Characterizing the profiles of patients with acute concussion versus prolonged post-concussion symptoms in Ontario.

Identifying vulnerability factors for developing persisting concussion symptoms is imperative for determining which patients may require specialized treatment. Using cross-sectional questionnaire data from an Ontario-wide observational concussion study, we compared patients with acute concussion (≤ 14 days) and prolonged post-concussion symptoms (PPCS) (≥ 90 days) on four factors of interest: sex, history of mental health disorders, history of headaches/migraines, and past concussions. Differences in profile between the two groups were also explored. 110 patients with acute concussion and 96 patients with PPCS were included in our study. The groups did not differ on the four factors of interest. Interestingly, both groups had greater proportions of females (acute concussion: 61.1% F; PPCS: 66.3% F). Patient profiles, however, differed wherein patients with PPCS were significantly older, more symptomatic, more likely to have been injured in a transportation-related incident, and more likely to live outside a Metropolitan city. These novel risk factors for persisting concussion symptoms require replication and highlight the need to re-evaluate previously identified risk factors as more and more concussions occur in non-athletes and different risk factors may be at play.

Neck and Inspiratory Muscle Recruitment during Inspiratory Loading and Neck Flexion.

PURPOSE: This study aimed to compare muscle activation of the diaphragm (DIA), scalenes (SA), parasternal intercostals (PS), and sternomastoid (SM) during submaximal intermittent neck flexion (INF) versus submaximal inspiratory threshold loading (ITL) until task failure in healthy adults. METHODS: Twelve healthy adults performed submaximal ITL or INF tests in random order for 2 d. Surface electromyography was monitored to acquire root mean square (RMS) and median power frequency (MPF) from the SA, PS, SM, and DIA. Maximal inspiratory pressures and maximal voluntary contraction for neck flexion were determined. Next, participants performed the first submaximal test-ITL or INF-targeting 50% ± 5% of the maximal inspiratory pressure or maximal voluntary contraction, respectively, until task failure. After a rest, they performed the other test until task failure. Two days later, they performed ITL and INF but in the opposite order. The Borg scale assessed breathlessness and perceived exertion. RESULTS: Endurance times for ITL and INF were 38.1 and 26.3 min, respectively. INF activated three of four inspiratory muscles at higher average RMS (PS, SM, and SA) and at different MPF (PS, SM, and DIA but not SA) compared with ITL. During ITL, RMS did not change in the four inspiratory muscles over time, but MPF decreased in PS, SM, and SA (P < 0.04). In contrast, RMS increased in three of four inspiratory muscles (SM, PS, and SA) during INF, but MPF did not change throughout its duration. Borg rating was 3.9-fold greater than ITL compared with INF. CONCLUSION: At a similar percentage of maximal load, INF evokes greater activation of primary muscles of inspiration (PS and SA) and a major accessory muscle of inspiration (SM) compared with ITL during a prolonged submaximal protocol.

Development of a video-based technique for ambulatory monitoring of foot placement with an instrumented rollator.

OBJECTIVE: To develop a video-based system, mounted on a rollator to quantify the step width values of rollator users in the community. SUBJECTS: A total of 5 able-bodied young adults, age range 24-28 years. METHODS: A digital video camera system was mounted on the rollator frame to capture the position of the participant's feet during overground walking. A method of estimating step width from the video data was developed and evaluated against the output from a concurrently recording Vicon MX motion capture system. RESULTS: Mean step widths of the rollator and motion capture systems were 14.40 cm (standard deviation (SD) 4.64) and 14.37 cm (SD 4.34), respectively, revealing a strong level of agreement; intra-class correlation coefficient 0.999 (95% confidence interval (95% CI) 0.987-1.000; and root-mean-square difference 0.70 cm. CONCLUSION: The video-based system mounted on a rollator to collect foot placement data enabled accurate measurement of step width during rollator use. The ability to record foot placement measurements outside the laboratory setting, characterizing foot placement patterns occurring in the community, will enable research into how these assistive devices influence mobility during everyday use.

Combining ambulatory and laboratory assessment of rollator use for balance and mobility in neurologic rehabilitation in-patients.

