R Senden

Maastricht University, Maestricht, Limburg, Netherlands

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Publications (16)23.08 Total impact

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    ABSTRACT: Shoulder-related dysfunction is the second most common musculoskeletal disorder and is an increasing burden on health-care systems. Commonly used clinical questionnaires suffer from subjectivity, pain dominance and a ceiling effect. Objective functional measurement has been identified as a relevant issue in clinical rehabilitation. Inertia based motion analysis (IMA) is a new generation of objective outcome assessment tool; it can produce objective movement parameters while being fast, cheap and easy to operate. In this prospective study, an inertial sensor comprising a three-dimensional accelerometer and gyroscope is attached at the humerus to measure shoulder movements during two motion tasks in patients with subacromial impingement syndrome at baseline and at five-year after treatment. One hundred healthy subjects served as healthy reference database and 15 patients were measured pre- and post-treatment. IMA was better able to detect improvement in shoulder movements compared to the clinical questionnaires (Disability of Arm, Shoulder and Hand (DASH) and Simple Shoulder Test (SST); p < 0.05) and was hardly correlated with the clinical questionnaires (Pearson R = 0.39). It may therefore add an objective functional dimension to outcome assessment. The fast assessment (t < 5 min) of a simple motion test makes it suitable for routine clinical follow-up.
    Physiological Measurement 03/2014; 35(4):677-686. · 1.50 Impact Factor
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    ABSTRACT: Background The demands of the younger and more active current total knee arthroplasty (TKA) patients are not in line with the current outcome assessments. Therefore, new questionnaires are developed or adjusted, as with the popular 1989 Knee Society Score (KSS). This study is the first to investigate the clinimetric parameters of the patient-reported outcome measurement (PROM) part of the 2011 KSS. Methods Four-hundred-fifteen primary Dutch TKA patients were scored using the PROM part of the 2011 KSS. The scale is subdivided into an Objective (not evaluated), Satisfaction, Expectation and Function subscale. Clinimetric quality was evaluated by response and completion rate, test-retest reliability (n = 29, intraclass correlation coefficient), internal consistency (n = 172, Cronbach’s Alpha), construct validity (Pearson’s correlations with 1989 KSS (n = 75) and KOOS-PS (n = 139)) and responsiveness (n = 20, paired-samples t-test, effect sizes and floor and ceiling effects). Results A response rate of 96% and completion rate of 43% were found. Reliability and internal consistency proved excellent with ICCs ≥ 0.79 and Cronbach’s Alpha ≥ 0.76 for all subscales. Strong correlations were found between the Function subscales of the 2011 KSS and KOOS-PS (r = − 0.60 to − 0.83). All subscales improved significantly after intervention, with exception of Walking & Standing and Discretionary Activities. 23% reached the maximum score postoperatively in Walking & Standing, indicating a ceiling effect. Conclusions The 2011 KSS is a reliable, internal consistent, construct valid and responsive questionnaire to assess the outcome of the Dutch TKA patients. Optimizations (e.g. shortening the scale, simplified design) are recommended to increase the disappointing completion rate.
    The Knee 01/2014; · 2.01 Impact Factor
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    ABSTRACT: Dynamic imbalance caused by external perturbations to gait can successfully be counteracted by adequate recovery responses. The current study investigated how the recovery response is moderated by age, walking speed, muscle strength and speed of information processing. The gait pattern of 50 young and 45 elderly subjects was repeatedly perturbed at 20% and 80% of the first half of the swing phase using the Timed Rapid impact Perturbation (TRiP) set-up. Recovery responses were identified using 2D cameras. Muscular factors (dynamometer) and speed of information processing parameters (computer-based reaction time task) were determined. The stronger, faster reacting and faster walking young subjects recovered more often by an elevating strategy than elderly subjects. Twenty three per cent of the differences in recovery responses were explained by a combination of walking speed (B=-13.85), reaction time (B=-0.82), maximum extension strength (B=0.01) and rate of extension moment development (B=0.19). The recovery response that subjects employed when gait was perturbed by the TRiP set-up was modified by several factors; the individual contribution of walking speed, muscle strength and speed of information processing was small. Insight into remaining modifying factors is needed to assist and optimise fall prevention programmes.
    Gait & posture 09/2013; · 2.58 Impact Factor
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    ABSTRACT: To quantify the effects of subject characteristics on gait parameters using acceleration-based gait analysis. Cross-sectional study with a single group cohort. Hospital setting. One hundred and twenty healthy subjects (six age decade groups of 10 men and 10 women) performed a 20-m walking test. Basic gait parameters (e.g. speed) and other clinically relevant parameters (e.g. step time asymmetry) were assessed during a 20-m walking test using a tri-axial accelerometer, attached at the level of the sacrum. Subject characteristics were recorded. Between 34% and 51% of the variability in gait parameters was explained by age, height and gender. Subject characteristics contributed less to the variance in step time asymmetry (R(2)=0.02), gait irregularity (R(2)=0.07) and vertical displacement of the centre of mass (R(2)=0.17). Relationships identified were comparable with previous studies (e.g. faster walking speed in men, younger and taller subjects). Age, height and gender are determinants of basic gait parameters, while their influence on gait irregularity and step time asymmetry is minimal. This indicates that gait is variable between subjects, showing the relevance of correcting gait for subject characteristics. This study describes preliminary work to build a database of gait parameters in healthy participants, describing the effects of age, gender and height. Further studies to extend this database with patients would provide further relevance to clinical practice.
