Maarten R. Prins

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.

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.

Effects of experimentally increased trunk stiffness on thorax and pelvis rotations during walking

Patients with non-specific low back pain, or a similar disorder, may stiffen their trunk, which probably alters their walking coordination. To study the direct effects of increasing trunk stiffness, we experimentally increased trunk stiffness during walking, and compared the results with what is known from the literature about gait coordination with, e.g., low back pain. Healthy subjects walked on a treadmill at 3 speeds (0.5, 1.0 and 1.5m/s), in three conditions (normal, while contracting their abdominal muscles, or wearing an orthopedic brace that limits trunk motions). Kinematics of the legs, thorax and pelvis were recorded, and relative Fourier phases and amplitudes of segment motions were calculated. Increasing trunk stiffness led to a lower thorax-pelvis relative phase, with both a decrease in thorax-leg relative phase, and an increase in pelvis-leg relative phase, as well as reduced rotational amplitude of thorax relative to pelvis. While lower thorax-pelvis relative phase was also found in patients with low back pain, higher pelvis-leg relative phase has never been reported in patients with low back pain or related disorders. These results suggest that increasing trunk stiffness in healthy subjects causes short-term gait coordination changes which are different from those seen in patients with back pain.

STRIDE FREQUENCY AND LENGTH ADJUSTMENT IN POST-STROKE INDIVIDUALS: INFLUENCE ON THE MARGINS OF STABILITY

OBJECTIVE To investigate whether post-stroke participants can walk at different combinations of stride frequency and stride length and how these adaptations affect the backward and medio-lateral margins of stability. SETTING Computer Assisted Rehabilitation Environment (CAREN). PARTICIPANTS Ten post-stroke individuals. INTERVENTION Six trials of 2 min walking on a treadmill at different combinations of stride frequency and stride length. Treadmill speed was set at the corresponding speed, and subjects received visual feedback about the required and actual stride length. OUTCOME MEASURES Mean stride length and frequency and backward and medio-lateral margins of stability for each trial. RESULTS AND CONCLUSION Stroke patients were able to adjust step length when required, but had difficulty adjusting step frequency. When a stride frequency higher than self-selected stride frequency was imposed patients additionally needed to increase stride length in order to match the imposed treadmill speed. For trials at a high stride frequency, in particular, the increase in the backward and medio-lateral margins of stability was limited. In conclusion, training post-stroke individuals to increase stride frequency during walking might give them more opportunities to increase the margins of stability and consequently reduce fall risk.

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.

Combat-related foot injuries: impact on gait and functional outcome

Introduction Prior to deployment of the Netherlands Army Task Force Urozgan in Afghanistan, the Dutch Military and civilian healthcare systems had limited experience in treating blast injuries and their long-term consequences. This meant that guidelines for treatment and rehabilitation were lacking. The aim of this cohort study was to quantify kinematic and kinetic abnormalities in service members with foot injuries in relation to functional outcome using gait analysis. Method In nine service members with combat-related talus, calcaneus and/or navicular bone (TCN) fractures and nine controls, gait parameters were measured using Gait Real-Time Analysis Interactive Lab system. High-level mobility was evaluated by the Comprehensive High-Level Activity Mobility Predictor (CHAMP), and functional ability was assessed by Lower Extremity Functional Scale (LEFS) questionnaire. Results Significant differences were found for LEFS and CHAMP scores (P<0.01), comfortable walking speed and ankle joint range of motion (ROM) (P<0.05), all lower in the group with TCN fractures. For this group, a trend (0.1>P>0.05) for higher step width and lower stride duration and peak power was found. A strong correlation (0.6>r>0.79) is shown between LEFS and comfortable walking speed and CHAMP and ankle joint ROM. The correlations between LEFS and stride duration, step width, ankle joint ROM and peak power, and between CHAMP and comfortable walking speed and stride duration, were moderate (0.4>r>0.59). Conclusions This study demonstrated that service members with TCN fractures, compared with healthy controls, have altered gait characteristics, specifically lower walking speed and ankle joint ROM, both related to lower physical functioning. Patients with bilateral depressed Böhler’s angle had the worse functional performance, and further research is recommended to evaluate the relationship between Böhler’s angle and physical performance. Clinical Trial The Dutch Ministry of Defence (MOD) and the Institutional Review Board and Medical Ethics Review Committee Brabant, The Netherlands, approved this study (P1550).

Evidence of splinting in low back pain? : A systematic review of perturbation studies

PurposeThe purpose of this systematic review was to assess whether LBP patients demonstrate signs of splinting by evaluating the reactions to unexpected mechanical perturbations in terms of (1) trunk muscle activity, (2) kinetic and (3) kinematic trunk responses and (4) estimated mechanical properties of the trunk.MethodsThe literature was systematically reviewed to identify studies that compared responses to mechanical trunk perturbations between LBP patients and healthy controls in terms of muscle activation, kinematics, kinetics, and/or mechanical properties. If more than four studies reported an outcome, the results of these studies were pooled.ResultsNineteen studies were included, of which sixteen reported muscle activation, five kinematic responses, two kinetic responses, and two estimated mechanical trunk properties. We found evidence of a longer response time of muscle activation, which would be in line with splinting behaviour in LBP. No signs of splinting behaviour were found in any of the other outcome measures.ConclusionsWe conclude that there is currently no convincing evidence for the presence of splinting behaviour in LBP patients, because we found no indications for splinting in terms of kinetic and kinematic responses to perturbation and derived mechanical properties of the trunk. Consistent evidence on delayed onsets of muscle activation in response to perturbations was found, but this may have other causes than splinting behaviour.

“Movement of the sacroiliac joint during the active straight leg raise test in patients with long-lasting severe sacroiliac joint pain” : A letter to the editor

_Dear Editor of Clinical Biomechanics,_ We read with interest Kibsgard et al.s above Clinical Biomechanics paper. Radiostereometric Analysis was performed to measure sacroiliac movements during the Active Straight Leg Raise (ASLR) in 12 patients with chronic Pelvic Girdle Pain (PGP). Of the patients, 8 had been diagnosed with bilateral, and 4 with unilateral sacroiliac pain. All were about to undergo sacroiliac fusion surgery. We fully agree with Kibsgard et al. that this is an important field. About 5% of all pregnant women suffer from PGP that is sufficiently serious to warrant medical attention (Wu et al., 2004). Also athletes with groin pain may have PGP (Verrall et al., 2001), often in the form of osteitis pubis. Both groups of patients have difficulties performing the ASLR (Mens et al., 2006). Contralateral to the side of the raising leg, Kibsgard et al. observed 0.8° backward rotation of the ilium with respect to the sacrum (range−0.3° to −1.3°, ‘minus’ for backward), and ipsilaterally on average 0.0° (range −1.0° to +0.5°). We congratulate Kibsgard et al. with this contribution to the field. Still, there are some questions.

Correction: The Effect of Alignment Changes on Unilateral Transtibial Amputee's Gait: A Systematic Review

[This corrects the article DOI: 10.1371/journal.pone.0167466.].