Standing balance: a comparison between idiopathic and whiplash-induced neck pain

Disturbances of balance have been found both in patients with whiplash-associated disorders and idiopathic neck pain. This study directly compared balance between these groups to determine if neck pain precipitated by trauma resulted in greater or different balance impairments. The study was a comparative, observational design. Thirty subjects with whiplash, 30 with idiopathic neck pain and 30 healthy controls, took part in the study. Subjects performed balance tests in comfortable, narrow and tandem stances. Balance disturbances (sway energy and/or root mean squared (RMS) amplitude) were evident in several tests between subjects with neck pain and controls. Direct comparison between the neck pain groups revealed that the whiplash group had significantly greater sway energy and RMS amplitude than the idiopathic group in comfortable stance tests on a soft surface (F > 4.4, p < 0.04). Further, the whiplash group had greater RMS, but significantly less sway energy than the idiopathic group in most narrow stance tests in the anterior posterior direction F > 5.8, p < 0.02). Both neck pain groups were also significantly less able to complete the eyes closed, tandem test compared to control subjects. In conclusion, the study has found that balance deficits exist in both subjects with whiplash-associated disorders and idiopathic neck pain compared to controls; however, differences in balance strategies may exist between the neck pain groups. Overall, subjects who have experienced trauma appear to have greater balance disturbances.     

Smooth pursuit neck torsion test in whiplash-associated disorders: relationship to self-reports of neck pain and disability, dizziness and anxiety.

OBJECTIVE: The smooth pursuit neck torsion test is thought to be a measure of neck afferent influence on eye movement control and is useful in assessing subjects with whiplash, especially those complaining of dizziness. Nevertheless, it is not known whether impairments identified relate only to abnormal cervical afferentation or are influenced by levels of anxiety or neck pain. DESIGN: A prospective, 3-group, observational design. SUBJECTS: One hundred subjects with persistent whiplash (50 complaining of dizziness, 50 not complaining of dizziness) and 50 healthy controls. METHODS: The smooth pursuit neck torsion test was performed and analysed taking into account subjects' reported levels of pain, anxiety and dizziness. RESULTS: The results confirm that there are significant (p<0.01) differences in the smooth pursuit neck torsion test between subjects with persistent whiplash both with dizziness (mean 0.11) and without dizziness (mean 0.07) compared with healthy control subjects (mean 0.01). The results suggest that the test is not influenced by a patients' level of anxiety, but may be influenced by both nocioceptive and proprioceptive factors. CONCLUSION: The results provide further evidence of the usefulness of the smooth pursuit neck torsion test to identify eye movement disturbances in patients with whiplash, which are likely to be due to disturbed cervical afferentation.     

Dynamic and functional balance tasks in subjects with persistent whiplash: a pilot trial

Disturbances in static balance have been demonstrated in subjects with persistent whiplash. Some also report loss of balance and falls. These disturbances may contribute to difficulties in dynamic tasks. The aim of this study was to determine whether subjects with whiplash had deficits in dynamic and functional balance tasks when compared to a healthy control group. Twenty subjects with persistent pain following a whiplash injury and twenty healthy controls were assessed in single leg stance with eyes open and closed, the step test, Fukuda stepping test, tandem walk on a firm and soft surface, Singleton test with eyes open and closed, a stair walking test and the timed 10 m walk with and without head movement. Subjects with whiplash demonstrated significant deficits (p < 0.01) in single leg stance with eyes closed, the step test, tandem walk on a firm and soft surface, stair walking and the timed 10 m walk with and without head movement when compared to the control subjects. Specific assessment and rehabilitation directed towards improving these deficits may need to be considered in the management of patients with persistent whiplash if these results are confirmed in a larger cohort.     

