Conference Presentations by Ping Yeap Loh
The effect of wrist flexion and extension on median nerve at carpal tunnel among elderly Japanese men
Effect of Wrist Angle on the Median Nerve Shape at Proximal Carpal Tunnel
Median Nerve Displacement at Passive Wrist Positions
The Comparison of Median Nerve Circularity between Active and Passive Wrist Positions at Wrist Region
ABSTRACT
Carpal tunnel syndrome (CTS) is one of the most common work-related musculoskeletal dis... more ABSTRACT
Carpal tunnel syndrome (CTS) is one of the most common work-related musculoskeletal disorders of the upper extremities which median nerve at the wrist carpal tunnel region is affected. Workers perform active and passive joint holding in their daily working environment such as wrist active holding (AH) during manual lifting task and wrist passive holding (PH) resting during computer typing. Therefore, median nerve compression may be affected by different active and passive wrist holding positions. The objective of this study is to understand the effects of wrist active and passing holding positions on the changes of the median nerve circularity at different wrist angle positions. Methods: Eight right-handed healthy male adults (age 27.0 ± 3.5 years; height 171.6 ± 6.2 cm) were recruited for this study. Ultrasound (US) examination for median nerve were performed with GE Healthcare Ultrasound System (LOGIQ e) with a 6-13mHz transducer (Model 12L-RS) and gel pad was used as coupling medium for US examination. Three wrist positions were examined and repeated for both wrist AH and PH, comprising wrist neutral (WN)0°, wrist extension (WE)30° and wrist flexion (WF)30°. The longitudinal and vertical diameter of the median nerve were used to calculate the MNCSA and circularity. Results: MNCSA was significantly smaller at WE30 °, WF30 ° compared to WN for both dominant and non-dominant hand at AH and PH positions (p < 0.001). Meanwhile, the median nerve circularity decreased significantly from WN to WE30° (p < 0.001) and increased significantly from WN to WF30° (p < 0.001) for both AH and PH positions. However, wrist AH and PH did not showed significant effect on MNCSA and circularity changes at different wrist positions. Conclusion: The results indicated that WE/WF caused significant reduction of MNCSA and median nerve circularity changed significantly compared to WN regardless to AH/PH positions.
Keywords: Median Nerve Cross-sectional area, Ultrasound
Carpal tunnel syndrome (CTS) is one of the most common work-related musculoskeletal disorders of the upper extremities which median nerve at the wrist carpal tunnel region is affected. Workers perform active and passive joint holding in their daily working environment such as wrist active holding (AH) during manual lifting task and wrist passive holding (PH) resting during computer typing. Therefore, median nerve compression may be affected by different active and passive wrist holding positions. The objective of this study is to understand the effects of wrist active and passing holding positions on the changes of the median nerve circularity at different wrist angle positions. Methods: Eight right-handed healthy male adults (age 27.0 ± 3.5 years; height 171.6 ± 6.2 cm) were recruited for this study. Ultrasound (US) examination for median nerve were performed with GE Healthcare Ultrasound System (LOGIQ e) with a 6-13mHz transducer (Model 12L-RS) and gel pad was used as coupling medium for US examination. Three wrist positions were examined and repeated for both wrist AH and PH, comprising wrist neutral (WN)0°, wrist extension (WE)30° and wrist flexion (WF)30°. The longitudinal and vertical diameter of the median nerve were used to calculate the MNCSA and circularity. Results: MNCSA was significantly smaller at WE30 °, WF30 ° compared to WN for both dominant and non-dominant hand at AH and PH positions (p < 0.001). Meanwhile, the median nerve circularity decreased significantly from WN to WE30° (p < 0.001) and increased significantly from WN to WF30° (p < 0.001) for both AH and PH positions. However, wrist AH and PH did not showed significant effect on MNCSA and circularity changes at different wrist positions. Conclusion: The results indicated that WE/WF caused significant reduction of MNCSA and median nerve circularity changed significantly compared to WN regardless to AH/PH positions.