PURPOSE: Despite the common use of rollators (four-wheeled walkers), understanding their effects on gait and balance is limited to laboratory testing rather than everyday use. This study evaluated the utility of an ambulatory assessment approach to examine balance and mobility in everyday conditions compared to a laboratory assessment. METHODS: Standing and walking with a rollator was assessed in three neurological rehabilitation in-patients under two conditions: (1) in laboratory (i.e. forceplate, GaitRite), and (2) while performing a natural walking course within and outside of the institution. An instrumented rollator (iWalker) was used to measure variables related to the balance control (e.g. upper limb kinetics), destabilizing events (e.g. stumbling), and environmental context. RESULTS: Two of three patients demonstrated greater reliance on the rollator for standing balance (2.3-5.9 times higher vertical loading, 72-206% increase in COP excursion) and 29-42% faster gait during the walking course compared to the laboratory. Importantly, destabilizing events (collisions, stumbling) were recorded during the walking course. Such events were not observed in the laboratory. CONCLUSION: This study illustrated a greater reliance on the rollator during challenges in everyday use compared to laboratory assessment and provided evidence of specific circumstances associated with destabilizing events that may precipitate falls in non-laboratory settings. Implications for Rehabilitation The value of combining laboratory and ambulatory assessment approaches to provide a more comprehensive profile of the risks and benefits of rollator use to prevent falling was studied. Patients demonstrated greater reliance on rollator assistive devices for standing balance and exhibited higher gait speeds during ambulatory assessment, compared to standard laboratory protocols. Repeated instances of events that may precipitate falls (e.g. collisions, stumbling, and unloading behaviors) were observed only during the ambulatory assessment. Individual challenges to balance can be used to identify specific training targets, assess suitability for assistive devices, and recommend rehabilitation goals.

Foot placement patterns of female rollator users with multiple sclerosis in the community.

PURPOSE: The objective of this study was to investigate the relationship between medio-lateral foot placement characteristics and environmental context when individuals with Multiple Sclerosis (MS) walk with a rollator (four-wheeled walker). METHOD: Ten women diagnosed with MS, who used rollators regularly, participated in this study. First, a rollator-based technique of calculating step width (SW) was validated in this patient population by comparing the output of an instrumented rollator (iWalker) to a laboratory-based Vicon Motion Capture System. Secondly, the iWalker-based technique was used to calculate the participants' SW and SW variability as they used the iWalker in four common outdoor community environments. RESULTS: There was a strong level of agreement between the iWalker and Vicon SW calculations, with an intra-class correlation coefficient of 0.993 and a root-mean-square difference of 0.71 cm. Furthermore, SW variability (P = 0.002), but not SW (P = 0.288), was influenced by the walking environment (i.e. between the in-lab vs. up-ramp and up-ramp vs. down-ramp conditions). CONCLUSIONS: Foot placement variability appears to be influenced by the walking environment of MS patients. Therefore, an enhanced understanding of walker-user interactions in relation to the environment must be established in order to improve mobility.

Preliminary evaluation of a commercially available videogame system as an adjunct therapeutic intervention for improving balance among children and adolescents with lower limb amputations.

OBJECTIVES: To examine the safety, feasibility, and balance performance effects of a 4-week home-based balance therapy program using a commercially available videogame system. DESIGN: A pilot study involving a preintervention and postintervention design was conducted with measurements taken at baseline, immediately postintervention (week 5), and at follow-up (week 13) for retention. SETTING: University hospital outpatient clinic and participants' places of residence. PARTICIPANTS: Children and adolescents with unilateral lower limb amputation (n=6; 3 transfemoral [TF] and 3 Van Ness) and age-matched, typically developing individuals (n=10) for baseline comparison. INTERVENTION: Two videogames involving weight shifting in standing were each played at home for 20 min/d, 4d/wk for a period of 4 weeks. A physical therapist provided initial instruction and monitoring. MAIN OUTCOME MEASURES: Postural control characteristics using center of pressure (COP) displacements during quiet standing; functional balance using the Community Balance and Mobility Scale (CB&M); and compliance, safety, and feasibility using custom questionnaires. RESULTS: Average playing times for the first 3 weeks ranged from 16.0 to 21.1 minutes for the 2 games. At baseline, the children and adolescents with TF amputation had substantially greater COP displacements than the Van Ness group and typically developing children and adolescents. Immediately postintervention, the COP displacements decreased in the TF amputees, resulting in values that were closer to those of the typically developing children. The average increase in CB&M score from baseline to follow-up was 6 points across participants. CONCLUSIONS: In-home, videogame-based balance training therapies can achieve excellent compliance in children and adolescents with lower limb amputation. With proper instructions and monitoring, the therapeutic intervention can be safely administered. Some improvements in postural control characteristics were seen in children and adolescents with balance deficits immediately postintervention, but long-term retention remains unclear.

Frontal plane standing balance with an ambulation aid: Upper limb biomechanics.

