Moe-Nilssen Rolf, Helbostad Jorunn L, Talcott Joel B, Toennessen Finn Egil
Department of Public Health and Primary Health Care, University of Bergen, Ulriksdal 8c, 5009, Bergen, Norway.
Exp Brain Res. 2003 May;150(2):237-44. doi: 10.1007/s00221-003-1450-4. Epub 2003 Apr 8.
Tests of postural stability have provided some evidence of a link between deficits in gross motor skills and developmental dyslexia. The ordinal-level scales used previously, however, have limited measurement sensitivity, and no studies have investigated motor performance during walking in participants with dyslexia. The purpose of this study was to investigate if continuous-scaled measures of standing balance and gait could discriminate between groups of impaired and normal readers when investigators were blind to group membership during testing. Children with dyslexia ( n=22) and controls ( n=18), aged 10-12 years, performed walking tests at four different speeds (slow-preferred-fast-very fast) on an even and an uneven surface, and tests of unperturbed and perturbed body sway during standing. Body movements were registered by a triaxial accelerometer over the lower trunk, and measures of reaction time, body sway, walking speed, step length and cadence were calculated. Results were controlled for gender differences. Tests of standing balance with eyes closed did not discriminate between groups. All unperturbed standing tests with eyes open showed significant group differences ( P<0.05) and classified correctly 70-77.5% of the subjects into their respective groups. Mean walking speed during very fast walking on both flat and uneven surface was > or =0.2 m/s ( P< or =0.01) faster for controls than for the group with dyslexia. This test classified 77.5% and 85% of the subjects correctly on flat and uneven surface, respectively. Cadence at preferred or very fast speed did not differ statistically between groups, but revealed significant group differences when all subjects were compared at a normalised walking speed ( P< or =0.04). Very fast walking speed as well as cadence at a normalised speed discriminated better between groups when subjects were walking on an uneven surface compared to a flat floor. Continuous-scaled walking tests performed in field settings may be suitable for motor skill assessment as a component of a screening tool for developmental dyslexia.
姿势稳定性测试提供了一些证据，证明粗大运动技能缺陷与发育性阅读障碍之间存在联系。然而，先前使用的顺序量表测量敏感性有限，且尚无研究调查阅读障碍参与者在行走过程中的运动表现。本研究的目的是调查，当测试人员在测试过程中对参与者所属组别不知情时，连续量表测量的站立平衡和步态能否区分阅读障碍组和正常阅读组。10至12岁的阅读障碍儿童（n = 22）和对照组儿童（n = 18）在平坦和不平坦的表面上以四种不同速度（慢-偏好-快-非常快）进行行走测试，并进行站立时未受干扰和受干扰的身体摆动测试。通过三轴加速度计记录下躯干的身体运动，并计算反应时间、身体摆动、步行速度、步长和步频的测量值。对结果进行了性别差异控制。闭眼站立平衡测试无法区分两组。所有睁眼未受干扰的站立测试均显示出显著的组间差异（P < 0.05），并将70 - 77.5%的受试者正确分类到各自的组中。在平坦和不平坦表面上进行非常快速行走时，对照组的平均步行速度比阅读障碍组快≥0.2 m/s（P ≤ 0.01）。该测试在平坦和不平坦表面上分别将77.5%和85%的受试者正确分类。偏好速度或非常快速时的步频在两组之间没有统计学差异，但当所有受试者以标准化步行速度进行比较时，显示出显著的组间差异（P ≤ 0.04）。与平坦地面相比，当受试者在不平坦表面行走时，非常快速的步行速度以及标准化速度下的步频在区分两组时表现更好。在实地环境中进行的连续量表行走测试可能适合作为发育性阅读障碍筛查工具的一部分进行运动技能评估。