The effect of neck torsion on postural stability in subjects with persistent whiplash

Dysfunction of cervical receptors in neck disorders has been shown to lead to disturbances in postural stability. The neck torsion manoeuvre used in the smooth pursuit neck torsion (SPNT) test is thought to be a specific measure of neck afferent dysfunction on eye movement in those with neck pain. This study aimed to determine whether neck torsion could change balance responses in those with persistent whiplash-associated disorders (WADs). Twenty subjects with persistent WAD and 20 healthy controls aged between 18 and 50 years stood on a computerised force plate with eyes closed in comfortable stance under 5 conditions: neutral head, head turned to left and right and neck torsion to left and right. Root mean square (rms) amplitude of sway was measured in the anterior-posterior (AP) and medial-lateral (ML) directions. The whiplash group had significantly greater rms amplitude in the AP direction following neck torsion compared to the control group (p < 0.03). The results show that the neck torsion manoeuvre may lead to greater postural deficits in individuals with persistent WAD and provides further evidence of neck torsion to identify abnormal cervical afferent input, as an underlying cause of balance disturbances in WAD. Further research is warranted.     

Head repositioning accuracy to neutral: a comparative study of error calculation

Deficits in cervical proprioception have been identified in subjects with neck pain through the measure of head repositioning accuracy (HRA). Nevertheless there appears to be no general consensus regarding the construct of measurement of error used for calculating HRA. This study investigated four different mathematical methods of measurement of error to determine if there were any differences in their ability to discriminate between a control group and subjects with a whiplash associated disorder. The four methods for measuring cervical joint position error were calculated using a previous data set consisting of 50 subjects with whiplash complaining of dizziness (WAD D), 50 subjects with whiplash not complaining of dizziness (WAD ND) and 50 control subjects. The results indicated that no one measure of HRA uniquely detected or defined the differences between the whiplash and control groups. Constant error (CE) was significantly different between the whiplash and control groups from extension (p<0.05). Absolute errors (AEs) and root mean square errors (RMSEs) demonstrated differences between the two WAD groups in rotation trials (p<0.05). No differences were seen with variable error (VE). The results suggest that a combination of AE (or RMSE) and CE are probably the most suitable measures for analysis of HRA.     

Head eye co-ordination and gaze stability in subjects with persistent whiplash associated disorders

Symptoms of dizziness, unsteadiness and visual disturbances are frequent complaints in persons with persistent whiplash associated disorders. This study investigated eye, head co-ordination and gaze stability in subjects with persistent whiplash (n?=?20) and asymptomatic controls (n?=?20). Wireless motion sensors and electro-oculography were used to measure: head rotation during unconstrained head movement, head rotation during gaze stability and sequential head and eye movements. Ten control subjects participated in a repeatability study (two occasions one week apart). Between-day repeatability was acceptable (ICC?>?0.6) for most measures. The whiplash group had significantly less maximal eye angle to the left, range of head movement during the gaze stability task and decreased velocity of head movement in head eye co-ordination and gaze stability tasks compared to the control group (p??0.55) between both unrestrained neck movement and neck pain and head movement and velocity in the whiplash group. Deficits in gaze stability and head eye co-ordination may be related to disturbed reflex activity associated with decreased head range of motion and/or neck pain. Further research is required to explore the mechanisms behind these deficits, the nature of changes over time and the tests' ability to measure change in response to rehabilitation.     

Quantitative evaluation of sway as an indicator of functional balance in post-traumatic brain injury

The test of sway, using different conditions of stance with measurements of the average radial deviation of the center of pressure and its path length of sway per unit of time, has been shown to be a useful clinical tool in determining balance problems in traumatic brain injury (TBI) patients. Normative values were established to determine if an individual patient's sway values fell within the normal range (mean +/- 2SD). The tests have shown good test-retest reliability for TBI patients. In addition, it has been shown that the sensitivity of the test is sufficient to identify changes in patients' performances as their clinical conditions change. It has been demonstrated that the different stance conditions of the battery of tests become progressively more difficult to perform (from comfortable stance, eyes open and eyes closed, through narrow stance, eyes open and eyes closed, to tandem stance with right or left foot forward, eyes open and eyes closed). By using these subtests, it is easy to distinguish between the performances of able-bodied patients and TBI patients with very mild balance problems. The validity of the measure has been documented by correlating the sway performance with clinical functional performance tests. The test performance also correlates with the patient's own assessment of his or her gait difficulties. The limited data available suggest that the test of sway relates difficulties in static balance to the frequency of falls. Finally, subtests permit identification of specific problems in maintaining balance as a basis for therapeutic intervention.(ABSTRACT TRUNCATED AT 250 WORDS)     