    Physiotherapy 12/2012; 98(4):325-9. · 1.57 Impact Factor
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    ABSTRACT: This study investigated whether the Tinetti scale, as a subjective measure for fall risk, is associated with objectively measured gait characteristics. It is studied whether gait parameters are different for groups that are stratified for fall risk using the Tinetti scale. Moreover, the discriminative power of gait parameters to classify elderly according to the Tinetti scale is investigated. Gait of 50 elderly with a Tinneti>24 and 50 elderly with a Tinetti≤24 was analyzed using acceleration-based gait analysis. Validated algorithms were used to derive spatio-temporal gait parameters, harmonic ratio, inter-stride amplitude variability and root mean square (RMS) from the accelerometer data. Clear differences in gait were found between the groups. All gait parameters correlated with the Tinetti scale (r-range: 0.20-0.73). Only walking speed, step length and RMS showed moderate to strong correlations and high discriminative power to classify elderly according to the Tinetti scale. It is concluded that subtle gait changes that have previously been related to fall risk are not captured by the subjective assessment. It is therefore worthwhile to include objective gait assessment in fall risk screening.
    Gait & posture 04/2012; 36(2):296-300. · 2.58 Impact Factor
  • Knee Surgery Sports Traumatology Arthroscopy 12/2011; · 2.68 Impact Factor
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    ABSTRACT: In clinical practice, it is increasingly important to assess patients' daily functionality routinely and objectively. Acceleration-based gait analysis (AGA) has shown to be reliable and technically suitable for routine clinical use outside the laboratory. This study investigated the suitability of AGA for measuring function in orthopaedic patients with symptomatic gonarthrosis listed for total knee arthroplasty (TKA) by investigating (a) the ability of AGA to distinguish patients from healthy subjects, (b) the sensitivity to gait changes of AGA in assessing recovery following total knee arthroplasty in a subpopulation, and (c) correlations between AGA parameters and clinical scales. Gait was assessed using AGA in 24 patients with symptomatic gonarthrosis listed for TKA, and in 24 healthy subjects. AGA parameters (e.g. speed, asymmetry) and clinical scales (e.g. KSS) were used to monitor progress in 12 patients 3 months after TKA. The Mann-Whitney-U test, Receiver Operating Characteristic (ROC) curves, repeated measurement ANOVA and Pearson correlations were performed. AGA differentiated pathological from healthy gait. The area under the ROC curve, sensitivity and specificity values were high for speed, step frequency and step length. Different recovery profiles were found, with clinical scales showing faster recovery rates. None or only weak correlations were found between AGA and clinical scores. AGA was found to be of clinical relevance in identifying and monitoring patients with symptomatic gonarthrosis in orthopaedic practice, providing objective and additional information about function beyond clinical scales. This, together with the fact that AGA can be applied routinely, suggests the suitability of AGA for use in rehabilitation programs.
    The Knee 10/2011; 18(5):306-11. · 2.01 Impact Factor
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    ABSTRACT: The aim of this study was to investigate the ability of acceleration-based gait analysis to differentiate between normal gait and different simulated functional knee limitations of increasing severity. Gait of 48 healthy subjects was measured under four different walking conditions. Gait parameters (e.g., speed and asymmetry) were derived from trunk accelerations. Subjects walked a 20-m distance under four conditions: normal, simulated limited knee extension, simulated limited knee flexion, and simulated arthrodesis. The functional knee limitations were simulated using an adjustable knee brace on the right leg. Acceleration-based gait analysis detected acute gait changes (i.e., speed, step length, step duration, cadence, vertical displacement, asymmetry, and irregularity) during the simulated functional knee limitations with high repeatability. The degree of change depended on the severity of the limitation, with the more severe limitations producing bigger changes in gait and the relative changes comparing well with literature values measured with laboratory-based motion analysis. Acceleration-based gait analysis is sensitive for different walking conditions. The easy and fast use, the production of objective gait characteristics, and the ability to differentiate functional knee limitations suggest its suitability for clinical rehabilitation.
