P. Taghavi Azar Sharabiani, D. Jafari, F. N. Mazhar, Bone and Joint Reconstruction Research Center, Iran University of Medical Sciences, Tehran, Iran P. Taghavi Azar Sharabiani, Shafa Yahyaian Hospital, Tehran, Iran H. Mehdizadeh, Department of Occupational Therapy, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran S. Brumagne, Department of Rehabilitation Sciences, KU Leuven, Leuven, Belgium S. Brumagne, Department of Physical Medicine and Rehabilitation, University Hospitals Leuven, Leuven, Belgium M. Davoudi, M. Parnianpour, Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran S. Rostami, S. Jamali, G. Taghizadeh, Rehabilitation Research Center, Department of Occupational Therapy, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran K. Khalaf, Department of Biomedical Engineering, Khalifa University of Science, Abu Dhabi, UAE.
Clin Orthop Relat Res. 2019 Jul;477(7):1659-1671. doi: 10.1097/CORR.0000000000000788.
Although impaired postural control may be a risk factor for distal radius fractures (wrist fractures), which often are caused by falls, little attention has been given thus far to the various performance and neurophysiologic aspects involved. Although studies suggest that external focus and cognitive tasks can improve postural control, it remains unclear whether these benefits are observed in individuals with a history of distal radius fracture and to what extent.
QUESTIONS/PURPOSES: (1) To compare patients with a history of distal radius fracture to age- and sex-matched controls in terms of postural stability while standing on stable and unstable support surfaces, using both postural sway and neurophysiological measures as endpoints; and (2) to determine whether internal- and external-focus strategies and cognitive tasks can improve postural stability in these patients.
Forty patients with distal radius fracture (33 females and seven males with a mean ± SD age of 56 ± 4 years) and 40 sex- and age-matched control participants participated in the study. We recruited patients with a history of fall-induced distal radius fractures occurring between 6 and 24 months before the start of our study. We excluded patients who had any of the following: fear of falling, taking any medication that may affect balance, neurologic disorders, dizziness, vestibular problems, Type II diabetes, musculoskeletal disorders or recent history of lower extremity fracture, any recent surgical interventions in the spine or lower limbs, and/or cognitive impairment. Of 120 patients who were being treated for distal radius fracture over the 18-month period, 91 (76%) agreed to participate and 40 eligible patients were finally enrolled. The control group included sex- and age-matched (within 2-year intervals) individuals who had never had a wrist fracture. This group was selected from attendants/relatives of the patients attending the neurology and physical medicine and rehabilitation outpatient departments, as well as other volunteers with no history of balance problems or wrist fractures. To address our primary research question, we compared the postural control of individuals with a history of distal radius fracture with the control group while quietly standing on different support surfaces (rigid and foam surfaces) using both postural sway measures obtained by a force plate as well as neurophysiological measures (electromyography [EMG] activity of tibialis anterior and medial gastrocnemius). To address our secondary research question, we compared the postural sway measures and EMG activity of the ankle muscles between different experimental conditions (baseline, internal focus (mentally focusing on their feet without looking), external focus (mentally focusing on rectangular papers, placed on the force plate or foam, one under each foot), difficult cognitive task (recalling maximum backward digits plus one) and easy cognitive task (recalling half of the maximum backward digits).
Patients with distal radius fractures presented with greater postural sway (postural instability) and enhanced ankle muscle activity compared with their control counterparts, but only while standing on a foam surface (mean velocity: 5.4 ± 0.8 versus 4.80 ± 0.5 [mean difference = 0.59, 95% CI of difference, 0.44-0.73; p < 0.001]; EMG root mean square of the tibialis anterior: 52.2 ± 9.4 versus 39.30 ± 6 [mean difference = 12.9, 95% CI of difference, 11.4-14.5; p < 0.001]). Furthermore, a decrease in postural sway was observed while standing on both rigid and foam surfaces during the external focus, easy cognitive, and difficult cognitive conditions compared with the baseline (for example, mean velocity in the baseline condition compared with external focus, easy cognitive task and difficult cognitive task was: 4.9 ± 1.1 vs 4.7 ± 1 [mean difference = 0.14, 95% CI of difference, 0.11-0.17; p < 0.001], 4.6 ± 1 [mean difference = 0.25, 95% CI of difference, 0.21-0.29; p < 0.001], and 4.5 ± 1 [mean difference = 0.34, 95% CI of difference, 0.29-0.40; p < 0.001] in the wrist fracture group). The same result was obtained for muscle activity while standing on foam (EMG root mean square of tibialis anterior in the baseline condition compared with external focus, easy cognitive task and difficult cognitive task: 58.8 ± 7.2 versus 52.3 ± 6.6 [mean difference = 6.5, 95% CI of difference, 5.5-7.6; p < 0.001], 48.8 ± 7.1 [mean difference = 10.1, 95% CI of difference, 9-11.1; p < 0.001], 42.2 ± 5.3 [mean difference = 16.7 95% CI of difference, 15.1-18.2; p < 0.001] in the wrist fracture group).