The influence of neck pain on balance and gait parameters in community-dwelling elders

Neck pain has been shown to be associated with balance disturbances. Balance and gait speed are also known to decline with ageing. The aim of this study was to determine whether the presence of neck pain was associated with a decline in postural stability and gait speed over and above what is expected with normal ageing. Twenty female subjects with idiopathic neck pain and 20 healthy female controls aged between 65 and 82 years were studied. Subjects performed balance tests on a computerised force plate under conditions of eyes open, eyes closed on firm and soft surfaces in comfortable and narrow stance. Sway energy and root mean square (RMS) amplitude of sway were measured. Subjects also undertook a Timed Ten Metre Walk Test, with and without head turning.There were trends for the elderly group with neck pain to have poorer balance than the healthy controls across most balance conditions, although differences were significant only in the following tests; comfortable stance—eyes closed on a firm surface (p=0.02), eyes open on a soft surface (p=0.01); narrow stance—eyes open on a firm surface (p=0.02). In the Timed Ten meter Walk Test, elderly subjects with neck pain had a slower self-selected gait speed (p=0.02) and cadence (p=0.04) in the head turn condition, as well as a longer gait cycle duration both with (p=0.00) and without head turns (p=0.04). The results of this study suggest that neck pain in the elderly may contribute to some disturbance in balance and gait parameters over and above that which occurs with normal ageing.     

Mediolateral sway in single-leg stance is the best discriminator of balance performance for Tai-Chi practitioners

OBJECTIVES: To identify a balance measure that can best distinguish Tai-Chi from non-Tai-Chi practitioners and to examine whether longer Tai-Chi practice results in better balance control. DESIGN: Cross-sectional comparative study. SETTING: Community. PARTICIPANTS: Nineteen Tai-Chi practitioners (who practiced Tai Chi for 30-45min at least 3/wk for >1y) and 19 healthy subjects with regular exercise habits (who practiced Tai Chi for 30-45min at least 3/wk for >1y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Scores on 2 clinical tests (functional reach, gait) and 1 laboratory test (postural sway). RESULTS: Tai-Chi practitioners had better clinical test scores for functional reach, gait speed, stride length, and sway parameters during single-leg stance (P<.05). Sway in mediolateral direction during single-leg stance was the balance performance variable that best discriminated the Tai-Chi group from non-Tai-Chi group. More experience practicing Tai Chi was associated with better balance performance. CONCLUSIONS: Tai-Chi practitioners performed better both in clinical and laboratory tests when compared with subjects who did not practice Tai Chi. More Tai-Chi experience was associated with better postural control.     

The relationship of cervical joint position error to balance and eye movement disturbances in persistent whiplash

Cervical joint position error (JPE) has been used as a measure of cervical afferent input to detect disturbances in sensori-motor control as a possible contributor to a neck pain syndrome. This study aimed to investigate the relationship between cervical JPE, balance and eye movement control. It was of particular interest whether assessment of cervical JPE alone was sufficient to signal the presence of disturbances in the two other tests. One hundred subjects with persistent whiplash-associated disorders (WADs) and 40 healthy controls subjects were assessed on measures of cervical JPE, standing balance and the smooth pursuit neck torsion test (SPNT). The results indicated that over all subjects, significant but weak-to-moderate correlations existed between all comfortable stance balance tests and both the SPNT and rotation cervical JPE tests. A weak correlation was found between the SPNT and right rotation cervical JPE. An abnormal rotation cervical JPE score had a high positive prediction value (88%) but low sensitivity (60%) and specificity (54%) to determine abnormality in balance and or SPNT test. The results suggest that in patients with persistent WAD, it is not sufficient to measure JPE alone. All three measures are required to identify disturbances in the postural control system.     