Despite widespread acceptance of clinical benefits, empirical evidence to evaluate the advantages and limitations of ambulation aids for balance control is limited. The current study investigates the upper limb biomechanical contributions to the control of frontal plane stability while using a 4-wheeled walker in quiet standing. We hypothesized that: (1) upper limb stabilizing moments would be significant, and (2) would increase under conditions of increased stability demand. Factors influencing upper limb moment generation were also examined. Specifically, the contributions of upper limb center-of-pressure (COP(hands)), vertical and horizontal loads applied to the assistive device were assessed. The results support a significant mechanical role for the upper limbs, generating 27.1% and 58.8% of overall stabilizing moments under baseline and challenged stability demand conditions, respectively. The increased moment was achieved primarily through the preferential use of phasic upper limb control, reflected by increased COP(hands) (baseline vs. challenged conditions: 0.29 vs. 0.72cm). Vertical, but not horizontal, was the primary force direction contributing to stabilizing moments in quiet standing. The key finding that the upper limbs play an important role in effecting frontal plane balance control has important implications for ambulation aid users (e.g., elderly, stroke, and traumatic brain injury).

Estimation of the centre of mass for the study of postural control in Idiopathic Scoliosis patients: a comparison of two techniques.

The objective of the present study is to quantify the position of the Centre of Mass (COM) during quiet standing using a force plate and compare this technique to the quantification of the COM with an anthropometric model. The postural control of 18 healthy adolescents and 22 IS patients was evaluated using an Optotrak 3D kinematic system, and two AMTI force plates during quiet standing. The position of anatomical landmarks tracked by the Optotrak system served to estimate the position of the COM of both groups using an anthropometric model (COM(anth)). The force plate served to estimate the position of the COM through double integration of the horizontal ground reaction forces (COM(gl)). The mean position and root mean square (RMS) amplitude of COM(gl, )in reference to the base of support (BOS) and the first sacral prominence (S1) were quantified in the Anterior-Posterior (A/P) and Medial-Lateral (M/L) directions. There was a significant difference between the control subjects and IS patients for the displacement of the COM(gl) in reference to the BOS in both the A/P and M/L directions. There was no difference between groups for the mean position of the COM(gl), however, 63% of the IS and 43% of the controls had a lateral position of the COM(gl )in reference to S1 of greater than 5 mm. There was a significant difference between groups in the A/P and M/L directions for the amplitude of error between the COM(gl) and COM(anth) techniques.

Ambulatory monitoring of activity levels of individuals in the sub-acute stage following stroke: a case series.

BACKGROUND: There is an important need to better understand the activities of individual patients with stroke outside of structured therapy since this activity is likely to have a profound influence on recovery. A case-study approach was used to examine the activity levels and associated physiological load of patients with stroke throughout a day. METHODS: Activities and physiologic measures were recorded during a continuous 8 hour period from 4 individuals in the sub-acute stage following stroke (ranging from 49 to 80 years old; 4 to 8 weeks post-stroke) in an in-patient rehabilitation hospital. RESULTS: Both heart rate (p = 0.0207) and ventilation rate (p < 0.0001) increased as intensity of activity increased. Results revealed individual differences in physiological response to daily activities, and large ranges in physiological response measures during 'moderately' and 'highly' therapeutic activities. CONCLUSION: Activity levels of individuals with stroke during the day were generally low, though task-related changes in physiologic measures were observed. Large variability in the physiological response to even the activities deemed to be greatest intensity suggests that inclusion of such extended measurement of physiologic measures may improve understanding of physiological profile that could guide elements of the physical therapy prescription.

Parallels in control of voluntary and perturbation-evoked reach-to-grasp movements: EMG and kinematics.

To determine the potential differences in control underlying compensatory and voluntary reach-to-grasp movements the current study compared the kinematic and electromyographic profiles associated with upper limb movement. Postural perturbations were delivered to evoke compensatory reach-to-grasp in ten healthy young adult volunteers while seated on a chair that tilted as an inverted pendulum in the frontal plane. Participants reached to grasp a laterally positioned stable handhold and pulled (or pushed) to return the chair to vertical. The distinguishing characteristic between the two behaviors was the onset latency and speed of movement. Consistent with compensatory balance reactions, the perturbation-evoked reach response was initiated very rapidly (137 vs. 239 ms for voluntary). As well the movement time was shorter, and peak velocity was greater for PERT movements. In spite of the profound differences in timing, the sequence of muscle activity onsets and the order of specific kinematic events were not different between maximum velocity voluntary (VOL) and perturbation-evoked (PERT) reach-to-grasp movements. Peak velocity and grasp aperture occurred prior to hand contact with the target for PERT and VOL movements, and wrist trajectory was influenced by the direction of perturbation relative to the target. To achieve such target specific control for responses initiated within 100 ms of the perturbation, and when characteristics of body movement were unpredictable, the perturbation-evoked movements would need to incorporate sensory cues associated with body movement relative to the target into the earliest aspects of the movement. This suggests reliance on an internal spatial map constructed prior to the onset of perturbation. Parallels in electromyographic and kinematic profiles between compensatory and voluntary reach-to-grasp movements, in spite of temporal differences, lead to the view they are controlled by common neural mechanisms.

Evaluation of segmental postural characteristics during quiet standing in control and Idiopathic Scoliosis patients.

