Whole-body kinematics of squats two decades following anterior cruciate ligament injury.

BACKGROUND: Kinematic studies suggest that injury of the anterior cruciate ligament (ACL) leads to long-lasting movement deficits or compensations to unload the injured knee. This study evaluated lower body kinematics during squats in individuals who suffered unilateral ACL-injury more than 20 years ago. METHOD: Using motion capture, we compared maximum squat depth, time to complete the squat task, detailed kinematics, estimated kinetic-chain joint moments 0- 80° knee flexion, and weight distribution between legs across three groups with (ACLR, n = 27) and without ACL-reconstructive surgery (ACLPT, physiotherapy only, n = 28), and age-matched non-injured asymptomatic Controls (n = 31, average age across groups 47 years). RESULTS: ACLPT demonstrated significantly reduced squat depth compared to Controls (p = 0.004), whereas ACLR performed similarly to Controls (p = 1.000). Other outcome variables were comparable between groups. All participants nevertheless demonstrated asymmetric weight distribution between legs but without systematic unloading of the injured side in the ACLgroups. CONCLUSION: Expected compensatory strategies were not found in the ACL-groups, while poorer squat performance in the ACL-deficient group may depend on pure knee-joint mechanics, or lifestyle factors attributed to a less stable knee decades after ACL-injury.

Physiotherapy and its service in Nepal: implementation and status reported from facility surveys and official registers.

BACKGROUND: Physiotherapy is a growing profession in Nepal. Despite efforts to promote strengthening and development, there are still challenges in providing equitable access and availability to services, particularly in underserved areas. Updated information is needed to address challenges to provide proper planning for resource allocation. OBJECTIVE: To assess implementation of physiotherapy services and to explore plans, policies and the general status of physiotherapy in Nepal. METHOD: Implementation was assessed with a cross-sectional survey conducted in Province III containing closed-ended questions addressing physiotherapy services, human resources, charging and record-keeping systems, and accessibility. Stratified purposive sampling was used to select eligible facilities from the list of Department of Health Services. Official records were explored through visits to governing institutions and by reviews of registers and reports to obtain data and information on status, plans and policy. RESULTS: The survey included 25 urban and 4 rural facilities, covering hospitals and rehabilitation centres; both public (37.9%) and non-public (62.1%). Most facilities (79.3%) employed physiotherapists with bachelor's degrees. Average number of visits were 29.55 physiotherapy outpatients and 14.17 inpatients per day. Patient records were mainly paper based. Most (69%) used the hospital main card, while others (31%) had their own physiotherapy assessment card. Most referrals came from doctors. The most offered services were musculoskeletal, neurological, and paediatric physiotherapy. Daily basis charging was common. A single visit averaged 311 Nepalese rupees ≈ 2.33 US$. Convenience for persons with disabilities was reported as partial by 79% of outpatient departments. Official register data showed 313 master's and 2003 bachelor's graduates. Six colleges offered physiotherapy bachelor's degree, whereof one also offered a master's program. Government records revealed significant progress in physiotherapy in Nepal. CONCLUSION: The study highlights variations in physiotherapy services within a province owing to type, size and location, but also unwarranted variations. Despite the progress, implementation of physiotherapy services in the perspective of official records imply a need of systems for proper planning and monitoring. Physiotherapy provision in underserved areas warrants further attention.

Factors associated with self-rated difficulty to descend stairs in persons with knee osteoarthritis.

