Several groups have undertaken studies to evaluate the physiologic effects of whole-body vibratio... more Several groups have undertaken studies to evaluate the physiologic effects of whole-body vibration (WBV). However, the value of WBV in a training program remains unknown. To investigate whether a WBV program results in a better strength and postural control performance than an equivalent exercise program performed without vibration. Randomized, controlled trial. Laboratory. Thirty-three Belgian competitive skiers (ages = 9-15 years). Subjects were assigned to either the WBV group or the equivalent resistance (ER) group for 6 weeks of training at 3 times per week. Isokinetic plantar and dorsiflexion peak torque, isokinetic knee flexion and extension peak torque, explosive strength (high box test), and postural control were assessed before and after the training period. Both training programs significantly improved isokinetic ankle and knee muscle strength and explosive strength. Moreover, the increases in explosive strength and in plantar-flexor strength at low speed were significant...
Objective: Excessive frontal plane knee movement during forward lunge movements might be associat... more Objective: Excessive frontal plane knee movement during forward lunge movements might be associated with the occurrence of knee injuries in tennis. Here, we attempt to determine whether hip muscle strength is related to the frontal plane motion of the knee during a functional lunge movement. Design: A correlational study. Participants: A total of 84 healthy subjects (76 men, 8 women), with no history of knee or lower leg complaints.
Journal of orthopaedic research : official publication of the Orthopaedic Research Society, Jan 26, 2016
Hindfoot arthritis is an important contributor to foot pain and physical disability. Whilst the s... more Hindfoot arthritis is an important contributor to foot pain and physical disability. Whilst the subtalar joint (STJ) is most frequently affected, anatomical variants such as facet configuration were suggested to further STJ cartilage deterioration. T2* mapping enables detection of ultra-structural cartilage change, particularly in thin cartilage layers, but its feasibility in the STJ has not yet been evaluated. The purpose of this study was to evaluate segmentation consistency and inter-scan short-term precision error of T2* mapping of talocalcaneal cartilage and to investigate the relationship between facet configuration and STJ T2* values. Using 3Tesla morphological magnetic resonance imaging, STJ configuration was categorized according to the degree of fusion between anterior, medial or posterior facets. Subsequently, 2 repeats of multi-echo gradient recalled echo sequences were performed to obtain T2* maps with repositioning. Segmentation consistency of T2* values attained an IC...
Hip and knee strength abnormalities have been implicated in patellofemoral pain (PFP) in multiple... more Hip and knee strength abnormalities have been implicated in patellofemoral pain (PFP) in multiple studies. However, the relationship is unclear, as many of these studies have been retrospective. To compare prospective hip and knee isokinetic strength in young female athletes who subsequently went on to develop PFP relative to their uninjured, healthy peers. Descriptive epidemiology study. Adolescent female athletes (N = 329) were tested for isokinetic strength of the knee (flexion and extension) and hip (abduction) and screened for the prevalence of PFP before their basketball seasons. After exclusion based on current PFP symptoms, 255 participants were prospectively enrolled in the study. A 1-way analysis of variance was used to determine between-group differences in incident PFP and the referent (no incident PFP) participants. The cumulative incidence rate for the development of PFP was 0.97 per 1000 athlete-exposures. Female athletes who developed PFP demonstrated increased norma...
The American journal of sports medicine, Jan 24, 2016
Running-related hamstring strain injuries remain a delicate issue in several sports such as socce... more Running-related hamstring strain injuries remain a delicate issue in several sports such as soccer. Their unremittingly high incidence and recurrence rates indicate that the underlying risk has not yet been fully identified. Among other factors, the importance of neuromuscular coordination and the quality of interplay between the different hamstring muscle bellies is thought to be a key determinant within the intrinsic injury risk. Muscle functional magnetic resonance imaging (mfMRI) is one of the tools that has been proven to be valid for evaluating intermuscular coordination. To investigate the risk of sustaining an index or recurring soccer-related hamstring injury by exploring metabolic muscle characteristics using mfMRI. Cohort study; Level of evidence, 2. A total of 27 healthy male soccer players and 27 soccer players with a history of hamstring injuries underwent standardized mfMRI. The mfMRI protocol consisted of a resting scan, a strenuous bilateral eccentric hamstring exer...