Keywords: Median Nerve Cross-sectional area, Ultrasound
The Effect of Different Wrist Positions on Median Nerve Cross-sectional Area at Proximal Carpal Tunnel Level
Background: Work-related musculoskeletal disorders (MSD) is known to be increasing among healthca... more Background: Work-related musculoskeletal disorders (MSD) is known to be increasing among healthcare industry employees such as nurses and sonographers. Carpal tunnel syndrome (CTS) is one of the most common MSD. Awkward wrist joint posture and repetitive wrist joint movement are recognized as high-risk causes to CTS. The effects of mechanical stress caused by different wrist angles on the median nerve may lead to peripheral nerve compression syndrome. Better wrist position for daily work routine can be identified through the understanding of the median nerve cross-sectional area (MNCSA) as it changes in different wrist positions. The objective of this study is to investigate the effect of different wrist positions on the MNCSA at proximal carpal tunnel level.
Methods: Twelve right-handed healthy male students (age 24.2 ± 2.2 years; BMI 23.5 ± 5.6 kg/m2; wrist circumference 16.2 ± 1.6 cm for the right side and 16.0 ± 0.9 cm for the left side) were recruited for this study. All the participants were free from signs and symptoms of carpal tunnel syndrome as indicated from the screening and clinical examinations. This study was approved by Ethic Committee, Graduate School of Design, Kyushu University.
Ultrasound (US) examination were performed with GE Healthcare Ultrasound System (Model LOGIQ e) with a 6-13mHz transducer (Model 12L-RS) and gel pad (thickness 7.0 mm; Sonar Pad, Nippon BXI Inc., Japan) was used as coupling medium for US examination.
Participants sat upright with their forearm resting on forearm support on a table during US examination. Median nerve was examined bilaterally at proximal carpal tunnel level in transverse plane. Pisiform bonymark was used as a landmark to proximal carpal tunnel during US examination. Seven wrist posi-tions were examined, comprising wrist neutral (0°), wrist extension 15°, 30°, 45° and wrist flexion 15°, 30°, 45°. Participants were instructed to relax the wrist and fingers during US examination.
Three ultrasound images were taken for each wrist position and the average from three measurements was calculated to represent the wrist angle respectively. MNCSA was measured by tracing method through ImageJ. MNCSA at wrist neutral was used as a reference point.
Results: The range of MNCSA at wrist neutral was 6.18 - 11.44 mm2 for the dominant hand and the range was 5.49 - 9.30 mm2 for the non-dominant hand. Paired t-test showed significant difference of MNCSA between the dominant hand (8.20 ± 1.55 mm2) and the non-dominant hand (7.31 ± 1.26 mm2) (p<0.01).
One-way repeated measures ANOVA was used to analyse the effect of wrist neutral changed into different wrist positions on MNCSA. There was signifi-cant effect when wrist changed to wrist extension on the MNCSA for both dominant and non-dominant hands (p<0.01). The mean values of MNCSA in dominant wrist extension at 15°, 30° and 45° are 7.78 ± 1.44 mm2, 7.07 ± 1.12 mm2 and 6.50 ± 1.04 mm2, respectively. For the dominant hand, post-hoc pairwise Bonferroni-corrected comparisons showed significant reduced in MNCSA for both wrist extension 30° and wrist extension 45° (p<0.01) com-pared to wrist neutral. However, there was no significant difference in wrist extension 15°. In contrast with the dominant hand, the MNCSA mean values for non-dominant wrist extension 15°, 30° and 45° are 7.06 ± 1.31 mm2, 6.43 ± 1.35 mm2 and 6.08 ± 1.23 mm2, respectively. When compared to wrist neutral, the MNCSA reduction for all three wrist extensions 15°, 30° and 45° were significant (p<0.01).