BACKGROUND: Difficulty descending stairs is common in persons with knee osteoarthritis (OA). Clinically, it is important to know if and how this is explained by objectively measured difficulty to descend stairs, muscle weakness, pain, fear of movement, or knee joint status. OBJECTIVE: To identify the potential of these factors to explain self-reported difficulty descending stairs. DESIGN: Cross sectional, case-control. SETTING: Hospital outpatient and physiotherapy clinic. PARTICIPANTS: Twenty-eight men and women with knee OA (age 62.2 SD 5.9 years) and 31 controls (age 50.0 SD 8.5 years). INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: Using multivariate statistics, group comparisons were made for lower extremity kinematics (incorporating hip, knee, and ankle angles) and stance time in stair descent and lower extremity muscle strength. Then, a stepwise linear regression analysis was performed within the OA group to explain self-reported difficulties in stair descent where pain, kinesiophobia, radiographic signs, and outcomes that differed from controls for stair-descent kinematics and muscle strength were independent variables. RESULTS: Multivariate statistics showed that the OA group displayed different all-over lower extremity kinematics (F8,42 = 2.44 p = .029, η2  = 0.32) and a longer stance time (F3,50 = 6.46; p = .001, η2  = 0.28) in stair descent and lower muscle strength (F7,47 = 2.39; p = .035, η2  = 0.26) compared to controls. Regression analysis within the OA group to explain self-rated difficulties to descend stairs showed that the strongest association with kinesiophobia (ß = 0.607, p = .001) that combined with pain last week and radiographic signs explained almost 100% (ß = 0.972). Stair descent kinematics and strength variables that differed between groups did not explain self-rated difficulties to descend stairs. CONCLUSION: Kinesiophobia and pain rather than stair-descent kinematics and reduced muscle-strength explained self-rated difficulties in stair descent in the OA group.

Modeling Movement-Induced Errors in AC Electromagnetic Trackers.

Error analysis of electromagnetic motion tracking systems is of growing interest to many researchers. Under sensor movement, it is logical to presume that the error in position and orientation measurements will increase due to the linearization used in the algorithms, among other reasons. In this article, we analyze theoretically the error, that results from linearization, in position measurement of the Polhemus tracking system for a moving sensor. We derive formulas to estimate this error in terms of the sensor position and speed. Then, we verify these formulas by numerical simulations.

Relevance of anthropometric measurements as predictors of prevalent diabetes type 2: a cross-sectional study on a Norwegian population.

OBJECTIVES: The objective was to determine the predictive potential of anthropometric indices to screen prevalent diabetes mellitus type 2 in a Norwegian population. DESIGN: This is a cross-sectional design to determine the potential association of waist-to-height ratio (WHtR), waist-to-hip ratio (WHR), waist circumference (WC) and body mass index (BMI) with prevalent diabetes mellitus type 2 through logistic regression analysis. Receiver operating characteristic (ROC) curves were used to determine the predictive potential of the anthropometric indices. Youden's index was applied to determine the optimal cut-off points for each anthropometric index. SETTING: This study used cross-sectional data from the populations-based Health Study in Nord-Trøndelag which invited all citizens in the county above 20 years of age. PARTICIPANTS: This study included all those who were non-pregnant and had complete data (N=50 042), 98.5% of the participants. The sample is to be considered representative for the population of Norway. PRIMARY AND SECONDARY OUTCOME MEASURES: OR and ROC of the potential association between diabetes mellitus type 2 and anthropometric indices were the main planned and performed outcome measures. RESULTS: The results suggest that the anthropometric indices performed differently within the Norwegian population with WHR and WHtR being the stronger predictor with (ROC) of 0.746 (0.735 to 0.757) and 0.741 (0.730 to 0.752). The predictive potential for the investigated anthropometric indices was generally stronger for women than men. CONCLUSION: Anthropometric indices of size BMI and the highly correlated WC are less associated with prevalent diabetes mellitus type 2 than WHR (WC adjusted for hip circumference) or WHtR (WC adjusted for height) in a Norwegian population.

Pregnant women's experiences with a pelvic floor muscle training program in Nepal.

BACKGROUND: In Nepal, pelvic floor disorders affect about 24% of the women in reproductive age whereof 10% suffer from pelvic organ prolapse (POP). Still, many do not seek health care. Strengthening exercises for the pelvic floor muscles for prevention and treatment of POP has shown strong evidence internationally, but for women in Nepal surgery is primarily offered. To amend this, a novel pelvic floor muscle training (PFMT) program for pregnant women was introduced. OBJECTIVE: To learn about how the PFMT-program was received by the participating women, their understanding of the importance of doing the exercises, and the constraints of daily life for performing the program. METHODS: A qualitative study design based on a sub-sample (N = 10) from a strategic sample (N = 235) who participated in the PFMT-program. Ten semi-structured in-depth interviews were interpreted according to a phenomenological analytical tradition. RESULTS: The 10 women were representative for the women who had participated in the PFMT-program with regard to urban residence, socioeconomic, and educational standing. The program was well received and compliance satisfactory. In line with the PFMT's learning outcomes, the women described risk factors, showed knowledge about the pelvic floor muscles, and understood the importance of doing the exercises. They had managed to fit the exercises into their busy daily routines. Meeting peers in exercise groups and understanding from family were positive factors for compliance. CONCLUSION: The Nepalese women appear interested in self-care and are making an effort to fit the exercises into their busy schedule. Although the communicative validity was satisfactory, the pragmatic validity cannot be generalized to women in rural areas and under less fortunate socioeconomic and educational circumstances.