高龄老人前庭功能、平衡功能、视动功能的定量评价

背景80岁以上老年人眩晕及跌倒发生率高,且与位、听、视功能减退有关.目的定量评价80岁以上老年人的位、听、视功能.设计以老年患者为观察对象,定量评价其位功能(前庭平衡功能)、听功能(语频听阈)、视功能(视动功能).单位解放军总医院耳鼻咽喉科.对象选择1993-03/1994-01解放军总医院康复部因全身系统疾病住院的老年男性41人,年龄80～94岁.有耳鸣症状者12人,有眩晕症状者20人.选择同期本院健康体检60～79岁健康老干部作为对照,男11例,女7例.该组患者均无耳鸣、耳聋等耳部症状及眩晕症状.所有老年人均自愿参加.方法对患者进行耳鼻喉全面检查.听功能检查包括纯音测听及脑干电反应测听.前庭功能(位功能)用旋转检测试前庭眼反射,1°/s角加速到90°/s后恒速旋转至眼震消失后骤停记录旋转后眼震,先向左转间隔10 min后向右转,计算慢相角速度并计算左右不对称比值;前庭脊髓反射(位功能,VSR)用平衡台测试,并计算人体重心晃动的轨迹长度和速度.视动中枢检查(视功能)用光标测试,包括扫视、跟踪、视动3项眼动功能.主要观察指标语频听阈、前庭眼反射试验、前庭脊髓反射试验及视动功能检查＞80岁老年人位、听、视功能结果,并与60～79岁老年人平衡功能、视动功能检查结果进行对比.结果按实际处理分析,进行语频听阈、前庭眼反射、前庭脊髓反射、平衡功能和视动功能检查的80岁以上老年人分别为41,24,39,40和34人,进行平衡功能和视动功能检查的60～79岁老年人分别为18和10人,脱落者为不愿接受该项检查者.①听功能80岁以上老年人41人中语频听阈正常者13耳(16%),听力下降者69耳(64%).②位功能前庭眼反射正常者15人(62%),异常者9人(38%),前庭脊髓反射正常10人(26%),异常29人(74%).③平衡功能人体平衡功能各参数中以重心晃动的轨迹长度与速度最有价值,两个年龄段老年人的闭眼人体重心轨迹长度和晃动速度明显长于和大于睁眼(P＜0.01).＞80岁老年人人体重心轨迹长度和晃动速度明显长于和大于60～79岁老年人(P＜0.01).④视动功能＞80岁老年人与60～79岁老年人视动增益相似(P＞0.05),扫视潜伏期和跟踪失真度明显长于和大于60～79岁老年人(P＜0.05～0.01).结论80岁以上老年人大部分存在听力和位功能下降现象;视动和平衡功能较60～79岁老人更加退化.     

Balance (perceived and actual) and preferred stance width during pregnancy

BACKGROUND: Pregnant women often remark that their balance degrades during pregnancy; however, it appears that no studies have documented the gravida's perception of her balance nor measured direction-specific changes in balance throughout pregnancy or after delivery. METHODS: Thirty women, fifteen pregnant and fifteen non-pregnant controls, were tested monthly and through 6-month postpartum. For each session, perceived degradation in sense of balance, laboratory-based balance measures, stance width, and the number of falls since the previous session were recorded. Laboratory-based balance measures, quantified by direction-specific measures of postural sway, were computed from ten 30s quiet-standing trials on a stationary force platform. Repeated-measures analysis of variance, paired t-tests, and Pearson correlations were use to examine group and time effects. FINDINGS: For the pregnant group, perceived balance degradation and stance width were highly correlated (r = 0.94). Both increased during pregnancy (P < or = 0.016) and dropped to near-control levels after delivery (P < or = 0.004). Compared to the control group, pregnant subjects displayed increased sway, especially in the anterior-posterior and radial directions (P < or = 0.039). Anterior-posterior sway measures strongly correlated with perceived balance (0.82 > r > 0.72) and also decreased significantly between the third trimester and postpartum (P < or = 0.029). Interestingly, medial-lateral balance measures varied little during pregnancy, but increased after delivery. Contrary to recent work suggesting fall rates of 25%, only 13% of our subjects (n = 2) fell during pregnancy. INTERPRETATION: Perceived degradation in balance during pregnancy was strongly related to increasing postural sway instability in the anterior-posterior direction. Lateral stability was maintained during pregnancy and likely accomplished by increasing stance width.     