Similarly, the effect of wrist flexion caused on MNCSA for both the dominant hand and the non-dominant hand were significant (p<0.01). For the dominant hand, mean values of the MNCSA at wrist flexion 15°, 30° and 45° are 7.39 ± 1.51 mm2, 6.74 ± 0.97 mm2 and 6.29 ± 0.90 mm2, respectively. For non-dominant hand, mean values of the MNCSA at wrist flexion 15°, 30° and 45° are 7.04 ± 1.14 mm2, 6.48 ± 0.91 mm2 and 5.99 ± 1.06 mm2, respectively. The reduction in MNCSA by all wrist flexion were significant for both dominant and non-dominant hand (p<0.01).
A comparison of MNCSA percentage changes was made between dominant and non-dominant hand among different wrist positions with wrist neutral as reference point. When the wrist extension increased to 15°, 30° and 45°, the MNCSA reduction trend were approximately 6%, 14% and 21%, respectively for both dominant and non-dominant hand. Similar MNCSA reduction trend was observed for both dominant and non-dominant hand when wrist neutral changed into wrist flexion positions. However the reduction percentages were higher compare to wrist extension which were approximately 10%, 19% and 24%; at wrist flexion 15°, 30° and 45°.
Conclusion: The results indicated significant differences in MNCSA between dominant and non-dominant hands. Wrist neutral position showed larger MNCSA among all wrist positions. Wrist extension and flexion will cause MNCSA to be reduced compared to wrist neutral. In comparison, both dominant and non-dominant wrist flexion 45° and extension 45° showed higher MNCSA reduction percentage compared with other wrist positions.
Methods: Twelve right-handed healthy male students (age 24.2 ± 2.2 years; BMI 23.5 ± 5.6 kg/m2; wrist circumference 16.2 ± 1.6 cm for the right side and 16.0 ± 0.9 cm for the left side) were recruited for this study. All the participants were free from signs and symptoms of carpal tunnel syndrome as indicated from the screening and clinical examinations. This study was approved by Ethic Committee, Graduate School of Design, Kyushu University.
Ultrasound (US) examination were performed with GE Healthcare Ultrasound System (Model LOGIQ e) with a 6-13mHz transducer (Model 12L-RS) and gel pad (thickness 7.0 mm; Sonar Pad, Nippon BXI Inc., Japan) was used as coupling medium for US examination.
Participants sat upright with their forearm resting on forearm support on a table during US examination. Median nerve was examined bilaterally at proximal carpal tunnel level in transverse plane. Pisiform bonymark was used as a landmark to proximal carpal tunnel during US examination. Seven wrist posi-tions were examined, comprising wrist neutral (0°), wrist extension 15°, 30°, 45° and wrist flexion 15°, 30°, 45°. Participants were instructed to relax the wrist and fingers during US examination.
Three ultrasound images were taken for each wrist position and the average from three measurements was calculated to represent the wrist angle respectively. MNCSA was measured by tracing method through ImageJ. MNCSA at wrist neutral was used as a reference point.
Results: The range of MNCSA at wrist neutral was 6.18 - 11.44 mm2 for the dominant hand and the range was 5.49 - 9.30 mm2 for the non-dominant hand. Paired t-test showed significant difference of MNCSA between the dominant hand (8.20 ± 1.55 mm2) and the non-dominant hand (7.31 ± 1.26 mm2) (p<0.01).
One-way repeated measures ANOVA was used to analyse the effect of wrist neutral changed into different wrist positions on MNCSA. There was signifi-cant effect when wrist changed to wrist extension on the MNCSA for both dominant and non-dominant hands (p<0.01). The mean values of MNCSA in dominant wrist extension at 15°, 30° and 45° are 7.78 ± 1.44 mm2, 7.07 ± 1.12 mm2 and 6.50 ± 1.04 mm2, respectively. For the dominant hand, post-hoc pairwise Bonferroni-corrected comparisons showed significant reduced in MNCSA for both wrist extension 30° and wrist extension 45° (p<0.01) com-pared to wrist neutral. However, there was no significant difference in wrist extension 15°. In contrast with the dominant hand, the MNCSA mean values for non-dominant wrist extension 15°, 30° and 45° are 7.06 ± 1.31 mm2, 6.43 ± 1.35 mm2 and 6.08 ± 1.23 mm2, respectively. When compared to wrist neutral, the MNCSA reduction for all three wrist extensions 15°, 30° and 45° were significant (p<0.01).
