Differences in spinal posture and mobility between adults with obesity and normal weight individuals.

The aim of this study was to cross-sectionally investigate the relationships between obesity and spinal posture as well as mobility by comparing the spinal parameters between adults with obesity and normal-weight individuals. The spinal parameters were measured in 71 adults with obesity and 142 normal-weight individuals using a radiation-free back scan, the Idiag M360. Differences in spinal posture and movements between the two groups were determined using a two-way analysis of variance. Adults with obesity had greater thoracic kyphosis [difference between groups (Δ) = 6.1°, 95% CI 3.3°-8.9°, p < 0.0001] and thoracic lateral flexion (Δ = 14.5°, 95% CI 5.1°-23.8°, p = 0.002), as well as smaller thoracic flexion (Δ = 3.5°, 95% CI 0.2°-6.9°, p = 0.03), thoracic extension (Δ = 4.1°, 95% CI 1.1°-7.1°, p = 0.008), lumbar flexion (Δ = 10.4°, 95% CI 7.7°-13.5°, p < 0.0001), lumbar extension (Δ = 4.8°, 95% CI 2.2°-7.4°, p = 0.0003) and lumbar lateral flexion (Δ = 12.8°, 95% CI 9.8°-15.7°, p = < 0.0001) compared to those with normal weight. These findings provide relevant information about the characteristics of the spine in adults with obesity to be taken into careful consideration in the prescription of adapted physical activities within integrated multidisciplinary pathways of metabolic rehabilitation.

Powered hip exoskeleton improves walking economy in individuals with above-knee amputation.

Above-knee amputation severely reduces the mobility and quality of life of millions of individuals. Walking with available leg prostheses is highly inefficient, and poor walking economy is a major problem limiting mobility. Here we show that an autonomous powered hip exoskeleton assisting the residual limb significantly improves metabolic walking economy by 15.6 ± 2.9% (mean ± s.e.m.; two-tailed paired t-test, P = 0.002) in six individuals with above-knee amputation walking on a treadmill. The observed metabolic cost improvement is equivalent to removing a 12-kg backpack from a nonamputee individual. All participants were able to walk overground with the exoskeleton, including starting and stopping, without notable changes in gait balance or stability. This study shows that assistance of the user's residual limb with a powered hip exoskeleton is a viable solution for improving amputee walking economy. By significantly reducing the metabolic cost of walking, the proposed hip exoskeleton may have a considerable positive impact on mobility, improving the quality of life of individuals with above-knee amputations.

Clinical Assessment and Treatment Options for Posterior Hip Pain.

BACKGROUND: Diagnosis and treatment of posterior hip pain has increased due to advancements in clinical, anatomical, biomechanical, and related pathological understandings of the hip. Due to its complexity and close anatomical relationship with many osseous, neurovascular, and musculotendinous structures, posterior hip pain must be appropriately categorized based on its origin. Therefore, it is crucial that clinicians are able to determine whether patient complaints are of extra-articular or intra-articular nature so that they can implement the optimal treatment plan. In the current review article, we discussed posterior hip pain with an emphasis on the main differential diagnoses of deep gluteal syndrome, ischiofemoral impingement, and hamstring tear/hamstring syndrome. For the appropriate diagnosis and etiology of posterior hip pain, a thorough and conclusive clinical history is imperative. Physicians should rule out the possibility of spinal involvement by physical examination and if necessary, by magnetic resonance imaging (MRI). Furthermore, because of the vicinity to other, non-orthopedic structures, an obstetric and gynecologic history, general surgery history, and urologic history should be obtained. Following the collection of patient history clinicians should adhere to an established and efficient order of evaluation starting with standing then to seated, supine, lateral, and prone testing. Imaging assessment of posterior hip pain begins with a standard anterior-posterior pelvic radiograph, in addition to frog-leg lateral. MRI is pivotal for assessing soft tissue-related extra-articular causes of hip in patients with posterior hip pain. Non-surgical treatment is preferred in most cases of deep gluteal syndrome, ischiofemoral impingement, pudendal nerve entrapment, and proximal hamstring pathologies. Surgical treatment is saved as a last resort option in cases of failed non-surgical treatment.