健康青年人双足间的距离对静态站立平衡功能的影响

目的 探讨健康青年人静态站立时双足间的距离对平衡功能的影响，为平衡功能训练提供理论基础。 方法 选取健康青年受试者30例，其中男7例，女23例，分别在睁眼和闭眼两种方式下，采用平衡评估训练仪评估双足并拢站立、双足分开（50cm）站立和双足最适距离站立3种模式下的静态平衡功能，即压力中心（COP）的相关参数，包括前后摆动幅度标准差、左右摆动幅度标准差、前后平均运动速度、左右平均运动速度、运动椭圆面积、运动长度共6个量化指标，并进行数据分析。 结果 双足最适距离站立时，双侧足跟间平均距离为（18.63±3.67）cm，双侧足尖间平均距离为（29.60±4.93）cm。在睁眼和闭眼状态下，双足并拢站立时的前后摆动幅度标准差、左右摆动幅度标准差、前后平均运动速度、左右平均运动速度、运动椭圆面积和运动长度与双足分开（50cm）站立和最适距离站立时比较，差异均有统计学意义（P<0.05）；睁眼和闭眼状态下，双足最适距离站立时的左右摆动幅度标准差、左右平均运动速度、运动椭圆面积、运动长度与双足分开（50cm）站立时比较，差异均有统计学意义（P<0.05）。 结论 健康青年人在静态站立时，双下肢间有最适距离，在这种距离下，站立静态平衡功能最佳。     

Clinical tests of standing balance: performance of persons with multiple sclerosis

OBJECTIVE: To investigate differences in performance between people with multiple sclerosis (MS) and control subjects on clinical tests of balance, and to assess performance consistency on balance tests in people with MS from morning to afternoon. STUDY DESIGN: Two factor repeated measures design with a two group sample of convenience. SETTING: Kingston Centre and the Camberwell Centre of the MS Society of Victoria, Australia. SUBJECTS: Fourteen people with MS and 14 control subjects matched for age, height, and sex. MAIN OUTCOME MEASURES: Subjects were measured on their ability to maintain standing balance in steady stance, (feet apart, feet together, stride stance, tandem stance, and single leg stance), during self-generated perturbations (functional reach, arm raise, and step tests) and in response to an external perturbation. Participants with MS were also asked to rate their fatigue level in the morning and afternoon. RESULTS: There were no differences between MS and control groups on the ability to maintain standing balance with feet apart, feet together, or in stride stance. Participants with MS performed more poorly than control subjects in tandem stance and single leg stance and in the functional reach test, arm raise test, step test, and in response to an external perturbation. There was little change in balance from morning to afternoon in participants with MS (ICCs (2,1) .70 to .94), despite an increase in self-rated fatigue (t(14) = -3.14, p = .008). CONCLUSION: The ability to maintain balance in standing is a marked problem in people with MS despite the consistency of their performance from morning to afternoon.     

The effect of walking aids on balance and weight-bearing patterns of patients with hemiparesis in various stance positions

BACKGROUND AND PURPOSE: Standard and quad canes are often prescribed to patients with hemiparesis, yet their effect on postural control remains unclear. Thus, the objective of this study was to examine the effects of standard and quad canes on postural sway and on weight-bearing patterns in patients with hemiparesis. SUBJECTS: Thirty subjects with a diagnosis of unilateral hemiparesis following a stroke (patient group; mean age=71.2 years, SD=7.0) and 20 age-matched, community-dwelling volunteers without hemiparesis (comparison group; mean age=72.1 years, SD=5.2) participated in the study. METHODS: Postural sway and percentage of body weight (%BW) borne by each extremity were measured in 3 positions: with the heels aligned with each other (aligned position) and in staggered foot positions with either the affected or unaffected extremity placed forward (affected FW and unaffected FW positions). All subjects were tested in each position with no cane, a standard cane, and a quad cane. The order of tests was randomized, and analysis of data included use of an analysis of variance and adjusted Tukey-Kramer tests. RESULTS: In both the aligned and unaffected FW positions, postural sway was reduced only with the quad cane. Both types of canes reduced postural sway in the affected FW position; however, the quad cane had a greater effect. An asymmetrical weight distribution between the lower extremities did not change in the patient group across positions, even with walking aids. DISCUSSION AND CONCLUSION: A quad cane appears to be more effective than a standard cane in decreasing postural sway in patients with moderate impairment secondary to hemiparesis during stance. The greatest effect on postural sway occurred when the assistive device was contralateral to the foot placed forward. The use of a cane does not appear to adversely affect the asymmetrical weight-bearing pattern during stance that is characteristic of patients with hemiparesis, even when balance is challenged by decreasing the base of support.     