The current results suggest that patients with a history of distal radius fractures have postural instability while standing on unstable support surfaces. This instability, which is associated with enhanced ankle muscle activity, conceivably signifying an inefficient cautious mode of postural control, is alleviated by external attention demands and concurrent cognitive tasks.
The findings of this study may serve as a basis for designing informed patient-specific balance rehabilitation programs and strategies to improve stability and minimize falls in patients with distal radius fractures. The integrative methodology presented in this work can be extended to postural control and balance assessment for various orthopaedic/neurological conditions.
虽然姿势控制受损可能是桡骨远端骨折（腕部骨折）的一个危险因素，而这些骨折通常是由跌倒引起的，但迄今为止，人们对涉及的各种表现和神经生理方面关注甚少。尽管研究表明，外部焦点和认知任务可以改善姿势控制，但目前尚不清楚这些益处是否在桡骨远端骨折病史的个体中观察到，以及在何种程度上观察到。
问题/目的：（1）比较有桡骨远端骨折病史的患者与年龄和性别匹配的对照组在稳定和不稳定支撑表面上站立时的姿势稳定性，使用姿势摆动和神经生理测量作为终点；（2）确定内部和外部焦点策略和认知任务是否可以改善这些患者的姿势稳定性。
40 名桡骨远端骨折患者（33 名女性和 7 名男性，平均年龄±标准差为 56±4 岁）和 40 名年龄和性别匹配的对照组参与者参加了这项研究。我们招募了在我们的研究开始前 6 至 24 个月内因跌倒导致桡骨远端骨折的患者。我们排除了有以下任何一种情况的患者：害怕跌倒、服用任何可能影响平衡的药物、神经系统疾病、头晕、前庭问题、2 型糖尿病、肌肉骨骼疾病或近期下肢骨折史、最近在脊柱或下肢进行的任何手术干预，以及/或认知障碍。在 18 个月的时间里，有 120 名桡骨远端骨折患者接受治疗，其中 91 名（76%）同意参与，最终有 40 名符合条件的患者入选。对照组包括与患者性别和年龄匹配（在 2 年间隔内）且从未有过手腕骨折的个体。该组是从患者在神经科和物理医学和康复门诊就诊的家属/亲属以及其他没有平衡问题或手腕骨折史的志愿者中选择的。为了回答我们的主要研究问题，我们比较了桡骨远端骨折患者与对照组在不同支撑表面（刚性和泡沫表面）上安静站立时的姿势控制，使用力板获得的姿势摆动测量值以及神经生理测量值（胫骨前肌和内侧腓肠肌的肌电图[EMG]活动）。为了回答我们的次要研究问题，我们比较了不同实验条件下（基线、内部焦点（不看脚而专注于脚）、外部焦点（专注于放置在力板或泡沫上的矩形纸，每只脚下一个）、困难认知任务（回忆最大回拨数字加 1）和简单认知任务（回忆最大回拨数字的一半）下的姿势摆动测量值和踝关节肌肉的 EMG 活动。
桡骨远端骨折患者与对照组相比，站立在泡沫表面时表现出更大的姿势摆动（姿势不稳定）和增强的踝关节肌肉活动，但仅在泡沫表面上（平均速度：5.4±0.8 与 4.80±0.5[平均差异=0.59，95%置信区间的差异，0.44-0.73；p<0.001]；胫骨前肌的 EMG 均方根：52.2±9.4 与 39.30±6[平均差异=12.9，95%置信区间的差异，11.4-14.5；p<0.001]）。此外，与基线相比，在刚性和泡沫表面上，外部焦点、简单认知和困难认知条件下，站立时的姿势摆动减少（例如，与外部焦点、简单认知任务和困难认知任务相比，在基线条件下的平均速度是：4.9±1.1 与 4.7±1[平均差异=0.14，95%置信区间的差异，0.11-0.17；p<0.001]，4.6±1[平均差异=0.25，95%置信区间的差异，0.21-0.29；p<0.001]，4.5±1[平均差异=0.34，95%置信区间的差异，0.29-0.40；p<0.001]）。在泡沫上的肌肉活动也得到了相同的结果（在基线条件下，胫骨前肌的 EMG 均方根与外部焦点、简单认知任务和困难认知任务相比：58.8±7.2 与 52.3±6.6[平均差异=6.5，95%置信区间的差异，5.5-7.6；p<0.001]，48.8±7.1[平均差异=10.1，95%置信区间的差异，9-11.1；p<0.001]，42.2±5.3[平均差异=16.7，95%置信区间的差异，15.1-18.2；p<0.001]）。
目前的结果表明，桡骨远端骨折患者在站立于不稳定支撑表面时姿势不稳定。这种不稳定，与增强的踝关节肌肉活动相关，可能表明姿势控制的低效谨慎模式，通过外部注意力需求和并发认知任务得到缓解。
本研究的结果可以为设计针对桡骨远端骨折患者的有针对性的平衡康复计划和策略提供依据，以改善稳定性并减少跌倒。本研究中采用的综合方法可以扩展到各种骨科/神经科疾病的姿势控制和平衡评估。
