Peter van der Wurff

Females with patellofemoral pain syndrome have weak hip muscles: a systematic review

QUESTION Do females with patellofemoral pain syndrome have decreased hip muscle strength compared with the unaffected side and with healthy controls? DESIGN A systematic review of observational studies published up to January 2008. PARTICIPANTS Females with patellofemoral pain syndrome and healthy controls. OUTCOME MEASURES Strength for at least one hip muscle group had to be included in the study. Hip muscle strength was recorded as force or torque. RESULTS Five cross-sectional studies with a mean Newcastle-Ottawa Assessment Scale score of 6 out of 9 met the inclusion criteria. Strong evidence was found for a deficit in hip external rotation, abduction and extension strength, moderate evidence for a deficit in hip flexion and internal rotation strength, and no evidence for a deficit in hip adduction strength compared with healthy controls. Moderate evidence was found for a decrease in hip external rotation and abduction strength but no evidence for a decrease in hip extension, flexion, adduction and internal rotation strength compared with the unaffected side. CONCLUSION Females with patellofemoral pain syndrome demonstrate a decrease in abduction, external rotation and extension strength of the affected side compared with healthy controls.

Speeding up or slowing down?: Gait adaptations to preserve gait stability in response to balance perturbations

It has frequently been proposed that lowering walking speed is a strategy to enhance gait stability and to decrease the probability of falling. However, previous studies have not been able to establish a clear relation between walking speed and gait stability. We investigated whether people do indeed lower walking speed when gait stability is challenged, and whether this reduces the probability of falling. Nine healthy subjects walked on the Computer Assisted Rehabilitation ENvironment (CAREN) system, while quasi-random medio-lateral translations of the walking surface were imposed at four different intensities. A self-paced treadmill setting allowed subjects to regulate their walking speed throughout the trials. Walking speed, step length, step frequency, step width, local dynamic stability (LDS), and margins of stability (MoS) were measured. Subjects did not change walking speed in response to the balance perturbations (p=0.118), but made shorter, faster, and wider steps (p<0.01) with increasing perturbation intensity. Subjects became locally less stable in response to the perturbations (p<0.01), but increased their MoS in medio-lateral (p<0.01) and backward (p<0.01) direction. In conclusion, not a lower walking speed, but a combination of decreased step length and increased step frequency and step width seems to be the strategy of choice to cope with medio-lateral balance perturbations, which increases MoS and thus decreases the risk of falling.

Stepping strategies for regulating gait adaptability and stability

Besides a stable gait pattern, gait in daily life requires the capability to adapt this pattern in response to environmental conditions. The purpose of this study was to elucidate the anticipatory strategies used by able-bodied people to attain an adaptive gait pattern, and how these strategies interact with strategies used to maintain gait stability. Ten healthy subjects walked in a Computer Assisted Rehabilitation ENvironment (CAREN). To provoke an adaptive gait pattern, subjects had to hit virtual targets, with markers guided by their knees, while walking on a self-paced treadmill. The effects of walking with and without this task on walking speed, step length, step frequency, step width and the margins of stability (MoS) were assessed. Furthermore, these trials were performed with and without additional continuous ML platform translations. When an adaptive gait pattern was required, subjects decreased step length (p<0.01), tended to increase step width (p=0.074), and decreased walking speed while maintaining similar step frequency compared to unconstrained walking. These adaptations resulted in the preservation of equal MoS between trials, despite the disturbing influence of the gait adaptability task. When the gait adaptability task was combined with the balance perturbation subjects further decreased step length, as evidenced by a significant interaction between both manipulations (p=0.012). In conclusion, able-bodied people reduce step length and increase step width during walking conditions requiring a high level of both stability and adaptability. Although an increase in step frequency has previously been found to enhance stability, a faster movement, which would coincide with a higher step frequency, hampers accuracy and may consequently limit gait adaptability.

