Ron Clijsen

Hydration measurements of the stratum corneum: comparison between the capacitance method (digital version of the Corneometer CM 825 ® ) and the impedance method (Skicon-200EX ® )

Measurement of stratum corneum (SC) hydration often involves the use of commercial instruments. The aim of this study was to compare and validate two recent instruments: the Corneometer 825® (digital probe) and the Skicon‐200 EX®.

Evaluation of Central and Peripheral Fatigue in the Quadriceps Using Fractal Dimension and Conduction Velocity in Young Females

Purpose Over the past decade, linear and non-linear surface electromyography descriptors for central and peripheral components of fatigue have been developed. In the current study, we tested fractal dimension (FD) and conduction velocity (CV) as myoelectric descriptors of central and peripheral fatigue, respectively. To this aim, we analyzed FD and CV slopes during sustained fatiguing contractions of the quadriceps femoris in healthy humans. Methods A total of 29 recreationally active women (mean age±standard deviation: 24±4 years) and two female elite athletes (one power athlete, age 24 and one endurance athlete, age 30 years) performed two knee extensions: (1) at 20% maximal voluntary contraction (MVC) for 30 s, and (2) at 60% MVC held until exhaustion. Surface EMG signals were detected from the vastus lateralis and vastus medialis using bidimensional arrays. Results Central and peripheral fatigue were described as decreases in FD and CV, respectively. A positive correlation between FD and CV (R=0.51, p<0.01) was found during the sustained 60% MVC, probably as a result of simultaneous motor unit synchronization and a decrease in muscle fiber CV during the fatiguing task. Conclusions Central and peripheral fatigue can be described as changes in FD and CV, at least in young, healthy women. The significant correlation between FD and CV observed at 60% MVC suggests that a mutual interaction between central and peripheral fatigue can arise during submaximal isometric contractions.

The effect of post-exercise cryotherapy on recovery characteristics: a systematic review and meta-analysis

The aim of this review and meta-analysis was to critically determine the possible effects of different cooling applications, compared to non-cooling, passive post-exercise strategies, on recovery characteristics after various, exhaustive exercise protocols up to 96 hours (hrs). A total of n = 36 articles were processed in this study. To establish the research question, the PICO-model, according to the PRISMA guidelines was used. The Cochrane’s risk of bias tool, which was used for the quality assessment, demonstrated a high risk of performance bias and detection bias. Meta-analyses of subjective characteristics, such as delayed-onset muscle soreness (DOMS) and ratings of perceived exertion (RPE) and objective characteristics like blood plasma markers and blood plasma cytokines, were performed. Pooled data from 27 articles revealed, that cooling and especially cold water immersions affected the symptoms of DOMS significantly, compared to the control conditions after 24 hrs recovery, with a standardized mean difference (Hedges’ g) of -0.75 with a 95% confidence interval (CI) of -1.20 to -0.30. This effect remained significant after 48 hrs (Hedges’ g: -0.73, 95% CI: -1.20 to -0.26) and 96 hrs (Hedges’ g: -0.71, 95% CI: -1.10 to -0.33). A significant difference in lowering the symptoms of RPE could only be observed after 24 hrs of recovery, favouring cooling compared to the control conditions (Hedges’ g: -0.95, 95% CI: -1.89 to -0.00). There was no evidence, that cooling affects any objective recovery variable in a significant way during a 96 hrs recovery period.

