Biomedical subjects

Kris W N Wong

Publications and source records attributed to Kris W N Wong.

3 recordsLinked to original sources

PubMed2006

Continuous dynamic spinal motion analysis.

STUDY DESIGN: Continuous dynamic lumbar intervertebral flexion-extension is assessed by a videofluoroscopy with a new auto-tracking system. OBJECTIVES: To develop and validate a new method for the continuous assessment of lumbar kinematics. SUMMARY OF BACKGROUND DATA: Instability of the lumbar spine is thought to be associated with low back pain, but the diagnosis remains difficult. Functional radiographs have been used for diagnosis of spinal instability but error and limitation exist, whereas videofluoroscopy provides a cost-effective way for such analysis. However, common approaches of image analysis of videofluoroscopic video are tedious and time-consuming because of the low quality of the images. Physicians have to extract the vertebrae manually in most cases; thus, continuous motion analysis is hardly achieved. METHODS: A new system that can perform automatic vertebrae segmentation and tracking is developed. In vitro and in vivo validity were evaluated. Intervertebral flexion and extension was assessed in 30 healthy volunteers. RESULTS: In vitro and in vivo validity tests have been conducted with good results. A linear-liked pattern of the intervertebral flexion-extension (IVFE) curves in different levels was found, and the IVFE decreased in descending order from L1-L5 at different points of range of motion in flexion. Conversely, extension is evenly contributed at different levels, and the concavity of lumbar lordosis increases steadily in backward movement. CONCLUSIONS: The newly developed technique in assessing the dynamic lumbar motion is reliable and able to analyze the lumbar intervertebral movement from videofluoroscopic images automatically and accurately. The proposed system requires less human intervention than common approaches. It may have a potential value in the evaluation of spinal "instability" in clinical practice.

Adult↗

PubMed2004

The flexion-extension profile of lumbar spine in 100 healthy volunteers.

STUDY DESIGN: Dynamic lumbar flexion-extension motions were assessed by an electrogoniometer and a videofluoroscopy unit simultaneously. OBJECTIVES: The aims of this study were to assess the motion profile of lumbar spine in different genders and age groups and to assess their differences. SUMMARY OF BACKGROUNDS DATA: The dynamic lumbar flexion-extension motions analysis method has been developed and validated. However, data profile of the spinal motions of healthy volunteers has not been established. METHODS.: A total of 100 healthy volunteers, including 50 men and 50 women, were recruited. They were then divided into four equal groups, following their age ranges of 21 to 30 years, 31 to 40 years, 41 to 50 years, and 51 years and older. Lumbar flexion-extension motion was assessed with an electrogoniometer and videofluoroscopy simultaneously. Radiologic images of the lumbar spine were captured during flexion-extension in 10 degrees intervals. Intervertebral flexion-extension (IVFE) of each vertebral level was calculated. The spinal motion of different genders was compared segment by segment with independent t test. The spinal motion of different age groups was compared with one-way analysis of variance. RESULTS: A linear-liked pattern of the IVFE curves was observed in different genders and age groups. No statistically significant difference in the pattern of motion was found between genders. However, statistically significant difference in the slope of IVFE curves was found at all lumbar levels in subjects whose age was 51 years or older (P < 0.05). CONCLUSIONS: Assessment of motion profile was found to be helpful for the identification of spinal disorders in clinical practice. Because of the normal variation of spinal motion of subjects in different age ranges, interpretation of spinal motion disorders should be careful. Although the sample size in this study was limited, the database generated might be useful to assist the diagnosis of spinal "instability" in the future.

Adult↗

PubMed2002

Development and validation of a new technique for assessing lumbar spine motion.

STUDY DESIGN: Dynamic lumbar flexion-extension motions were assessed by an electrogoniometer and a videofluoroscopy unit simultaneously. OBJECTIVE: To develop and validate a new technique for the assessment of lumbar spine motion. SUMMARY OF BACKGROUND DATA: Spine instability, a clinical condition that is common but difficult to diagnose, has been suggested to involve a characteristic change in the relation between vertebrae during motion. Assessment of lumbar instability using functional radiographs is controversial. Information regarding dynamic spine kinematics in vivo is limited. METHODS: A lumbar spine motion analysis system was developed, and its reliability was assessed. Simultaneous total flexion range of motion and segmental motion of the lumbar spine were assessed in 30 healthy volunteers. Lumbar images were captured in 10 degrees intervals during flexion-extension. Intervertebral flexion-extension of each vertebral level was calculated. RESULTS: In flexion, the lumbar vertebrae flexed with a descending order from L1 to L5 throughout the motion. Conversely, the concavity of lumbar lordosis increased steadily in extension. No statistically significant difference in the pattern of motion was found between genders. CONCLUSIONS: The results from this study showed that the newly developed technique is reliable. It may have potential value for evaluating spine instability in clinical practice.

Adult↗