Rigid head-neck responses to unpredictable perturbations in patients with long standing neck pain does not change with treatment.

In a previous study we have shown that patients with long standing non-specific neck-pain display more rigid neck movement behavior than controls in response to unpredictable perturbations. In the present study we investigated head/neck motor control in patients with neck-pain during a course of physiotherapy intervention and the associations with pain, neck disability and kinesiophobia. In this longitudinal observational study, 72 patients with non-specific neck-pain were exposed to unpredictable horizontal rotations by means of an actuated chair in three conditions; with a visual reference, and without vision with and without a cognitive task before first consultation with physiotherapist, after 2 weeks and 2 months of intervention. The neck movements were analyzed in the frequency domain to cover voluntarily and reflex controlled responses. Questionnaires encompassed Neck Disability Index, Tampa Scale of Kinesiophobia, and the Numerical Rating Scale for current pain. The results showed that the response pattern for the amplitudes of movement between head and trunk across frequencies did not change over time, whereas some changes in timing were found for some frequencies. Pain, neck disability, and kinesiophobia improved after intervention, but were not significantly associated with neck movement responses to perturbations across time or condition. Although physiotherapy intervention improved self-reported function, the rigid responses to unpredictable perturbations remained unchanged. This indicates altered function in reflex mediated control mechanisms, i.e., the vestibulocollic and the cervicocollic reflex systems that control the head in space and on the trunk. Future research should further investigate pain related changes in reflex systems and whether alterations in these systems are modifiable.

Neuropsychological dysfunction in chronic fatigue syndrome and the relation between objective and subjective findings.

OBJECTIVE: This study aimed to explore the relationship between self-reported cognitive difficulties, objective neuropsychological test performances, and subjective health complaints in chronic fatigue syndrome (CFS) and to examine the degree of impaired cognitive functions. METHOD: A total of 236 consecutively recruited outpatients, 18-62 years of age, completed the tests. Self-administered questionnaires were used for assessing fatigue, pain, depression, anxiety and subjective cognitive complaints (Everyday Memory Questionnaire [EMQ]). Also, neuropsychological tests, that is, Stroop I-IV, California Verbal Learning Test-Second Edition (CVLT-II) learning and delay, Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) Letter Number (L-N) Sequencing, and the Paced Auditory Serial Addition Task were performed to examine whether these objective measures correlated with subjective complaints and were compared with normative data. RESULTS: There was a trend of association (p < .05) between the unadjusted EMQ with Stroop IV (inhibition and shifting attention), the CVLT-II learning and delay (verbal learning and memory), and the WAIS-III L-N Sequencing (working memory), but none were statistically significant at the .001 level. The EMQ was positively associated with fatigue, pain, and depression (p < .001). The PASAT (working memory) was negatively associated with pain (p < .001). Between 21% and 38% of the patients performed below the 1.5-SD cutoff for clinically significant impairment on the Stroop tests. CONCLUSION: The self-reported cognitive performance was not strongly associated with the objective cognitive performances on any domains in patients with CFS. Patients with higher fatigue, pain, and depression levels reported greater subjective cognitive difficulties, as well as higher pain related to lower objective working memory function. The CFS patients had problems mainly in the domains of psychomotor speed and attention measured by the objective neuropsychological tests. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Health Competency Standards in Physical Therapist Practice.