Similarly, the effect of wrist flexion caused on MNCSA for both the dominant hand and the non-dominant hand were significant (p<0.01). For the dominant hand, mean values of the MNCSA at wrist flexion 15°, 30° and 45° are 7.39 ± 1.51 mm2, 6.74 ± 0.97 mm2 and 6.29 ± 0.90 mm2, respectively. For non-dominant hand, mean values of the MNCSA at wrist flexion 15°, 30° and 45° are 7.04 ± 1.14 mm2, 6.48 ± 0.91 mm2 and 5.99 ± 1.06 mm2, respectively. The reduction in MNCSA by all wrist flexion were significant for both dominant and non-dominant hand (p<0.01).
A comparison of MNCSA percentage changes was made between dominant and non-dominant hand among different wrist positions with wrist neutral as reference point. When the wrist extension increased to 15°, 30° and 45°, the MNCSA reduction trend were approximately 6%, 14% and 21%, respectively for both dominant and non-dominant hand. Similar MNCSA reduction trend was observed for both dominant and non-dominant hand when wrist neutral changed into wrist flexion positions. However the reduction percentages were higher compare to wrist extension which were approximately 10%, 19% and 24%; at wrist flexion 15°, 30° and 45°.
Conclusion: The results indicated significant differences in MNCSA between dominant and non-dominant hands. Wrist neutral position showed larger MNCSA among all wrist positions. Wrist extension and flexion will cause MNCSA to be reduced compared to wrist neutral. In comparison, both dominant and non-dominant wrist flexion 45° and extension 45° showed higher MNCSA reduction percentage compared with other wrist positions.
Deformation of Median Nerve during Active and Passive Wrist Holding at Proximal Carpal Tunnel
The first objective of this study was to identify the deformation of the median nerve cross-secti... more The first objective of this study was to identify the deformation of the median nerve cross-sectional area (MNCSA) at different wrist active and passive holding positions. The second objective was to compare the wrist circumference, wrist width, and wrist depth between dominant and non-dominant hands. A total of eight right-handed healthy male adults (age 27.0 ±3.5 years) participated in this study. Ultrasound examination was performed at the proximal carpal tunnel to examine the median nerve on the transverse plane. A total of three wrist positions were examined, namely, wrist neutral, wrist flexion 30°, and wrist extension 30°, in active and passive holding positions for both dominant and non-dominant hands. Paired t-test showed significant differences between dominant (D) and non-dominant (ND) hands in wrist circumference, wrist width, and wrist depth (D = 39.6 ± 2.8 mm, ND = 38.3 ± 2.7 mm, p<0.01). The differences of MNCSA between dominant and non-dominant hands were significant (p<0.001) at both active (D = 7.93 ± 0.63 mm2, ND = 6.98 ± 0.42 mm2) and passive holding positions (D = 8.22 ± 0.72 mm2, ND = 7.06 ± 0.44 mm2). Two-way repeated-measures ANOVA showed that wrist flexion 30° and wrist extension 30°caused significant reductions in MNCSA when compared with wrist neutral (p<0.001) in both active and passive holding positions.