Clinical Hip Osteoarthritis in Current and Former Professional Footballers and Its Effect on Hip Function and Quality of Life.

The objective of the study was to establish the prevalence of clinical hip osteoarthritis in current and former professional footballers and to explore its consequences on hip function and health-related quality of life (HRQoL). A cross-sectional study by means of questionnaire was conducted among current and former professional footballers fulfilling the following inclusion criteria: (1) male (2) active or retired professional footballer (3) member of FIFPRO (Football Players Worldwide) (4) between 18 and 50 years old (5) could read and understand texts in French, Spanish, or English. Controls (matched for: gender, age, body weight and height) were also recruited. The main outcome measures were clinical hip osteoarthritis, hip function and HRQoL. Questionnaires were sent to 2,500 members of which 1,401 participated (1,000 current and 401 former professional footballers). Fifty-two controls were recruited. Prevalence of hip osteoarthritis was 2% among current and 8% among former professional footballers. Hip function was significantly (p ≤ 0.001) lower in both types of footballers with hip osteoarthritis than in footballers without hip osteoarthritis and controls. Current and former professional footballers with hip osteoarthritis reported significantly lower physical health scores (p = 0.032, p = 0.002) than those without. Hip osteoarthritis led to a significantly lower score in the physical (p = 0.004) and mental (p = 0.014) component of HRQoL in former footballers compared to the controls, while in current footballers only the physical component was significantly (p = 0.012) lower compared to the controls. Hip osteoarthritis has a higher prevalence in former than in current professional footballers and impacts hip function and HRQoL negatively.

Maximal hip muscle strength and rate of torque development 6-30 months after hip arthroscopy for femoroacetabular impingement syndrome: A cross-sectional study.

OBJECTIVES: Reduced sports function is often observed after hip arthroscopy for femoroacetabular impingement syndrome (FAIS). Impaired muscle strength could be reasons for this. We aimed to investigate hip muscle strength after hip arthroscopy for FAIS and its association with sports function and participation. DESIGN: Cross-sectional study. METHODS: We included 45 patients (34 males; mean age: 30.6 ±â€¯5.9 years) after unilateral hip arthroscopy for FAIS (mean follow-up [range]: 19.3 [9.8-28.4] months). Maximal isometric hip muscle strength (Nm/kg) including early- (0-100 ms) and late-phase (0-200 ms) rate of torque development (Nm∗kg-1∗s-1) for adduction, abduction, flexion, and extension was measured with an externally fixated handheld dynamometer and compared between operated and non-operated hip. Associations between muscle strength and self-reported sports function and return to sport were investigated. RESULTS: For maximal hip muscle strength, no between-hip differences were observed for adduction, abduction, flexion, and extension (p ≥ 0.102). For rate of torque development, significantly lower values were observed for the operated hip in flexion at both 0-100 ms (mean difference: 1.58 Nm∗kg-1∗s-1, 95% CI [0.39; 2.77], p = 0.01) and 0-200 ms (mean difference: 0.72 Nm∗kg-1∗s-1, 95% CI [0.09; 1.35], p = 0.027). Higher maximal hip extension strength was significantly associated with greater ability to participate fully in preinjury sport at preinjury level (odds ratio: 17.71 95% CI [1.77; 177.60]). CONCLUSIONS: After hip arthroscopy for FAIS subjects show limited impairments in maximal and explosive hip muscle strength between operated and non-operated hip. Higher muscle strength was positively associated with higher sports function and ability to participate in sport.

Immediate Improvements in Patellofemoral Pain Are Associated With Sagittal Plane Movement Training to Improve Use of Gluteus Maximus Muscle During Single Limb Landing.