Stepping strategies used by post-stroke individuals to maintain margins of stability during walking

BACKGROUND People recovering from a stroke are less stable during walking compared to able-bodied controls. The purpose of this study was to examine whether and how post-stroke individuals adapt their steady-state gait pattern to maintain or increase their margins of stability during walking, and to examine how these strategies differ from strategies employed by able-bodied people. METHODS Ten post-stroke individuals and 9 age-matched able-bodied individuals walked on the Computer Assisted Rehabilitation Environment. Medio-lateral translations of the walking surface were imposed to manipulate gait stability. To provoke gait adaptations, a gait adaptability task was used, in which subjects occasionally had to hit a virtual target with their knees. We measured medio-lateral and backward margins of stability, and the associated gait parameters walking speed, step length, step frequency, and step width. FINDINGS Post-stroke participants showed similar medio-lateral margins of stability as able-bodied people in all conditions. This was accomplished by a larger step width and a relatively high step frequency. Post-stroke participants walked overall slower and decreased walking speed and step length even further in response to both manipulations compared to able-bodied participants, resulting in a tendency towards an overall smaller backward margins of stability, and a significantly smaller backward margin of stability during the gait adaptability task. INTERPRETATION Post-stroke individuals have more difficulties regulating their walking speed, and the underlying parameters step frequency and step length, compared to able-bodied controls. These quantities are important in regulating the size of the backward margin of stability when walking in complex environments.

Walking in an Unstable Environment: Strategies Used by Transtibial Amputees to Prevent Falling During Gait

OBJECTIVE To investigate which strategies transtibial amputees use to cope with challenges of gait stability and gait adaptability, and how these strategies differ from strategies used by able-bodied controls. DESIGN Cross-sectional study. SETTING An instrumented treadmill mounted onto a 6°-of-freedom motion platform in combination with a virtual environment. PARTICIPANTS Transtibial amputees (n=10) and able-bodied controls (n=9). INTERVENTIONS Mediolateral (ML) translations of the walking surface were imposed to manipulate gait stability. To provoke an adaptive gait pattern, a gait adaptability task was used in which subjects had to hit virtual targets with markers guided by their knees. MAIN OUTCOME MEASURES Walking speed, step length, step frequency, step width, and selected measures of gait stability (short-term Lyapunov exponents and backward and ML margins of stability [MoS]). RESULTS Amputees walked slower than able-bodied people, with a lower step frequency and wider steps. This resulted in a larger ML MoS but a smaller backward MoS for amputees. In response to the balance perturbation, both groups decreased step length and increased step frequency and step width. Walking speed did not change significantly in response to the perturbation. These adaptations induced an increase in ML and backward MoS. To perform the gait adaptability task, both groups decreased step length and increased step width, but did not change step frequency and walking speed. ML and backward MoS were maintained in both groups. CONCLUSIONS Transtibial amputees have the capacity to use the same strategies to deal with challenges of gait stability and adaptability, to the same extent as able-bodied people.

The Evaluation of Daily Life Activities after Application of an Osseointegrated Prosthesis Fixation in a Bilateral Transfemoral Amputee: A Case Study.

AbstractIndividuals with a transfemoral amputation (TFA) may experience limitations in daily life due to reduced mobility and prosthesis-related problems. An osseointegrated prosthesis fixation (OPF) procedure in amputees might contribute to a solution for patients with short stumps or socket-related problems. To date, no study has specifically described the application of an OPF procedure in individuals with a TFA. This study evaluated the level of daily life activities of a 21-year old service member with a bilateral TFA and cerebral trauma. Due to a short stump length and coordination problems, an OPF procedure was deemed the most suitable option.The result of this procedure and the rehabilitation program showed an increased mobility and satisfaction as obtained by the assessment of life habits questionnaire (LIFE-H) and lower extremity functional scale. The participant was able to walk short distances and the Genium knee provided a stance position. Stair ambulation is impossible because of inadequate muscle capacity.In this specific case we conclude that the quality of life improved through the use of an OPF. However, OPF might not be the appropriate device for every individual with TFA, due to varying bone compositions, co-morbidities, and limited clinical experience and unknown long-term effects.

Stepping Asymmetry Among Individuals With Unilateral Transtibial Limb Loss Might Be Functional in Terms of Gait Stability

Background The asymmetry in step length in prosthetic gait is often seen as a detrimental effect of the impairment; however, this asymmetry also might be a functional compensation. An advantage of a smaller step length of the nonprosthetic leg, and specifically foot forward placement (FFP), might be that it will bring the center of mass closer to the base of support of the leading foot and thus increase the backward margin of stability (BW MoS). Objective The purpose of this study was to characterize differences in step length, FFP, and the concomitant difference in BW MoS between steps of the prosthetic and nonprosthetic legs (referred to as prosthetic and nonprosthetic steps, respectively) of people after transtibial amputation. Design This was an observational and cross-sectional study. Methods Ten people after transtibial amputation walked for 4 minutes on a self-paced treadmill. Step length and FFP were calculated at initial contact. The size of the BW MoS was calculated for the moment of initial contact and at the end of the double-support phase of gait. Results Step length (5.4%) and FFP (7.9%) were shorter for the nonprosthetic step than for the prosthetic step. The BW MoS at initial contact was larger for the nonprosthetic step, but because of a significant leg × gait event interaction effect, BW MoS did not differ significantly at the end of the double-support phase. Limitations All participants were relatively good walkers (score of E on the Special Interest Group in Amputee Medicine [SIGAM] scale). Conclusions The smaller step length and FFP of the nonprosthetic step help to create a larger BW MoS at initial contact for the nonprosthetic step compared with the prosthetic step. Hence, step length asymmetry in people after transtibial amputation might be seen as a functional compensation to preserve BW MoS during the double-support phase to cope with the limited push-off power of the prosthetic ankle.