Although the physical therapist profession is the leading established, largely nonpharmacological health profession in the world and is committed to health promotion and noncommunicable disease (NCD) prevention, these have yet to be designated as core physical therapist competencies. Based on findings of 3 Physical Therapy Summits on Global Health, addressing NCDs (heart disease, cancer, hypertension, stroke, diabetes, obesity, and chronic lung disease) has been declared an urgent professional priority. The Third Summit established the status of health competencies in physical therapist practice across the 5 World Confederation for Physical Therapy (WCPT) regions with a view to establish health competency standards, this article's focus. Three general principles related to health-focused practice emerged, along with 3 recommendations for its inclusion. Participants acknowledged that specific competencies are needed to ensure that health promotion and NCD prevention are practiced consistently by physical therapists within and across WCPT regions (ie, effective counseling for smoking cessation, basic nutrition, weight control, and reduced sitting and increased activity/exercise in patients and clients, irrespective of their presenting complaints/diagnoses). Minimum accreditable health competency standards within the profession, including use of the WCPT-supported Health Improvement Card, were recommended for inclusion into practice, entry-to-practice education, and research. Such standards are highly consistent with the mission of the WCPT and the World Health Organization. The physical therapist profession needs to assume a leadership role vis-à-vis eliminating the gap between what we know unequivocally about the causes of and contributors to NCDs and the long-term benefits of effective, sustained, nonpharmacological lifestyle behavior change, which no drug nor many surgical procedures have been reported to match.

Frequency-dependent deficits in head steadiness in patients with nonspecific neck pain.

Motor control impairments are reported in patients with nonspecific neck pain but the particular deficits in underlying regulatory systems are not known. Head steadiness is controlled both by voluntary and reflex systems that are predominantly effective within different frequency intervals. The aim of the present study was to investigate within which frequency range(s) potential motor control deficits may reside. The ability to keep the head stationary in space in response to unpredictable perturbations was tested in 71 patients with nonspecific neck pain and 17 healthy controls. Participants were exposed to pseudorandom horizontal rotations across 10 superimposed frequencies (0.185-4.115 Hz) by means of an actuated chair in three conditions; with a visual reference, and without vision with, and without a cognitive task. Below 1 Hz, patients kept the head less stable in space compared to healthy controls. Between 1 and 2 Hz, the head was stabilized on the trunk in both groups. Patients kept the head more stable relative to the trunk than relative to space compared to healthy controls. This was interpreted as higher general neck muscle co-activation in patients, which may be explained by altered voluntary control, or/and upregulated gamma motor neuron activity which increases the contribution of reflex-mediated muscle activation. Alternatively, increased muscle activity is secondary to vestibular deficits.

A Concurrent Cognitive Task Does Not Perturb Quiet Standing in Fibromyalgia and Chronic Fatigue Syndrome.

Background and Objectives: Cognitive complaints are common in fibromyalgia (FM) and chronic fatigue syndrome (CFS). Fatigue as well as pain may require greater effort to perform cognitive tasks, thereby increasing the load on processing in the central nervous system and interfering with motor control. Methods: The effect of a concurrent arithmetic cognitive task on postural control during quiet standing was investigated in 75 women (aged 19-49 years) and compared between FM, CFS, and matched controls (n=25/group). Quiet standing on a force plate was performed for 60 s/condition, with and without a concurrent cognitive task. The center of pressure data was decomposed into a slow component and a fast component representing postural sway and adjusting ankle torque. Results: Compared to controls, CFS and FM displayed lower frequency in the slow component (p < 0.001), and CFS displayed greater amplitude in the slow (p=0.038 and p=0.018) and fast (p=0.045) components. There were no interactions indicating different responses to the added cognitive task between any of the three groups. Conclusion: Patients displayed insufficient postural control across both conditions, while the concurrent cognitive task did not perturb quiet standing. Fatigue but not pain correlated with postural control variables.

Lower regulatory frequency for postural control in patients with fibromyalgia and chronic fatigue syndrome.

As many similar symptoms are reported in fibromyalgia (FM) and chronic fatigue syndrome (CFS), underlying defcits may potentially also be similar. Postural disequilibrium reported in both conditions may thus be explained by similar deviations in postural control strategies. 75 females (25/group FM, CFS and control, age 19-49 years) performed 60 s of quiet standing on a force platform in each of three conditions: 1) firm surface with vision, 2) firm surface without vision and, 3) compliant surface with vision. Migration of center of pressure was decomposed into a slow and a fast component denoting postural sway and lateral forces controlling postural sway, analyzed in the time and frequency domains. Main effects of group for the antero-posterior (AP) and medio-lateral (ML) directions showed that patients displayed larger amplitudes (AP, p = 0.002; ML, p = 0.021) and lower frequencies (AP, p < 0.001; ML, p < 0.001) for the slow component, as well as for the fast component (amplitudes: AP, p = 0.010; ML, p = 0.001 and frequencies: AP, p = 0.001; ML, p = 0.029) compared to controls. Post hoc analyses showed no significant differences between patient groups. In conclusion, both the CFS- and the FM-group differed from the control group. Larger postural sway and insufficient control was found in patients compared to controls, with no significant differences between the two patient groups.