OBJECTIVE: The authors sought to examine the immediate effects of movement training aimed at improving use of gluteus maximus (GMAX) in the sagittal plane on hip internal rotation and self-reported patellofemoral pain (PFP) during single-limb landing. METHODS: Seventeen females with PFP participated. Lower extremity kinematics and kinetics, GMAX activation, and self-reported PFP were obtained before and after a single-session movement training program aimed at increasing the use of GMAX. Dependent variables of interest included self-reported PFP, average GMAX activation, average hip extensor moment, and peak hip internal rotation. Post-training changes were evaluated using paired t tests and Wilcoxon signed rank tests. RESULTS: Following movement training, self-reported PFP decreased significantly (mean [standard deviation]) (3.9 [1.1] vs 0.8 [1.3] on a 0-10 scale). Additionally, significant increases were observed for the average hip extensor moment (0.6 [0.3] vs 1.8 [0.4] Nm/kg) and average GMAX activation (41.0% [18.3] vs 51.6% [25.7] maximum voluntary isometric contraction), whereas peak hip internal rotation decreased significantly (8.5 degrees [5.8] vs 6.0 degrees [5.3]). CONCLUSION: Movement training aimed at improving the use of GMAX in the sagittal plane resulted in clinically relevant changes in self-reported pain, GMAX activation, and hip kinetics and kinematics. Improving the use of GMAX during movement merits consideration when designing rehabilitation programs for females with PFP. IMPACT: The current study highlights the clinical utility of movement training for persons with PFP and provides a biomechanical rationale for its use as a potential intervention in this population.

Hip Strength Before and After Arthroscopic Femoroacetabular Impingement Surgery.

Femoroacetabular impingement (FAI) and labral pathology are associated with pain, decreased function, and hip strength deficits. Existing data are in conflict regarding when hip strength normalizes following arthroscopic treatment of FAI. The objective of this study was to identify preoperative hip strength relative to the contralateral hip not undergoing surgery as well as when postoperative strength in 4 functional muscle groups normalizes following arthroscopic treatment of FAI. Ninety-eight individuals with radiographic evidence of FAI and labral pathology underwent arthroscopic labral repair. Pre-surgical hip strength testing was performed in the symptomatic "surgical hip" and the contralateral "non-surgical hip." Hip strength measurements were repeated at 8 and 16 weeks postoperatively. Significant preoperative hip strength deficits were noted in the surgical hip compared with the non-surgical hip in flexion, extension, and adduction. At 8 weeks postoperatively, hip strength in the surgical hip improved to being equivalent to that in the non-surgical hip in adduction and extension, remained equivalent to that of the non-surgical hip in abduction, and decreased in flexion relative to the non-surgical hip. At 16 weeks, hip strength remained equivalent in the surgical hip and the non-surgical hip in abduction and adduction, but the surgical hip exceeded the non-surgical hip in extension. While flexion strength improved between 8 and 16 weeks postoperatively for the surgical hip, it had not fully recovered to that of the non-surgical hip. Using a structured postoperative rehabilitation protocol, abduction strength was maintained at 8 weeks postoperatively, while adduction and extension strength had improved to those of the non-surgical hip. At 16 weeks postoperatively, hip abduction and adduction had strength equivalent to those of the non-surgical hip. Despite preoperative improvement, flexion of the surgical hip lagged behind that of the non-surgical hip 16 weeks postoperatively. [Orthopedics. 2021;44(3):148-153.].

Differences in lower-extremity kinematics between the male military personnel with and without plantar fasciitis.

OBJECTIVE: To evaluate the factors that influence gait by comparing lower extremity kinematics during the stance phase of the gait cycle between individuals with and without plantar fasciitis. DESIGN: A cross-sectional study. SETTING: Motion analysis research laboratory. PARTICIPANTS: Thirty subjects with plantar fasciitis and 30 aged-matched controls. MAIN OUTCOME MEASURE(S): Range of motion of the lower extremity and multi-segment foot during gait using a three-dimensional motion analysis system. RESULTS: The plantar fasciitis group showed significant differences in motion in the multi-segment foot, ankle, knee, and hip from the control group during various subphases of the stance phase. Specifically, relative to the control group, the plantar fasciitis group had more rearfoot adduction, forefoot eversion, ankle abduction, and hip abduction. They also had less midfoot dorsiflexion, forefoot dorsiflexion, knee extension, knee external rotation, and hip extension (all Ps < 0.05). CONCLUSIONS: Individuals with plantar fasciitis exhibited more flexibility in the ankle-foot complex and poorer quality of lower-extremity movement than the group that did not have plantar fasciitis. Thus, differences in structures in both the ankle-foot complex as well as those in the hip and knee joints appear to be associated with the presence of plantar fasciitis.