We investigated the potential prognostic factors for clinically relevant improvements in pain int... more We investigated the potential prognostic factors for clinically relevant improvements in pain intensity and pain-related disability after myofeedback-based teletreatment. Sixty-five female computer users, 56 female patients with whiplash-associated disorders and 18 female patients with non-specific neck and shoulder pain participated in the study. They received myofeedback-based teletreatment or usual treatment. Questionnaires concerning prognostic factors, pain and disability were completed before the start of the intervention (baseline) and at follow-ups at the end of the intervention, and after 3 and 6 months. Logistic regression analyses were performed in order to investigate prognostic factors for clinically relevant improvement. In the intervention group, improvement in pain intensity was predicted by baseline pain intensity. Baseline pain intensity and disability, and fear-avoidance and endurance related pain coping responses were prognostic factors for outcome in pain-relate...
Journal of orthopaedic research : official publication of the Orthopaedic Research Society, Jan 19, 2015
The objectives of this study were as follows: (i) to assess segmentation consistency and scan pre... more The objectives of this study were as follows: (i) to assess segmentation consistency and scan precision of T2* mapping of human tibio-talar cartilage, and (ii) to monitor changes in T2* relaxation times of ankle cartilage immediately following a clinically relevant in vivo exercise and during recovery. Using multi-echo gradient recalled echo sequences, averaged T2* values were calculated for tibio-talar cartilage layers in 10 healthy volunteers. Segmentation consistency and scan precision were determined from two repeated segmentations and two repeated acquisitions with repositioning, respectively. Subsequently, acute in vivo cartilage loading responses were monitored by calculating averaged tibio-talar T2* values at rest, immediately after (i.e., deformation) and at 15 min (i.e., recovery) following a 30-repetition knee bending exercise. Precision errors attained 4-6% with excellent segmentation consistency point estimates (i.e., intra-rater ICC of 0.95) and acceptable limits of co...
Scandinavian Journal of Medicine and Science in Sports, 2006
The meniscus plays an important role in the proprioceptive ability of the knee joint. The aim of ... more The meniscus plays an important role in the proprioceptive ability of the knee joint. The aim of this prospective study was to assess the short-term influence of a meniscus replacement on the proprioception of the knee. Fourteen patients who had undergone a fresh meniscal allograft transplantation between May 2001 and June 2003 were tested preoperatively and 6 months post-operatively. Disability regarding pain, stiffness and functionality of the affected knee during daily activities was measured by the Western Ontario and McMaster Universities Arthritis (WOMAC) scale. The knee joint position sense was assessed using the Biodex System 3 s isokinetic dynamometer. The results of the WOMAC scale showed no significant differences concerning pain, stiffness or knee function between the pre-and post-operative condition of the knee. Assessment of the knee joint position sense at a reference point of 701 of knee flexion revealed a significant improvement of the proprioception of the operated knee at 6 months after surgery compared with the pre-operative condition. The results of this study suggest that although no significant improvement of pain and functionality of the operated knee occurred at this shortterm follow-up period, a meniscal allograft transplantation seems to have a significant positive effect on the joint position sense of the previously meniscectomised knee.
Current multimodal approaches for the management of non-specific patellofemoral pain are not opti... more Current multimodal approaches for the management of non-specific patellofemoral pain are not optimal, however, targeted intervention for subgroups could improve patient outcomes. This study explores whether subgrouping of non-specific patellofemoral pain patients, using a series of low cost simple clinical tests, is possible. The exclusivity and clinical importance of potential subgroups was assessed by applying à priori test thresholds (1 SD) from seven clinical tests in a sample of adult patients with non-specific patellofemoral pain. Hierarchical clustering and latent profile analysis, were used to gain additional insights into subgroups using data from the same clinical tests. 130 participants were recruited, 127 had complete data: 84 (66%) female, mean age 26 years (SD 5.7) and mean body mass index 25.4 (SD 5.83), median (IQR) time between onset of pain and assessment was 24 (7-60) months. Potential subgroups defined by the à priori test thresholds were not mutually exclusive a...