Patients with spondyloarthritis are equally satisfied with follow-up by physiotherapist and rheumatologist.

OBJECTIVE: International guidelines recommend that patients with spondyloarthritis (SpA) have lifelong physiotherapy, as physical activity and exercise are essential for optimizing health throughout the course of the disease. The aim of the present study was to investigate if a physiotherapy-led outpatient clinic specializing in SpA could provide satisfactory follow-up as an alternative to standard visits with a rheumatologist (RT). We hypothesized that satisfaction would be similar in patients followed by a physiotherapist (PT) or an RT. METHODS: A total of 68 patients were randomized to follow-up every fourth month by a PT or RT, for three visits in total. Patient satisfaction was evaluated using the Leeds Satisfaction Questionnaire (LSQ). Function, mobility and disease activity were rated using the Bath Ankylosing Spondylitis Functional Index (BASFI), Mobility Index (BASMI) and Ankylosing Spondylitis Disease Activity Score (ASDAS). RESULTS: Patients were equally satisfied with PT and RT follow-up at the first (p = 0.062) and last (p = 0.710) visit. At the second visit, the RT group was seen by a nurse, and was more satisfied than the PT group (p = 0.015). Function deteriorated in both the PT (p = 0.014) and RT (p = 0.007) groups. Mobility increased in the PT group (p = 0.020). Disease activity was not affected. CONCLUSIONS: Patients seem to be equally satisfied with either of the follow-up regimes. The PT-led follow-up did not seem to affect the patients' course of disease negatively. The results indicate that it would be safe to implement a PT-led clinic for patients with SpA in specialist health services, but longer-term follow-up is necessary to support the findings of this study.

Gross and fine motor function in fibromyalgia and chronic fatigue syndrome.

PURPOSE: This paper aimed to investigate motor proficiency in fine and gross motor function, with a focus on reaction time (RT) and movement skill, in patients with fibromyalgia (FM) and chronic fatigue syndrome (CFS) compared to healthy controls (HC). METHODS: A total of 60 individuals (20 CFS, 20 FM, and 20 HC), age 19-49 years, participated in this study. Gross motor function in the lower extremity was assessed using a RT task during gait initiation in response to an auditory trigger. Fine motor function in the upper extremity was measured during a precision task (the Purdue Pegboard test) where the number of pins inserted within 30 s was counted. RESULTS: No significant differences were found between FM and CFS in any parameters. FM and CFS groups had significantly longer RT than HC in the gait initiation (p=0.001, and p=0.004 respectively). In the Purdue Pegboard test, 20% in the FM group, 15% in the CFS groups, and 0% of HC group, scored below the threshold of the accepted performance. However, there were no significant differences between FM, CFS, and HC in this task (p=0.12). CONCLUSION: Compared to controls, both CFS and FM groups displayed significantly longer RT in the gait initiation task. Generally, FM patients showed the worst results in both tests, although no group differences were found in fine motor control, according to the Purdue Pegboard test.

TauG-guidance of dynamic balance control during gait initiation in patients with chronic fatigue syndrome and fibromyalgia.

BACKGROUND: Impaired postural control has been reported in static conditions in chronic fatigue syndrome and fibromyalgia, but postural control in dynamic tasks have not yet been investigated. Thus, we investigated measurements from a force plate to evaluate dynamic balance control during gait initiation in patients with chronic fatigue syndrome and fibromyalgia compared to matched healthy controls. METHODS: Thirty female participants (10 per group) performed five trials of gait initiation. Center of pressure (CoP) trajectory of the initial weight shift onto the supporting foot in the mediolateral direction (CoPX) was analyzed using General Tau Theory. We investigated the hypothesis that tau of the CoPX motion-gap (τCoPx) is coupled onto an intrinsic tauG-guide (τG) by keeping the relation τCoPx=KτG, where K is a scaling factor that determines the relevant kinematics of a movement. FINDINGS: Mean K values were 0.57, 0.55, and 0.50 in fibromyalgia, chronic fatigue syndrome, and healthy controls, respectively. Both patient groups showed K values significantly higher than 0.50 (P<0.05), indicating that patients showed poorer dynamic balance control, CoPX colliding with the boundaries of the base of support (K>0.5). INTERPRETATION: The findings revealed a lower level of dynamic postural control in both fibromyalgia and chronic fatigue syndrome compared to controls.