Limb dominance influences energy absorption contribution (EAC) during landing after anterior cruciate ligament reconstruction.

OBJECTIVE: To determine the role of limb dominance on energy absorption contribution (EAC) during a jump landing (JL) task at return to sport (RTS) after ACL-R. DESIGN: Cross-sectional study. SETTING: Clinical Research Laboratory. PARTICIPANTS: One hundred eight participants (age = 16.19 ± 1.74, Height = 172.25 ± 9.96 cm, Weight = 72.61 ± 15.48 kg). MAIN OUTCOME MEASURES: Participants were grouped into two groups: those who injured their dominant limb ACL (D-ACL) and those who injured their non-dominant limb ACL (ND-ACL). A multiple analysis of variance (MANOVA) was used to assess for between group differences in EAC across the three joints. RESULTS: In the surgical limb, D-ACL demonstrated smaller hip (D-ACL = 32.23 ± 10.44%, ND-ACL = 69.68 ± 8.51%, p < 0.008) and greater knee (D-ACL = 45.86 ± 10.36%, ND-ACL = 9.41 ± 5.68%, p < 0.008) EAC than ND-ACL. In the non-surgical limb, D-ACL demonstrated greater hip (D-ACL = 62.59 ± 9.03%, ND-ACL = 25.95 ± 7.15%, p < 0.008), and smaller knee (D-ACL = 13.79 ± 5.57%, ND-ACL = 58.01 ± 7.86%, p < 0.008), EAC than ND-ACL. CONCLUSION: After ACL-R, eccentric loading strategies during a JL task at RTS are different depending upon limb dominance. D-ACL demonstrated a greater knee loading strategy on the surgical side compared to ND-ACL.

Anteromedial versus posterolateral hip musculature strengthening with dose-controlled in women with patellofemoral pain: A randomized controlled trial.

OBJECTIVE: To compare the effectiveness of adding anteromedial versus posterolateral hip musculature strengthening to knee strengthening in women with patellofemoral pain (PFP). DESIGN: Randomized controlled trial. SETTING: University physiotherapy clinic. PARTICIPANTS: Fifty-two women with PFP were randomized to receive either anteromedial (AMHG) or posterolateral (PLHG) hip musculature strengthening. MAIN OUTCOME MEASURES: The primary outcomes were pain intensity by the numeric pain rating scale and function by the Anterior Knee Pain Scale in six weeks. Secondary outcomes were pain and function at six months, global perceived effect at six weeks and six months, pain in step down, isometric torque of abductors, adductors and hip rotators measured with hand-held dynamometer, and dynamic knee valgus by step down in six weeks. RESULTS: Both groups showed improvement in primary outcomes; however, no differences were found between groups in pain intensity and function in six weeks and the secondary outcomes. Group x time interaction found superior gains in abductor strength in the PLHG and increase in the strength of the adductors and internal rotators in AMHG. CONCLUSION: There was no difference between the addition of anteromedial or posterolateral hip musculature strengthening to knee strengthening in improving pain and function in women with PFP.

Does Patient-specific Functional Pelvic Tilt Affect Joint Contact Pressure in Hip Dysplasia? A Finite-element Analysis Study.