Development of motor system dysfunction following whiplash injury

Dysfunction in the motor system is a feature of persistent whiplash associated disorders. Little is known about motor dysfunction in the early stages following injury and of its progress in those persons who recover and those who develop persistent symptoms. This study measured prospectively, motor system function (cervical range of movement (ROM), joint position error (JPE) and activity of the superficial neck flexors (EMG) during a test of cranio-cervical flexion) as well as a measure of fear of re-injury (TAMPA) in 66 whiplash subjects within 1 month of injury and then 2 and 3 months post injury. Subjects were classified at 3 months post injury using scores on the neck disability index: recovered (<8), mild pain and disability (10-28) or moderate/severe pain and disability (>30). Motor system function was also measured in 20 control subjects. All whiplash groups demonstrated decreased ROM and increased EMG (compared to controls) at 1 month post injury. This deficit persisted in the group with moderate/severe symptoms but returned to within normal limits in those who had recovered or reported persistent mild pain at 3 months. Increased EMG persisted for 3 months in all whiplash groups. Only the moderate/severe group showed greater JPE, within 1 month of injury, which remained unchanged at 3 months. TAMPA scores of the moderate/severe group were higher than those of the other two groups. The differences in TAMPA did not impact on ROM, EMG or JPE. This study identifies, for the first time, deficits in the motor system, as early as 1 month post whiplash injury, that persisted not only in those reporting moderate/severe symptoms at 3 months but also in subjects who recovered and those with persistent mild symptoms.     

Audio-biofeedback improves balance in patients with bilateral vestibular loss

OBJECTIVE: To evaluate the effectiveness of an audio-biofeedback (ABF) system for improving balance in patients with bilateral vestibular loss (BVL). DESIGN: Before-after trial. SETTING: University balance disorders laboratory. PARTICIPANTS: Nine subjects with BVL and 9 unaffected subjects as controls. INTERVENTION: Trunk acceleration ABF while standing on foam with eyes closed. MAIN OUTCOME MEASURE: Balance stability was evaluated according to the following parameters: the root mean square of (1) the center of pressure (COP) displacements and of (2) the trunk accelerations; the COP bandwidth; the time spent by the participant within +/-1 degrees threshold from their baseline COP position; and the mean accelerations of the trunk while the participant was swaying outside this +/-1 degrees threshold. RESULTS: Participants with BVL had significantly larger postural sway than did unaffected participants. Those with BVL, while using ABF, decreased sway area by 23%+/-4.9%, decreased trunk accelerations by 46%+/-9.9%, and increased time spent within +/-1 degrees sway threshold by 195%+/-34.6%. CONCLUSIONS: ABF improved stance stability of participants with BVL by increasing the amount of postural corrections.     

The effect of physical therapy on balance of patients with Parkinson's disease

Physical therapy can improve performance of balance tests in patients with Parkinson's disease. Parkinson's disease is a chronic progressive neurological disturbance with significant effect on movements, cognitive functions, autonomous systems and psychosocial activities. The effects of physical therapy are rarely reported and not sufficiently studied. This prospective study comprised 40 persons with stage III Parkinson's disease, according to aged over 50 years and 20 healthy controls of the same age. Patients were medically stable and had no other neurological deficits, postural hypotensia, visual disturbances or musculo-skeletal deficits. Balance tests before and after physical therapy were analysed according to. Balance tests in patients with Parkinson's disease resulted in significant differences of values for tandem stance, one leg stance, step test and external perturbation when compared to the controls, and between groups with and without falling tendency. Tandem stance, one leg stance, step test and external perturbation can be used for differentiation between groups with and without a tendency to fall. Physical therapy resulted in significant improvement of these tests in both the groups analysed. Systematic application of physical therapy, as part of team treatment, improves the balance of patients with Parkinson's disease.