BACKGROUND: The complex skeletal deformations that accompany Idioapthic Scoliosis pose a challenge to the clinician to non-invasively discriminate Idiopathic Scoliosis patients from children with no pathology. Therefore, the focus of this study is to non-invasively evaluate the position and amplitude of displacement of the pelvis, shoulders and thorax during quiet standing of Idiopathic Scoliosis patients and control subjects. METHODS: The quiet standing posture of 18 healthy adolescent females and 22 Idiopathic Scoliosis subjects was evaluated using an Optotrak 3020 position sensor over a period of 120 s, with 4 repeat trials. Outcome measures included the mean position, root mean square amplitude and range over the duration of 120 s trials for both linear and angular measures of the pelvis, thorax and shoulders. Appropriate sample times were chosen and evaluated for stability over the 120 s period, and between trial reliability was evaluated. FINDINGS: There was a significant difference between groups for the mean position of the shoulder blade rotation in reference to the base of support and to the pelvis. The Idiopathic Scoliosis patients had a significantly larger root mean square amplitude of anterior-posterior displacement of the T1 and S1 spinous processes in reference to the base of support. There was no difference between the sample durations to estimate the mean position of the body segments, however the root mean square increased significantly. INTERPRETATION: This study demonstrates that postural abnormalities are evident during quiet standing in Idiopathic Scoliosis patients.

Simultaneous, bilateral, and three-dimensional gait analysis of elderly people without impairments.

OBJECTIVE: The main objectives of this study were to determine if the right and left lower limbs in the gait of elderly people developed similar muscle moment and power patterns and to determine whether their associated mechanical energies were different during two consecutive gait cycles. DESIGN: A total of 18 able-bodied male subjects aged 71 +/- 6.8 yrs participated in this study. Data were collected using three Optotrak position sensors and two AMTI force platforms. RESULTS: The peak muscle powers were very similar in the sagittal plane and reflected gait symmetry, except for greater and significant differences produced by the hip extensors. Differences in the frontal and transverse planes were mainly attributed to the actions taken by the muscles, leading the lower limbs to compensate and to dynamically balance and propel the body forward during two consecutive gait cycles. In terms of mechanical energy, 13% greater positive work was done in the left limb and was associated with asymmetrical behavior of the lower limbs to propel the body forward. The total negative work was similar for both limbs, and substantial work was done in the frontal plane by the hip, indicating the role of muscle activity in this plane to control the pelvis and trunk against gravitational forces. CONCLUSIONS: In addition to the importance of a balance-control function in the gait of healthy, elderly subjects, muscle activity made an important contribution to propelling the body forward. Gait asymmetry in elderly subjects seems to be related to different degrees of energy generated by the lower limbs for the propulsion function, whereas both limbs contribute similarly to the balance-control function.

SpineCor--a non-rigid brace for the treatment of idiopathic scoliosis: post-treatment results.

The objective of this study was to assess the success of treatment during the follow-up of a group of 195 idiopathic scoliosis (IS) patients consecutively treated with the SpineCor system. A survival analysis was performed to estimate the cumulative probability of success during treatment, at follow-up and for the combined treatment and follow-up period. Success was defined as either a correction or stabilization of +/-5 degrees or more, and failure as a worsening of more than 5 degrees. The patient cohort was categorized before treatment into curves less than 30 degrees (group 1), and curves greater than 30 degrees (group 2). The survival analysis indicated a cumulative probability of success that increased during treatment with the patient wearing the brace (Year 1: 0.30, 0.39; Year 2: 0.62, 0.79; Year 3: 0.92, 0.89, for groups 1 and 2 respectively). During the post-treatment follow-up period, there was a stabilization (Year 1 post-treatment: 0.94, 0.89; Year 2 post-treatment: 0.85, 0.81), with an overall probability of success of 0.92 and 0.88 after 4 years of combined treatment and post-treatment follow-up. For the 29 patients who had a minimum follow-up of 2 years (initial Cobb angle: 30 degrees +/-9 degrees ), the trend during treatment was a decrease in spinal curvature at 3 months, with a mean difference of 10 degrees (SD 5 degrees ); at termination of treatment a mean difference of 7 degrees (SD 7 degrees ); and at the time of the 1- and 2-year follow-ups there was a difference of 4 degrees (SD 7 degrees ) and 5 degrees (SD 7 degrees ) respectively, with reference to the initial out of brace condition. At 2 years follow-up there was an overall correction of greater than 5 degrees for 55% of the patients, 38% had a stabilisation and 7% had worsened by more than 5 degrees. This initial cohort of patients demonstrated a general trend of initial decrease in spinal curvature in brace, followed by a correction and/or stabilisation at the end of treatment, which was maintained through 1, and 2 years' follow-up.