BACKGROUND: Although individual and postural variations in the physiologic pelvic tilt affect the acetabular orientation and coverage in patients with hip dysplasia, their effect on the mechanical environment in the hip has not been fully understood. Individual-specific, finite-element analyses that account for physiologic pelvic tilt may provide valuable insight into the contact mechanics of dysplastic hips, which can lead to further understanding of the pathogenesis and improved treatment of this patient population. QUESTION/PURPOSE: We used finite-element analysis to ask whether there are differences between patients with hip dysplasia and patients without dysplasia in terms of (1) physiologic pelvic tilt, (2) the pelvic position and joint contact pressure, and (3) the morphologic factors associated with joint contact pressure. METHODS: Between 2016 and 2019, 82 patients underwent pelvic osteotomy to treat hip dysplasia. Seventy patients with hip dysplasia (lateral center-edge angle ≥ 0° and < 20° on supine AP pelvic radiographs) were included. Patients with advanced osteoarthritis, femoral head deformity, prior hip or supine surgery, or poor-quality imaging were excluded. Thirty-two patients (32 hips) were eligible to this finite-element analysis study. For control groups, we reviewed 33 female volunteers without a history of hip disease. Individuals with frank or borderline hip dysplasia (lateral center-edge angle < 25°) or poor-quality imaging were excluded. Sixteen individuals (16 hips) were eligible as controls. Two board-certified orthopaedic surgeons measured sagittal pelvic tilt (the angle between the anterior pelvic plane and vertical axis: anterior pelvic plane [APP] angle) and acetabular version and coverage using pelvic radiographs and CT images. Intra- and interobserver reliabilities, evaluated using the kappa value and intraclass correlation coefficient, were good or excellent. We developed individual-specific, finite-element models using pelvic CT images, and performed nonlinear contact analysis to calculate the joint contact pressure on the acetabular cartilage during the single-leg stance with respect to three pelvic positions: standardized (anterior pelvic plane), supine, and standing. We compared physiologic pelvic tilt between patients with and without dysplasia using a t-test or the Wilcoxon rank sum test. A paired t-test or the Wilcoxon signed rank test with a Bonferroni correction was used to compare joint contact pressure between the three pelvic positions. We correlated joint contact pressure with morphologic parameters and pelvic tilt using the Pearson or the Spearman correlation coefficients. RESULTS: The APP angle in the supine and standing positions varied widely among individuals. It was greater in patients with hip dysplasia than in patients in the control group when in the standing position (3° ± 6° versus -2° ± 8°; mean difference 5° [95% CI 1° to 9°]; p = 0.02) but did not differ between the two groups when supine (8° ± 5° versus 5° ± 7°; mean difference 3° [95% CI 0° to 7°]; p = 0.06). The mean pelvic tilt was 6° ± 5° posteriorly when shifting from the supine to the standing position in patients with hip dysplasia. The median (range) maximum contact pressure was higher in dysplastic hips than in control individuals (in standing position; 7.3 megapascals [MPa] [4.1 to 14] versus 3.5 MPa [2.2 to 4.4]; difference of medians 3.8 MPa; p < 0.001). The median maximum contact pressure in the standing pelvic position was greater than that in the supine position in patients with hip dysplasia (7.3 MPa [4.1to 14] versus 5.8 MPa [3.5 to 12]; difference of medians 1.5 MPa; p < 0.001). Although the median maximum joint contact pressure in the standardized pelvic position did not differ from that in the standing position (7.4 MPa [4.3 to 15] versus 7.3 MPa [4.1 to 14]; difference of medians -0.1 MPa; p > 0.99), the difference in the maximum contact pressure varied from -3.3 MPa to 2.9 MPa, reflecting the wide range of APP angles (mean 3° ± 6° [-11° to 14°]) when standing. The maximum joint contact pressure in the standing position was negatively correlated with the standing APP angle (r = -0.46; p = 0.008) in patients with hip dysplasia. CONCLUSION: Based on our findings that individual and postural variations in the physiologic pelvic tilt affect joint contact pressure in the hip, future studies on the pathogenesis of hip dysplasia and joint preservation surgery should not only include the supine or standard pelvic position, but also they need to incorporate the effect of the patient-specific pelvic tilt in the standing position on the biomechanical environment of the hip. CLINICAL RELEVANCE: We recommend assessing postural change in sagittal pelvic tilt when diagnosing hip dysplasia and planning preservation hip surgery because assessment in a supine or standard pelvic position may overlook alterations in the hip's contact mechanics in the weightbearing positions. Further studies are needed to elucidate the effect of patient-specific functional pelvic tilt on the degeneration process of dysplastic hips, the acetabular reorientation maneuver, and the clinical result of joint preservation surgery.

Hip and knee muscle torque and its relationship with dynamic balance in chronic ankle instability, copers and controls.