Altered postural control strategies in quiet standing more than 20 years after rupture of the anterior cruciate ligament.

AIM: To explore long-term consequences of anterior cruciate ligament (ACL) rupture on postural sway and control strategies during bilateral quiet standing, in subjects treated with or without reconstructive surgery compared to uninjured controls. METHOD: 70 individuals who had unilateral ACL rupture 23±2.4 years ago (33 received ACL reconstructive surgery, ACLR, and 37 had physiotherapy only, ACLPT) and 33 uninjured matched controls (CTRL) (mean age 46±5.3) stood quietly with eyes closed for 3min on a firm and on a compliant surface, respectively. Center of pressure (CoP) was registered with a force plate and postural sway was calculated from center of mass (CoM) derived from 3D kinematics. Sway density (SD) analyses of CoP assessed distance and duration of stable phases. The torque controlling postural sway was estimated from CoP-CoM. RESULTS: Comparisons across conditions to CTRL revealed larger CoP-CoM-area in ACLR (p=0.017, CI: 10.95, 143.10), but not in ACLPT. Mean distance between SD-peaks was greater for ACLR (p<0.001, CI: 1.73, 5.31) than for ACLPT (p=0.006, CI: 0.56, 4.12) relative to CTRL. Duration of SD-peaks was smaller for both ACLR and ACLPT (p<0.001, CI: -4.04, -1.23 and -3.82, -1.03, respectively) compared to CTRL. CoM-area in the ACL-groups did not differ from CTRL. CONCLUSIONS: ACL-injured subjects demonstrated greater postural control efforts than CTRL but without significant differences in postural sway. Control efforts were thus not directly associated with sway and further research should be focused on variance in postural control strategies.

Mechanisms controlling human head stabilization during random rotational perturbations in the horizontal plane revisited.

This study repeats the experimental protocol for investigation of head stabilization in healthy humans, described by Keshner and Peterson (1995) but with a modification of the analysis. Head movements were considered with respect to the room instead of relative to the trunk. The aim was to investigate the approximate contribution of reflex and voluntary control across perturbing frequencies and conditions with modulation of visual information and mental attention and discuss the resulting outcome while comparing methods. Seventeen healthy individuals were asked to keep the head steady in space while subjected to pseudorandom rotational perturbations in the horizontal plane, firmly seated on an actuated chair. Both methods confirmed the results for gain in previous studies showing fair ability to keep the head steady in space below 1 Hz with vision. Compensation deteriorated when vision was removed and worsened further with addition of a mental task. Between 1 and 2 Hz, unity gain occurred between head and trunk movements, whereas above 2 Hz the head moved more than the trunk. For phase angles, the original method demonstrated a phase split occurring from ~1 Hz, a purely mathematical artifact that caused subjects with virtually identical movements to appear as significantly different. This artifact was eliminated by analyzing the head-room relative to trunk-room rather than head-trunk relative to trunk-room angles, thus preventing potentially erroneous interpretations of the results.

Neck motion, motor control, pain and disability: A longitudinal study of associations in neck pain patients in physiotherapy treatment.