Samenvatting Algemeen wordt aanvaard dat het verhogen van de lenigheid van het musculoskeletale ... more Samenvatting Algemeen wordt aanvaard dat het verhogen van de lenigheid van het musculoskeletale stelsel prestatiebevorderend werkt en de kans op letsels vermindert. Daarom worden stretching- of rekoefeningen dikwijls geïntegreerd in de warming-up en cooling-down. Uit de literatuur blijkt echter dat niet alle wetenschappers het erover eens zijn dat de positieve eigenschappen die aan rekken worden toegeschreven waar zijn. Klaarblijkelijk is er onvoldoende wetenschappelijke onderbouwing en kunnen er geen duidelijke conclusies worden getrokken over de relatie tussen rekoefeningen en sportblessures.
Objective: To longitudinally estimate the change in glycosaminoglycan content of knee cartilage i... more Objective: To longitudinally estimate the change in glycosaminoglycan content of knee cartilage in asymptomatic untrained female novice runners participating in a Start To Run program (STR) compared to sedentary controls. Method: Nine females enrolling in a 10-week STR and 10 sedentary controls participated voluntarily. Prior to and after the 10-week period, both groups were subjected to dGEMRIC imaging. dGEMRIC indices of knee cartilage were determined at baseline and for the change after the 10-week period in both groups. Based on a self-reported weekly log, physical activity change during the study was depicted as decreased, unchanged or increased. The ManneWhitney U and KruskaleWallis tests were applied to test the hypotheses that dGEMRIC changes occurred between groups and according to physical activity changes respectively. Results: No significant differences were established between groups for dGEMRIC indices at baseline (P ¼ 0.541). A significant positive change of the median dGEMRIC index in the runners group was demonstrated when compared to the controls [þ11.66 ms (95% CI: À25.29, 44.43) vs À9.56 ms (95% CI: À29.55, 5.83), P ¼ 0.006]. The change in dGEMRIC index differed significantly according to physical activity change (P ¼ 0.014), showing an increase in dGEMRIC index with increasing physical activity. Conclusion: Since cartilage appears to positively respond to moderate running when compared to a sedentary lifestyle, this running scheme might be considered a valuable tool in osteoarthritis prevention strategies. Caution is warranted when applying these results to a wider population and to longer training periods.
Objective: To summarize the current evidence of magnetic resonance imaging (MRI)-measured cartila... more Objective: To summarize the current evidence of magnetic resonance imaging (MRI)-measured cartilage adaptations following anterior cruciate ligament (ACL) reconstruction and of the potential factors that might influence these changes, including the effect of treatment on the course of cartilage change (i.e., surgical vs non-surgical treatment). Methods: A literature search was conducted in seven electronic databases extracting 12 full-text articles. These articles reported on in vivo MRI-related cartilage longitudinal follow-up after ACL injury and reconstruction in "young" adults. Eligibility and methodological quality was rated by two independent reviewers. A best-evidence synthesis was performed for reported factors influencing cartilage changes.
Purpose: A dysfunction of the quadriceps muscle group has often been suggested to play an importa... more Purpose: A dysfunction of the quadriceps muscle group has often been suggested to play an important role in the pathophysiology of patellofemoral pain (PFP). However, consensus is lacking regarding the quadriceps recruitment pattern of patients with PFP. The aim of this study is to examine by muscle functional magnetic resonance imaging (mfMRI) if PFP patients actually exhibit an altered activation of the muscles that play a significant role in the dynamic balance of the patella.