Effectiveness of Exercise Therapy in Treatment of Patients With Patellofemoral Pain Syndrome: Systematic Review and Meta-Analysis

Background and Purpose This systematic review and meta-analysis was accomplished to determine whether exercise therapy is an effective intervention to reduce pain and patient-reported measures of activity limitations and participation restrictions (PRMALP) in patients with patellofemoral pain. Data Sources and Study Selection Randomized controlled trials in English and German languages published in the MEDLINE, Physiotherapy Evidence Database (PEDro), International Clinical Trials Registry Platform, and Cochrane databases were searched. Eligibility was assessed in 2 stages. The methodological quality of the studies was rated using the PEDro scale. Data were pooled using random-effects meta-analysis, allowing for variability among studies. For clinical use, overall estimates were re-expressed in the original visual analog scale scores. Significance was set at 5%. Data Extraction and Data Synthesis Fifteen studies, with a total of 748 participants, were included and pooled for the meta-analysis. Six studies compared the effect of exercise therapy with a control group receiving neither exercise therapy nor another intervention. Four studies compared the effect of exercise therapy versus additive therapy, and 5 studies compared different exercise interventions. In both comparisons, exercise therapy resulted in strong pain reduction and improvement of PRMALP effects. Significant short-term effects (≤12 weeks) of exercise therapy were found for pain and PRMALP, whereas long-term effects (≥26 weeks) were observed for PRMALP only. Limitations and Conclusion The 15 studies included in this analysis were of variable quality. Large-scale, high-quality randomized controlled trials are needed to further the evaluation of the possible effects of different exercise therapy modalities on patellofemoral pain. This meta-analysis presents evidence that exercise therapy has a strong pain-reducing effect and decreases PRMALP in patients with patellofemoral pain. However, the question of which exercise modality yields the strongest reducing effect on pain and PRMALP remains unanswered.

Rehabilitative ultrasound imaging of the supraspinatus muscle: Intra- and interrater reliability of thickness and cross-sectional area.

OBJECTIVE To examine intra- and interrater reliability of thickness and cross-sectional area (CSA) measurements of the supraspinatus muscle using rehabilitative ultrasound imaging (RUSI). METHODS Two physical therapists acquired b-mode images of the supraspinatus muscles in twenty-five healthy subjects. Thickness and CSA were measured. Intra- and interrater reliability were examined. RESULTS Intrarater reliability for thickness was high, (ICC1.1 0.91) for rater 1 and (ICC1.1 0.92) for rater 2. Intrarater reliability for CSA was also high, (ICC1.1 0.90) for rater 1 and (ICC1.1 0.85) for rater 2. Interrater reliability for the thickness was high, (ICC3.1 0.86). For CSA, interrater reliability was moderate, (ICC3.1 0.70). CONCLUSION Supraspinatus muscle thickness and CSA can be reliably measured by physical therapists in healthy subjects. These findings confirm that RUSI has an interesting potential for physiotherapy clinical practice, especially to assess morphometric changes in skeletal muscles. Further research is needed in subjects with shoulder disorders.

Influence of probe application pressure on in vitro and in vivo capacitance (Corneometer CM 825®) and conductance (Skicon 200 EX®) measurements

Background/purpose: The measuring probe of the electrical hydration instruments is equipped with a spring system to ensure a constant pressure of probe application on the skin surface. However, it is possible to trigger the measurement at, respectively, a low and a high force of probe application. It is the purpose of this paper to compare the in vitro and in vivo hydration values of the capacitance and conductance method at, respectively, low and high values of application pressure on the considered surface.

Walking with robot assistance: the influence of body weight support on the trunk and pelvis kinematics.

Abstract Purpose: The goal was to assess in healthy participants the three-dimensional kinematics of the pelvis and the trunk during robot-assisted treadmill walking (RATW) at 0%, 30% and 50% body weight support (BWS), compared with treadmill walking (TW). Methods: 18 healthy participants walked (2 kmph) on a treadmill with and without robot assistance (Lokomat; 60% guidance force; 0%, 30% and 50% BWS). After an acclimatisation period (four minutes), trunk and pelvis kinematics were registered in each condition (Polhemus Liberty™ [240 Hz]). The results were analysed using a repeated measures analysis of variance with Bonferroni correction, with the level of suspension as within-subject factor. Results: During RATW with BWS, there were significantly (1) smaller antero-posterior and lateral translations of the trunk and the pelvis; (2) smaller antero-posterior flexion and axial rotation of the trunk; (3) larger lateral flexion of the trunk; and (4) larger antero-posterior tilting of the pelvis compared with TW. Conclusions: There are significant differences in trunk and pelvis kinematics in healthy persons during TW with and without robot assistance. These data are relevant in gait rehabilitation, relating to normal balance regulation. Additional research is recommended to further assess the influence of robot assistance on human gait. Implications for Rehabilitation The trunk and pelvis moves in a different way during walking with robot assistance. The data suggest that the change in movement is due to the robot device and the harness of the suspension system more than due to the level of suspension itself.

