Horemans, H.L.D.

Excellent test-retest and inter-rater reliability for Tardieu Scale measurements with inertial sensors in elbow flexors of stroke patients (Article)

2011-02-01T00:00:00Z

Background: Spasticity is often clinically assessed with the Tardieu Scale, using goniometry to measure the range of motion and angle of catch. However, the test-retest and inter-rater reliability of these measurements have been questioned. Inertial sensors (IS) have been developed to measure orientation in space and are suggested to be a more appropriate tool than goniometry to measure angles in Tardieu Scale measurements. Objective: To compare the test-retest and inter-rater reliability of Tardieu Scale scores measured with IS and goniometry. Methods: Two physiotherapists performed Tardieu Scale measurements in two sessions, using both goniometry and IS, to quantify spasticity in elbow flexors of 13 stroke patients. Results: For goniometry, test-retest and inter-rater reliability proved to be excellent (ICC 0.86) and fair to good (ICC 0.66), respectively. For IS, both test-retest (ICC 0.76) and inter-rater reliability (ICC 0.84) were excellent. Conclusions: Inertial sensors are reliable and accurate to use in Tardieu Scale measurements to quantify spasticity in the elbow flexors of hemiplegic stroke patients.

The effects of high custom made shoes on gait characteristics and patient satisfaction in hemiplegic gait (Article)

2011-01-01T00:00:00Z

To determine the effects of a temporary high custom made orthopaedic shoe on functional mobility, walking speed, and gait characteristics in hemiplegic stroke patients. In addition, interference of attentional demands and patient satisfaction were studied.

Platform accelerations of three different whole-body vibration devices and the transmission of vertical vibrations to the lower limbs (Article)

2009-10-01T00:00:00Z

Physical whole-body vibration (WBV) exercises become available at various levels of intensity. In a first series of measurements, we investigated 3-dimensional platform accelerations of three different WBV devices without and with three volunteers of different weight (62, 81 and 100 kg) in squat position (150° knee flexion). The devices tested were two professional devices, the PowerPlate and the Galileo-Fitness, and one home-use device, the PowerMaxx. In a second series of measurements, the transmission of vertical platform accelerations of each device to the lower limbs was tested in eight healthy volunteers in squat position (100° knee flexion). The first series showed that the platforms of two professional devices vibrated in an almost perfect vertical sine wave at frequencies between 25-50 and 5-40 Hz, respectively. The platform accelerations were slightly influenced by body weight. The PowerMaxx platform mainly vibrated in the horizontal plane at frequencies between 22 and 32 Hz, with minimal accelerations in the vertical direction. The weight of the volunteers reduced the platform accelerations in the horizontal plane but amplified those in the vertical direction about eight times. The vertical accelerations were highest in the Galileo (∼15 units of g) and the PowerPlate (∼8 units of g) and lowest in the PowerMaxx (∼2 units of g). The second series showed that the transmission of vertical accelerations at a common preset vibration frequency of 25 Hz were largest in the ankle and that transmission of acceleration reduced ∼10 times at the knee and hip. We conclude that large variation in 3-dimensional accelerations exist in commercially available devices. The results suggest that these differences in mechanical behaviour induce variations in transmissibility of vertical vibrations to the (lower) body.

Sensitivity of accelerometry to assess balance control during sit-to-stand movement (Article)

2008-10-01T00:00:00Z

Accelerometry has the potential to measure balance, defined as high-frequency body sway, ambulatorily in a simple and inexpensive way. The aim of this study was to determine and compare the sensitivity of accelerometric balance parameters during the sit-to-stand (STS) movement. Eleven healthy subjects (four males, 28.2 ± 7.9 years) and 31 patients with stroke (21 males; 63.3 ± 12.8 years) were included. The healthy subjects performed STS movements in four conditions with different levels of difficulty. Data of the patients were compared 1) with healthy subjects, 2) between patient subgroups, and 3) between different phases of recovery to assess the sensitivity of accelerometry for differences in balance control. Accelerometers were attached to the trunk, and force plate measurements were simultaneously done in the healthy subjects. Main outcome measures were root mean square (rms) and area under the curve (AUC) derived from the high-frequency component of the transversal acceleration signal of the trunk. In all comparisons there was a significant difference in AUC data (p < 0.05), and AUC appeared to be more sensitive than rms. Variability in AUC was not completely or mainly the result of changes and differences in the duration of the STS movement. As a conclusion, accelerometry is a potentially valuable technique to measure balance during the STS movement.

Validity of accelerometry in assessing the duration of the sit-to-stand movement (Article)

2008-07-16T00:00:00Z

Accelerometry is frequently used in movement analysis to assess body postures and motions. Here, we assessed the validity of ambulatory accelerometric measurement of the sit-to-stand (STS) movement duration. We compared accelerometric and opto-electronic assessment of the STS movement duration under four conditions (comfortable, slow, fast movement and exaggerated trunk flexion) with six healthy subjects and six subjects with stroke who performed movements six times under each condition. Accelerometric and opto-electronic data of STS movement duration were strongly related (r = 0.98). Accelerometry showed a fixed bias of 0.07 s (95% CI 0.008, 0.141) in healthy subjects and 0.32 s (95% CI 0.223, 0.422) in stroke subjects. In healthy subjects, a significant negative proportional bias of 0.1 was detected (95% CI -0.160, -0.032). Accelerometry showed discriminative validity in comparing stroke subjects to healthy subjects, and in comparing speed conditions. Our results indicate that accelerometry can provide valid data on the STS movement duration, furthermore during its use additional information on the STS movement, such as balance control, can be recorded.

Validity of the Pedar Mobile system for vertical force measurement during a seven-hour period (Article)

2006-12-01T00:00:00Z

Objective measurement of weight bearing during a long-term period can give insight into the postoperative loading of the lower extremity of orthopedic patients to avoid complications. This study investigated the validity of vertical ground reaction force measurements during a long-term period using the Pedar Mobile insole pressure system, by comparing it with a Kistler force platform. In addition, the validity of a new sensor drift correction algorithm to correct for offset drift in the Pedar signal was evaluated. Ground reaction force data were collected during dynamic and static conditions from five healthy subjects every hour for 7 h. A mean offset drift of 14.6% was found after 7 h. After applying the drift correction algorithm the Pedar system showed a high accuracy for the second peak in the ground reaction force-time curve (1.1 to 3.4% difference, p>0.05) and step duration (-2.0 to 4.4% difference, p>0.05). Less accuracy was found for the first peak in the ground reaction force-time curve (5.2 to 12.0% difference; p<0.05 for the first 3 h, p>0.05 for the last 4 h) and, consequently, in the vertical force impulse (5.5 to 11.0% difference, p>0.05). The Pedar Mobile system appeared to be a valid instrument to measure the vertical force during a long-term period when using the drift correction program described in this study.