Several groups have undertaken studies to evaluate the physiologic effects of whole-body vibratio... more Several groups have undertaken studies to evaluate the physiologic effects of whole-body vibration (WBV). However, the value of WBV in a training program remains unknown. To investigate whether a WBV program results in a better strength and postural control performance than an equivalent exercise program performed without vibration. Randomized, controlled trial. Laboratory. Thirty-three Belgian competitive skiers (ages = 9-15 years). Subjects were assigned to either the WBV group or the equivalent resistance (ER) group for 6 weeks of training at 3 times per week. Isokinetic plantar and dorsiflexion peak torque, isokinetic knee flexion and extension peak torque, explosive strength (high box test), and postural control were assessed before and after the training period. Both training programs significantly improved isokinetic ankle and knee muscle strength and explosive strength. Moreover, the increases in explosive strength and in plantar-flexor strength at low speed were significant...
Objective: Excessive frontal plane knee movement during forward lunge movements might be associat... more Objective: Excessive frontal plane knee movement during forward lunge movements might be associated with the occurrence of knee injuries in tennis. Here, we attempt to determine whether hip muscle strength is related to the frontal plane motion of the knee during a functional lunge movement. Design: A correlational study. Participants: A total of 84 healthy subjects (76 men, 8 women), with no history of knee or lower leg complaints.
Journal of orthopaedic research : official publication of the Orthopaedic Research Society, Jan 26, 2016
Hindfoot arthritis is an important contributor to foot pain and physical disability. Whilst the s... more Hindfoot arthritis is an important contributor to foot pain and physical disability. Whilst the subtalar joint (STJ) is most frequently affected, anatomical variants such as facet configuration were suggested to further STJ cartilage deterioration. T2* mapping enables detection of ultra-structural cartilage change, particularly in thin cartilage layers, but its feasibility in the STJ has not yet been evaluated. The purpose of this study was to evaluate segmentation consistency and inter-scan short-term precision error of T2* mapping of talocalcaneal cartilage and to investigate the relationship between facet configuration and STJ T2* values. Using 3Tesla morphological magnetic resonance imaging, STJ configuration was categorized according to the degree of fusion between anterior, medial or posterior facets. Subsequently, 2 repeats of multi-echo gradient recalled echo sequences were performed to obtain T2* maps with repositioning. Segmentation consistency of T2* values attained an IC...
Hip and knee strength abnormalities have been implicated in patellofemoral pain (PFP) in multiple... more Hip and knee strength abnormalities have been implicated in patellofemoral pain (PFP) in multiple studies. However, the relationship is unclear, as many of these studies have been retrospective. To compare prospective hip and knee isokinetic strength in young female athletes who subsequently went on to develop PFP relative to their uninjured, healthy peers. Descriptive epidemiology study. Adolescent female athletes (N = 329) were tested for isokinetic strength of the knee (flexion and extension) and hip (abduction) and screened for the prevalence of PFP before their basketball seasons. After exclusion based on current PFP symptoms, 255 participants were prospectively enrolled in the study. A 1-way analysis of variance was used to determine between-group differences in incident PFP and the referent (no incident PFP) participants. The cumulative incidence rate for the development of PFP was 0.97 per 1000 athlete-exposures. Female athletes who developed PFP demonstrated increased norma...
The American journal of sports medicine, Jan 24, 2016
Running-related hamstring strain injuries remain a delicate issue in several sports such as socce... more Running-related hamstring strain injuries remain a delicate issue in several sports such as soccer. Their unremittingly high incidence and recurrence rates indicate that the underlying risk has not yet been fully identified. Among other factors, the importance of neuromuscular coordination and the quality of interplay between the different hamstring muscle bellies is thought to be a key determinant within the intrinsic injury risk. Muscle functional magnetic resonance imaging (mfMRI) is one of the tools that has been proven to be valid for evaluating intermuscular coordination. To investigate the risk of sustaining an index or recurring soccer-related hamstring injury by exploring metabolic muscle characteristics using mfMRI. Cohort study; Level of evidence, 2. A total of 27 healthy male soccer players and 27 soccer players with a history of hamstring injuries underwent standardized mfMRI. The mfMRI protocol consisted of a resting scan, a strenuous bilateral eccentric hamstring exer...