BACKGROUND: Neck pain is associated with several alterations in neck motion and motor control, but most of the findings are based on cross-sectional studies. OBJECTIVE: The aim of this study was to investigate associations between changes in neck motion and motor control, and changes in neck pain and disability in physiotherapy patients during a course of treatment. DESIGN: Prospective cohort study. METHOD: Subjects with non-specific neck pain (n = 71) participated in this study. Neck flexibility, joint position error (JPE), head steadiness, trajectory movement control and postural sway were recorded before commencement of physiotherapy (baseline), at 2 weeks, and at 2 months. Numerical Rating Scale and Neck Disability Index were used to measure neck pain and disability at the day of testing. To analyze within subjects effects in neck motion and motor control, neck pain, and disability over time we used fixed effects linear regression analysis. RESULTS: Changes in neck motion and motor control occurred primarily within 2 weeks. Reduction in neck pain was associated with increased cervical range of motion in flexion-/extension and increased postural sway when standing with eyes open. Decreased neck disability was associated with some variables for neck flexibility and trajectory movement control. Cervical range of motion in flexion-/extension was the only variable associated with changes in both neck pain and neck disability. CONCLUSIONS: This study shows that few of the variables for neck motion and motor control were associated with changes neck pain and disability over a course of 2 months with physiotherapy treatment.

Walking on a compliant surface does not enhance kinematic gait asymmetries after unilateral total knee arthroplasty.

PURPOSE: To investigate gait asymmetries and the effect of walking on compliant surfaces in individuals with unilateral total knee arthroplasty (TKA), hypothesizing that asymmetries would increase as an effect of the compliant surface. METHODS: Individuals with unilateral TKA ~19 months post-operative (n = 23, median age 59 years) recruited from one orthopaedic clinic and age- and gender-matched healthy individuals without knee complaints (n = 23, median age 56 years) walked at comfortable speed on a hard surface and on a compliant surface. 3D kinematic analyses were made for knee and hip angles in sagittal and frontal planes, stance time, step length, and gait velocity. RESULTS: Shorter stance time (p < 0.01) and less peak knee flexion (p < 0.001) at weight bearing acceptance was found in the prosthetic side compared with the contralateral side. Larger knee (p < 0.01) and hip (p < 0.001) adduction was found compared with healthy controls. Neither asymmetries between the prosthetic and the contralateral side nor differences compared with healthy controls were enhanced when walking on compliant surfaces compared with hard surfaces. CONCLUSION: The TKA group adapted their gait to compliant surfaces similarly to healthy controls. Gait asymmetries in the TKA group observed on hard surface were not enhanced, and adduction in hip and knee joints did not increase further as an effect of walking on compliant surfaces. Thus, unfavourable knee joint loading did not increase when walking on a compliant surface. This implies that recommendations for walking on soft surfaces to reduce knee joint loading are not counteracted by increased gait asymmetries and unfavourable joint loading configurations. LEVEL OF EVIDENCE: III.

Evidence for a general stiffening motor control pattern in neck pain: a cross sectional study.

BACKGROUND: Neck pain is associated with several alterations in neck motion and motor control. Previous studies have investigated single constructs of neck motor control, while few have applied a comprehensive set of tests to investigate cervical motor control. This comparative cross- sectional study aimed to investigate different motor control constructs in neck pain patients and healthy controls. METHODS: A total of 166 subjects participated in the study, 91 healthy controls (HC) and 75 neck pain patients (NP) with long-lasting moderate to severe neck pain. Neck flexibility, proprioception, head steadiness, trajectory movement control, and postural sway were assessed using a 3D motion tracking system (Liberty). The different constructs of neck motion and motor control were based on tests used in previous studies. RESULTS: Neck flexibility was lower in NP compared to HC, indicated by reduced cervical ROM and conjunct motion. Movement velocity was slower in NP compared to HC. Tests of head steadiness showed a stiffer movement pattern in NP compared to HC, indicated by lower head angular velocity. NP patients departed less from a predictable trajectory movement pattern (figure of eight) compared to healthy controls, but there was no difference for unpredictable movement patterns (the Fly test). No differences were found for postural sway in standing with eyes open and eyes closed. However, NP patients had significantly larger postural sway when standing on a balance pad. Proprioception did not differ between the groups. Largest effect sizes (ES) were found for neck flexibility (ES range: 0.2-0.8) and head steadiness (ES range: 1.3-2.0). Neck flexibility was the only construct that showed a significant association with current neck pain, while peak velocity was the only variable that showed a significant association with kinesiophobia. CONCLUSIONS: NP patients showed an overall stiffer and more rigid neck motor control pattern compared to HC, indicated by lower neck flexibility, slower movement velocity, increased head steadiness and more rigid trajectory head motion patterns. Only neck flexibility showed a significant association with clinical features in NP patients.