Chronic low back pain patients with accompanying leg pain: The relationship between pain extent and pain intensity, disability and health status

Accompanying leg pain is commonly observed in patients with chronic low back pain (CLBP) and is assumed to be an indicator for the disorder severity. However, it is still unknown whether it is possible to estimate a patients functional status by the extent of leg pain present. In a post rehabilitation cohort of 132 patients with CLBP (mean age 44.3 years) the relationship between pain extent and functional status was determined using pain drawings scored for pain extent by a simplified scoring system (Lower Extremity Region: LER) and several function related questionnaires. Primary outcomes were pain extent, pain intensity ratings (Visual Analog Scale: VAS), disability status (Oswestry Disability Index: ODI) and physical and mental health (Short Format 12: SF-12). Statistically significant differences between patients with low (1-2) and high (≥ 3) LER scores were found in VAS, ODI and SF-12 physical health scores, however, the LER score has a poor diagnostic accuracy in predicting desirable versus undesirable VAS, ODI and SF-12 scores. Pain intensity (VAS), back disability (ODI) and physical health are worse in CLBP patients with high LER scores. However LER scores cannot be used to predict elevated VAS, ODI and SF-12 scores in an individual patient.

The effect of alignment changes on unilateral transtibial amputee's gait: a systematic review

Introduction Prosthetic alignment, positioning of a prosthetic foot relative to a socket, is an iterative process in which an amputee’s gait is optimized through repetitive optical gait observation and induction of alignment adjustments when deviations are detected in spatiotemporal and kinematic gait parameters. An important limitation of the current prosthetic alignment approach is the subjectivity and the lack of standardized quantifiable baseline values. The purpose of this systematic review is to investigate if an optimal alignment criterion can be derived from published articles. Moreover, we investigated the effect of alignment changes on spatiotemporal, kinematic and kinetic gait parameters. Results A total of 11 studies were included, two controlled before-and-after studies and nine-interrupted time series studies. Discussion The results demonstrate that alignment changes have a predictable influence on the included kinetic parameters. However, the effect of alignment changes on spatio-temporal and kinematic gait parameters are generally unpredictable. These findings suggest that it is imperative to include kinetics in the process of dynamic prosthetic alignment. Partially this can be established by communication with the prosthetic user in terms of perceived socket comfort, but the use of measurement tools should also be considered. While current literature is not conclusive about an optimal alignment, future alignment research should focus on alignment optimisation based on kinetic outcomes.

Prevalence of modic changes in active duty military men with lumbar disk herniation who were scheduled for surgery.

OBJECTIVE The purpose of this study was to report on the prevalence of Modic changes (MCs) in a group of Netherlands military men who were scheduled for surgery (lumbar discectomy). METHODS This was a retrospective observational study of health records. From 133 patients in active military service seen from January 2004 to March, 77 case files were selected. For all subjects who met inclusion criteria, the health records and T1- and T2-weighted magnetic resonance imaging files of lumbar levels L4/L5 and L5-S1 were assessed. Data including age, sex, rank in military, level of lumbar herniation, and level of MC including their types were evaluated. RESULTS Nineteen subjects (24.7%) showed presence of MC at the level of disk herniation, 5 subjects (6.5%) showed MC at a different level, and 10 subjects (13%) showed MC at both levels. In total, 154 segments were analyzed on magnetic resonance imaging for present MC of which 44 levels (28.6%) showed MC type I (31.8%), type II (65.9%), or type III (2.3%). Higher age showed to be significant (P ≤ .001) on developing MC, but no significance was found for physical workload in relation to these changes. CONCLUSIONS For the subjects in this study, MCs were most common at the lower lumbar spine segments, with a predominance of type II. In this study, the presence of a disk herniation and MC at the same level was 37.7%; however, a significant association was not demonstrable.