Effect of Wrist Deviation on Median Nerve Cross -Sectional Area at Proximal Carpal Tunnel Level
Characteristics of Walking Motion In Elderly Japanese Women
Walking is one of the most fundamental actions in life, and changes in gait are associated with t... more Walking is one of the most fundamental actions in life, and changes in gait are associated with the aging process. The assessment of walking motion is important to prevent deterioration in walking ability, and three-dimensional (3D) motion analysis can be used to observe the different parameters of walking motion. This study investigated the gait characteristics at two different speed conditions among elderly Japanese women and analyzed the relationship between aging and gait parameters. Forty elderly Japanese women (mean age, 73.9 ± 4.8 years) were observed walking barefoot on a flat surface for 10 m at self-selected and fast speeds, with 3 trials at each speed. Using a 3D motion analysis system, basic gait parameters (walking speed, step length, difference between right and left step lengths, ratio of step length to height, ratio of step length to lower-limb length, cadence, and walk ratio) and gait cycle parameters (time of swing and stance phase, duration of one gait cycle, and percentage of swing and stance phase) were measured. The mean values of the walking speed, step length, and cadence of elderly Japanese women were 72.7 ± 8.0 m/min, 58.4 ± 4.3 cm, and 122.7 ± 9.3 steps/min at self-selected speed conditions, and 88.6 ± 9.4 m/min, 63.6 ± 5.7 cm, and 137.5 ± 13.5 steps/min at fast speed conditions, respectively. Step length was inversely correlated with age (p < 0.01) for both speed conditions. In conclusion, step length can be used as a major characteristic to observe aging-related changes in walking motion among elderly Japanese women.
Papers by Ping Yeap Loh
Median nerve behavior at different wrist positions among older males
The effect of wrist flexion-extension on the median nerve appearance, namely the cross-sectional ... more The effect of wrist flexion-extension on the median nerve appearance, namely the cross-sectional area (MNCSA) and the longitudinal (D1) and vertical (D2) diameters, was investigated among older adults (N = 34). Ultrasound examination was conducted to examine the median nerve at different wrist angles (neutral; and 15°, 30°, and 45° extension and flexion), in both the dominant and nondominant hand. Median nerve behavior were significantly associated with wrist angle changes. The MNCSA at wrist flexion and extension were significantly smaller (P < .001) compared with the neutral position in both the dominant and nondominant hand. The D1 and D2 were significantly reduced at flexion (P < .001) and extension (P < .001), respectively, in both the dominant and nondominant hand. Our results suggest that a larger flexion-extension angle causes higher compression stress on the median nerve, leading to increased deformation of the MNCSA, D1, and D2 among older adults.
Effect of Wrist Angle on Median Nerve Appearance at the Proximal Carpal Tunnel
This study investigated the effects of wrist angle, sex, and handedness on the changes in the med... more This study investigated the effects of wrist angle, sex, and handedness on the changes in the median nerve cross-sectional area (MNCSA) and median nerve diameters, namely longitudinal diameter (D1) and vertical diameter (D2). Ultrasound examination was conducted to examine the median nerve at the proximal carpal tunnel in both dominant and nondominant hands of men (n = 27) and women (n = 26). A total of seven wrist angles were examined: neutral; 15°, 30°, and 45° extension; and 15°, 30°, and 45° flexion. Our results indicated sexual dimorphism and bilateral asymmetry of MNCSA, D1 and D2 measurements. MNCSA was significantly reduced when the wrist angle changed from neutral to flexion or extension positions. At flexion positions, D1 was significantly smaller than that at neutral. In contrast, at extension positions, D2 was significantly smaller than that at neutral. In conclusion, this study showed that MNCSA decreased as the wrist angle changed from neutral to flexion or extension positions in both dominant and nondominant hands of both sexes, whereas deformation of the median nerve differed between wrist flexion and extension.
Effect of wrist deviation on median nerve cross-sectional area at proximal carpal tunnel level
Median Nerve Displacement at Passive Wrist Positions
Effects of Increased Step Length on Walking Motion
In Japanese
Exploratory Investigation of Gait Parameters Changed with Aging among Older Adults
In Japanese