We investigated the potential prognostic factors for clinically relevant improvements in pain int... more We investigated the potential prognostic factors for clinically relevant improvements in pain intensity and pain-related disability after myofeedback-based teletreatment. Sixty-five female computer users, 56 female patients with whiplash-associated disorders and 18 female patients with non-specific neck and shoulder pain participated in the study. They received myofeedback-based teletreatment or usual treatment. Questionnaires concerning prognostic factors, pain and disability were completed before the start of the intervention (baseline) and at follow-ups at the end of the intervention, and after 3 and 6 months. Logistic regression analyses were performed in order to investigate prognostic factors for clinically relevant improvement. In the intervention group, improvement in pain intensity was predicted by baseline pain intensity. Baseline pain intensity and disability, and fear-avoidance and endurance related pain coping responses were prognostic factors for outcome in pain-relate...
Journal of orthopaedic research : official publication of the Orthopaedic Research Society, Jan 19, 2015
The objectives of this study were as follows: (i) to assess segmentation consistency and scan pre... more The objectives of this study were as follows: (i) to assess segmentation consistency and scan precision of T2* mapping of human tibio-talar cartilage, and (ii) to monitor changes in T2* relaxation times of ankle cartilage immediately following a clinically relevant in vivo exercise and during recovery. Using multi-echo gradient recalled echo sequences, averaged T2* values were calculated for tibio-talar cartilage layers in 10 healthy volunteers. Segmentation consistency and scan precision were determined from two repeated segmentations and two repeated acquisitions with repositioning, respectively. Subsequently, acute in vivo cartilage loading responses were monitored by calculating averaged tibio-talar T2* values at rest, immediately after (i.e., deformation) and at 15 min (i.e., recovery) following a 30-repetition knee bending exercise. Precision errors attained 4-6% with excellent segmentation consistency point estimates (i.e., intra-rater ICC of 0.95) and acceptable limits of co...
Scandinavian Journal of Medicine and Science in Sports, 2006
The meniscus plays an important role in the proprioceptive ability of the knee joint. The aim of ... more The meniscus plays an important role in the proprioceptive ability of the knee joint. The aim of this prospective study was to assess the short-term influence of a meniscus replacement on the proprioception of the knee. Fourteen patients who had undergone a fresh meniscal allograft transplantation between May 2001 and June 2003 were tested preoperatively and 6 months post-operatively. Disability regarding pain, stiffness and functionality of the affected knee during daily activities was measured by the Western Ontario and McMaster Universities Arthritis (WOMAC) scale. The knee joint position sense was assessed using the Biodex System 3 s isokinetic dynamometer. The results of the WOMAC scale showed no significant differences concerning pain, stiffness or knee function between the pre-and post-operative condition of the knee. Assessment of the knee joint position sense at a reference point of 701 of knee flexion revealed a significant improvement of the proprioception of the operated knee at 6 months after surgery compared with the pre-operative condition. The results of this study suggest that although no significant improvement of pain and functionality of the operated knee occurred at this shortterm follow-up period, a meniscal allograft transplantation seems to have a significant positive effect on the joint position sense of the previously meniscectomised knee.
Current multimodal approaches for the management of non-specific patellofemoral pain are not opti... more Current multimodal approaches for the management of non-specific patellofemoral pain are not optimal, however, targeted intervention for subgroups could improve patient outcomes. This study explores whether subgrouping of non-specific patellofemoral pain patients, using a series of low cost simple clinical tests, is possible. The exclusivity and clinical importance of potential subgroups was assessed by applying à priori test thresholds (1 SD) from seven clinical tests in a sample of adult patients with non-specific patellofemoral pain. Hierarchical clustering and latent profile analysis, were used to gain additional insights into subgroups using data from the same clinical tests. 130 participants were recruited, 127 had complete data: 84 (66%) female, mean age 26 years (SD 5.7) and mean body mass index 25.4 (SD 5.83), median (IQR) time between onset of pain and assessment was 24 (7-60) months. Potential subgroups defined by the à priori test thresholds were not mutually exclusive a...
