muscular Dystrophy

The function of inspiratory muscles is crucial for effective cough as well as expiratory muscles in patients with Duchenne muscular dystrophy (DMD). However, there is no report on the correlation between cough and inspiratory muscle strength. To investigate the relationships of voluntary cough capacity, assisted cough techniques, and inspiratory muscle strength as well as expiratory muscle strength in patients with DMD (n=32). The vital capacity (VC), maximum insufflation capacity (MIC), maximal inspiratory pressure (MIP), and maximal expiratory pressure (MEP) were measured. Unassisted peak cough flow (UPCF) and three different techniques of assisted PCF were evaluated. The mean value of MICs (1918 +/- 586 mL) was higher than that of VCs (1474 +/- 632 mL) (p < 0.001). All three assisted cough methods showed significantly higher value than unassisted method (212 +/- 52 L/min) (F = 66.13, p < 0.001). Combined assisted cough technique (both manual and volume assisted PCF; 286 +/- 41 L/min) significantly exceeded manual assisted PCF (MPCF; 246 +/- 49 L/ min) and volume assisted PCF (VPCF; 252 +/- 45 L/min) (F = 66.13, p < 0.001). MIP (34 +/- 13 cmH2O) correlated significantly with both UPCF and all three assisted PCFs as well as MEP (27 +/- 10 cmH2O) (p < 0.001). Both MEP and MIP, which are the markers of respiratory muscle weakness, should be taken into account in the study of cough effectiveness.

Concentric and Eccentric Isokinetic Trunk Muscle Evaluation in Chronic Low Back Pain

OBJECTIVE: The purpose of this study is to evaluate concentric and eccentric trunk muscle strength in patients with chronic low back pain and compare it with healthy controls to determine the role of trunk muscle in chronic low back pain METHOD: Subjects were 20 chronic low back pain patients with the duration at least 6 months and 20 normal adults. Concentric and eccentric isokinetic trunk muscle test was performed at specific speeds (30degrees, 60degrees, 120degrees/sec) with Cybex 770 machine in back pain patients and healthy control. RESULTS: The strength of trunk flexor and extensor muscles of chronic low back pain patients was significantly weaker than that of normal controls. Eccentric peak torque was significantly higher than concentric peak torque in both patients and healthy control. A concentric and eccentric ratio of patients was lower than that of normal controls. The correlation between concentric and eccentric variables was high. Our results show that concentric peak torque has the highest correlation with eccentric peak torque. CONCLUSION: Isokinetic evaluations of the trunk muscle offer objective and quantitative data of patients with chronic low back pain and will be clinically useful in muscle power measurement of lumbar muscles.

The Effects of Rehabilitative Training in the Treatment of Patellofemoral Pain Syndrome

OBJECTIVE: Inappropriate neural control of the quadriceps femoris muscle group has been implicated in patellofemoral pain syndrome (PFPS) and the methods of biomechanical assessment of PFPS has been developed recently. The aims of the present investigation were to evaluate the effects of therapeutic exercise in the alleviation of PFPS and to develope objective clinical test for PFPS. METHOD: We investigated the onset time of the isometric contraction of vastus medialis oblique muscle (VMO) and the vastus lateralis muscle (VL) under four different conditions: knee flexion and extension in weight bearing (standing) and non-weight bearing (sitting on chair) situations. For each condition, onset times of EMG activities and onset times for VMO and VL were determined from five trials of isometric contraction. In addition, we compared knee flexor and extensor torques in control group and subjects with PFPS. To evaluate the effects of the exercise we compared the onset time difference (onset time of VL-onset time of VM) and quadriceps muscle torque at pre- and post- exercise in PFPS groups. RESULTS: In PFPS group, onset time of VMO during knee extension was significantly longer than the onset time of VL and the knee extensor torque was considerably weaker in comparison with normal group. Although onset time difference was not changed after exercise program, there were significant increase in knee extensor torque in subjects with PFPS. CONCLUSION: The role of exercise in the rehabilitation of quadriceps functions is to reduce the pain, to strengthen the knee extensor, and further accurate diagnostic tools and methods for the result of therapeutic exercise in PFPS are needed.