    American journal of physical medicine & rehabilitation / Association of Academic Physiatrists 03/2011; 90(3):226-32. · 1.56 Impact Factor
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    ABSTRACT: In total knee arthroplasty, tissue-sparing techniques are considered more important, as functional gain could become more advantageous when early mobilization is commenced. The parapatellar approach is most often used, whereas the subvastus approach is a suitable alternative. Presently, it is unknown, according to true objective measurements, which of the two is most advantageous. In this prospective randomized double-blind, short-term trial measurements (KSS, WOMAC, PDI, VAS, ability to perform) were obtained at day 1, day 3, 1 week, 6 weeks, and 3 months. The subvastus group (n=20) showed only significantly less extension lag direct postoperative (P=0.04) compared with the parapatellar group (n=20). Other scores were not significantly different. The Dynaport®knee test, an objective performance-based tool, could not demonstrate significant differences. A blunt anatomical dissection was carried out in both observational and histological to support findings. A dense innervation of the distal vastus medialis was found. This is at risk employing the subvastus approach. Both approaches harm the suprapatellar bursa. The vastus medialis sheath must be detached distally to open the knee joint. No true separate vastus medialis obliquus could be identified. Comparable to literature, only mild advantage employing the subvastus approach was found, but only early postoperative and not objectively. As this approach is also not suitable in every case, we will continue to use the parapatellar approach.
    Knee Surgery Sports Traumatology Arthroscopy 10/2010; 19(6):943-51. · 2.68 Impact Factor
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    ABSTRACT: Falling is a serious health problem for many elderly. To investigate whether the higher fall incidence in elderly is due to a higher probability of experiencing near falls in daily life, it is necessary to evaluate the stumble incidence of elderly in daily life. Accelerometers are already frequently used for in vivo activity monitoring. The current study investigates whether an ambulant and unobtrusive accelerometer can identify stumbles from treadmill walking using a wavelet based detection approach. Seventy nine healthy subjects walked on a treadmill with a triaxial accelerometer attached at the level of the sacrum. Stumbles were induced using a specially designed braking system (The TRiP). The TRiP evoked 30 stumbles at different phases of the swing phase. A wavelet-based detection algorithm is used to isolate the stumbles from treadmill walking, with a specificity of 99.9% and a sensitivity of 98.4%.
    Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 01/2010; 2010:5018-21.
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    ABSTRACT: Accelerometers enable us to analyse gait outside conventional gait laboratories. Before these devices can be used in large scale studies and in clinical settings a thorough evaluation of their performance in different populations is required. The aim of this study was to present an acceleration-based reference database for healthy gait. The repeatability and inter-observer reliability of acceleration-based gait analysis was investigated. The sensitivity was tested on different age groups and the effect of gender was studied. A comprehensive set of gait parameters (i.e. cadence, speed, asymmetry and irregularity) were studied in 60 women and 60 men. Basic gait parameters showed high repeatability (VC(cadence) 1.51%, ICC(cadence) 0.996) and inter-observer reliability (ICC(cadence) 0.916), while asymmetry and irregularity showed lower repeatability (VC(asym) 47.88%, ICC(asym) 0.787) and inter-observer reliability (ICC(asym) 0.449). The effects of age and gender on gait parameters were found to be consistent with those reported in studies using other methodologies. These findings and the advantages of the device support the application of AGA for routine clinical use and in daily life.
    Gait & posture 06/2009; 30(2):192-6. · 2.58 Impact Factor
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    ABSTRACT: Whether to resurface the patella or not in total knee arthroplasty still remains undecided. Classical scores and questionnaires might not be responsive or demanding enough. This study used two accelerometer based systems to study the hypothesis whether performance based tests are able to detect a difference in patients with or without a resurfaced patella. In this retrospective study 53 patients were included and divided into a resurfaced group (n = 31) and a non-resurfaced group (n = 22). Both groups were matched on age and longevity of follow up. Patients were clinically assessed using the Knee Society Score (KSS) at various time points. At final follow up patients were also assessed once using the Dynaport Knee Test and the Minimod Gait Test. The Dynaport Knee Test showed a significant functional advantage for patients with a resurfaced patella [44 vs. 39.7 (P = 0.042)], whereas KSS and The Minimod were not significant (P values ranging from 0.07 to 0.75). Similar to other reports in literature, using the KSS, it was not possible to identify significant difference between patella resurfacing or retaining in total knee arthroplasty, however using a performance based test it was possible to determine significant difference. The found advantage of patella resurfacing may be less due to pain relief but due to a functional benefit during demanding motion tasks. This finding indicates that current measurement tools may not be accurate or specific enough to detect this difference. Therefore, we recommend complementing the classic evaluation tools with an objective functional test, when conducting a randomized trial to answer the indecision whether to resurface the patella or not.
    Archives of Orthopaedic and Trauma Surgery 06/2008; 129(2):259-65. · 1.36 Impact Factor
  • Journal of Biomechanics. 01/2007; 40:S350.
  • Physiotherapy.
  • Journal of Bone & Joint Surgery, British Volume. 91(SUPP III):454-454.