Samenvatting Algemeen wordt aanvaard dat het verhogen van de lenigheid van het musculoskeletale ... more Samenvatting Algemeen wordt aanvaard dat het verhogen van de lenigheid van het musculoskeletale stelsel prestatiebevorderend werkt en de kans op letsels vermindert. Daarom worden stretching- of rekoefeningen dikwijls geïntegreerd in de warming-up en cooling-down. Uit de literatuur blijkt echter dat niet alle wetenschappers het erover eens zijn dat de positieve eigenschappen die aan rekken worden toegeschreven waar zijn. Klaarblijkelijk is er onvoldoende wetenschappelijke onderbouwing en kunnen er geen duidelijke conclusies worden getrokken over de relatie tussen rekoefeningen en sportblessures.
Objective: To longitudinally estimate the change in glycosaminoglycan content of knee cartilage i... more Objective: To longitudinally estimate the change in glycosaminoglycan content of knee cartilage in asymptomatic untrained female novice runners participating in a Start To Run program (STR) compared to sedentary controls. Method: Nine females enrolling in a 10-week STR and 10 sedentary controls participated voluntarily. Prior to and after the 10-week period, both groups were subjected to dGEMRIC imaging. dGEMRIC indices of knee cartilage were determined at baseline and for the change after the 10-week period in both groups. Based on a self-reported weekly log, physical activity change during the study was depicted as decreased, unchanged or increased. The ManneWhitney U and KruskaleWallis tests were applied to test the hypotheses that dGEMRIC changes occurred between groups and according to physical activity changes respectively. Results: No significant differences were established between groups for dGEMRIC indices at baseline (P ¼ 0.541). A significant positive change of the median dGEMRIC index in the runners group was demonstrated when compared to the controls [þ11.66 ms (95% CI: À25.29, 44.43) vs À9.56 ms (95% CI: À29.55, 5.83), P ¼ 0.006]. The change in dGEMRIC index differed significantly according to physical activity change (P ¼ 0.014), showing an increase in dGEMRIC index with increasing physical activity. Conclusion: Since cartilage appears to positively respond to moderate running when compared to a sedentary lifestyle, this running scheme might be considered a valuable tool in osteoarthritis prevention strategies. Caution is warranted when applying these results to a wider population and to longer training periods.
Objective: To summarize the current evidence of magnetic resonance imaging (MRI)-measured cartila... more Objective: To summarize the current evidence of magnetic resonance imaging (MRI)-measured cartilage adaptations following anterior cruciate ligament (ACL) reconstruction and of the potential factors that might influence these changes, including the effect of treatment on the course of cartilage change (i.e., surgical vs non-surgical treatment). Methods: A literature search was conducted in seven electronic databases extracting 12 full-text articles. These articles reported on in vivo MRI-related cartilage longitudinal follow-up after ACL injury and reconstruction in "young" adults. Eligibility and methodological quality was rated by two independent reviewers. A best-evidence synthesis was performed for reported factors influencing cartilage changes.
Purpose: A dysfunction of the quadriceps muscle group has often been suggested to play an importa... more Purpose: A dysfunction of the quadriceps muscle group has often been suggested to play an important role in the pathophysiology of patellofemoral pain (PFP). However, consensus is lacking regarding the quadriceps recruitment pattern of patients with PFP. The aim of this study is to examine by muscle functional magnetic resonance imaging (mfMRI) if PFP patients actually exhibit an altered activation of the muscles that play a significant role in the dynamic balance of the patella.
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Papers by Erik Witvrouw