Robot-assisted walking with the Lokomat: the influence of different levels of guidance force on thorax and pelvis kinematics.

BACKGROUND Little attention has been devoted to the thorax and pelvis movements during gait. The aim of this study is to compare differences in the thorax and pelvis kinematics during unassisted walking on a treadmill and during walking with robot assistance (Lokomat-system (Hocoma, Volketswil, Switzerland)). METHODS 18 healthy persons walked on a treadmill with and without the Lokomat system at 2kmph. Three different conditions of guidance force (30%, 60% and 100%) were used during robot-assisted treadmill walking (30% body weight support). The maximal movement amplitudes of the thorax and pelvis were measured (Polhemus Liberty™ (Polhemus, Colchester, Vermont, USA) (240/16)). A repeated measurement ANOVA was conducted. FINDINGS Robot-assisted treadmill walking with different levels of guidance force showed significantly smaller maximal movement amplitudes for thorax and pelvis, compared to treadmill walking. Only the antero-posterior tilting of the pelvis was significantly increased during robot-assisted treadmill walking compared to treadmill walking. No significant changes of kinematic parameters were found between the different levels of guidance force. INTERPRETATION With regard to the thorax and pelvis movements, robot-assisted treadmill walking is significantly different compared to treadmill walking. It can be concluded that when using robot assistance, the thorax is stimulated in a different way than during walking without robot assistance, influencing the balance training during gait.

Body weight support during robot-assisted walking: Influence on the trunk and pelvis kinematics

BACKGROUND Efficacy studies concerning robot assisted gait rehabilitation showed limited clinical benefits. A changed kinematic pattern might be responsible for this. Little is known about the kinematics of the trunk and pelvis during robot assisted treadmill walking (RATW). OBJECTIVE The aim of this study was to assess the trunk and pelvis kinematics of healthy subjects during RATW, with different amounts of body weight support (BWS) compared to regular treadmill walking (TW). METHOD Eighteen healthy participants walked on a treadmill, while kinematics were registered by an electromagnetic tracking device. Hereafter, the kinematics of pelvis and trunk were registered during RATW (guidance force 30%) with 0%, 30% and 50% BWS. RESULTS Compared to TW, RATW showed a decrease in the following trunk movements: axial rotation, anteroposterior flexion, lateral and anteroposterior translation. Besides, a decrease in lateral tilting and all translation of the pelvis was found when comparing RATW with TW. Furthermore, the anteroposterior tilting of the pelvis increased during RATW. CONCLUSION In general, there was a decrease in trunk and pelvis movement amplitude during RATW compared with regular TW. Though, it is not known if these changes are responsible for the limited efficacy of robot assisted gait rehabilitation. Further research is indicated.

Determination of the in vivo bioavailability of iontophoretically delivered diclofenac using a methyl nicotinate skin inflammation assay.

Background/aims: In this study, we investigated the bioavailability of iontophoretically delivered diclofenac with the methylnicotinate (MN) test. The inhibition of an erythema provoked by MN is proportional to the bioavailability of diclofenac in the skin. It was our aim to use this procedure in the determination of the contribution of, respectively, passive diffusion, occlusion and electrically assisted delivery during an iontophoretic procedure as used in physiotherapy.