OBJECTIVES: We compared hip and knee isometric muscle torque between individuals with chronic ankle instability (CAI), those who have sustained one ankle sprain with no ongoing problems (copers) and healthy controls. Our secondary objective was to compare balance between groups and investigate the relationship between muscle torque and balance. DESIGN: Cross-sectional study. METHODS: 22 CAI, 20 copers and 22 uninjured participants were tested. Isometric torque (normalised to body mass (Nm/kg)) was measured using a rigidly-fixated hand-held dynamometer. Balance was assessed with the Y-balance test. RESULTS: Knee and hip flexor and extensor, and hip adductor and abductor muscle torque was less in individuals with CAI compared to controls (standardised mean difference (SMD) >1.2). Hip and knee flexor and extensor muscle torque was less in CAI participants than copers (SMD: 0.69-1.1). Hip external and internal rotator torque did not differ between groups. There was no difference in hip or knee muscle torque between controls and copers (SMD: 0.01-0. 54). Balance was impaired in CAI participants compared to copers and controls in all directions. There was a strong positive correlation between posterolateral Y-balance test performance and torque of the hip adductors (r=0.53), flexors (r=0.52) and extensors (r=0.50). CONCLUSIONS: Individuals with CAI have weak knee and hip muscles compared to copers and controls. Hip strength was shown to be related to posterolateral balance performance. Future studies may investigate the effect of hip and knee strengthening exercise on ongoing ankle problems, such as episodic giving way in individuals with CAI.

Influence of symptom frequency and severity on hip abductor strength and endurance in individuals with patellofemoral pain.

OBJECTIVE: To compare clinical measures of hip abductor strength and endurance of individuals with patellofemoral pain with more severe symptoms to those with less severe symptoms. DESIGN: Cross-sectional. SETTINGS: Laboratory. PARTICIPANTS: Sixty participants with patellofemoral pain were divided three times into 2 groups according to three symptomatology criteria: functional capacity, pain frequency and pain severity. MAIN OUTCOME MEASURES: Isometric strength evaluated using a hand-held dynamometer, endurance using maximum number of repetitions and maximum holding time, functional capacity using the Anterior Knee Pain Scale, pain frequency using a 2-category scale ("Less frequent" = 1-2 times a week; "More frequent" = >3 times a week) and pain severity using Numeric Pain Rating Scales. RESULTS: Participants with more frequent symptoms and with more severe pain were significantly weaker (10%, p = 0.04 and 16%, p = 0.001, respectively), and had less isometric (17%, p = 0.02 and 24%, p = 0.002, respectively) and dynamic (13%, p = 0.02 and 23%, p = 0.007, respectively) endurance compared to those with less pronounced symptoms. CONCLUSION: Our study highlighted that hip abductor strength and endurance deficits are more pronounced in individuals with more severe and frequent pain.

Short Walking Exercise Leads to Gait Changes and Muscle Fatigue in Children With Cerebral Palsy Who Walk With Jump Gait.

OBJECTIVE: The aim of this study was to evaluate kinematic changes and muscle fatigue in jump gait during a walking exercise and the relationship between kinematic changes and muscle fatigue and strength. DESIGN: This preliminary study included 10 children with cerebral palsy who walk with jump gait. Hip and knee maximal isometric muscle strength were measured using a dynamometer. Then, lower-limb kinematics and electromyography were collected while children walked continuously for 6 min at their self-selected speed. Electromyography median frequency and lower-limb joint angles were compared between the first and the sixth minutes of the walking exercise using t test and Wilcoxon rank test. The relationship between kinematic changes and muscle strength and changes in electromyography median frequency were assessed using correlation analyses. RESULTS: During stance, maximal knee flexion significantly increased at the sixth minute (P = 0.01) and was associated with knee extensor muscle weakness (ρ = -0.504, P = 0.03). Muscle fatigue was observed only in the gluteus medius muscle (P = 0.01). CONCLUSIONS: Children with cerebral palsy who walked with jump gait and who had knee extensor weakness were more prone to an increase in knee flexion during a continuous walk. The fatigue in the gluteus medius muscle suggests that physical intervention should target the endurance of this muscle to improve jump gait.

Walking energetics and abductor strength are associated with physical activity in older women with hip osteoarthritis.

BACKGROUND: Osteoarthritis (OA) can hinder physical activity in older adults for reasons that are not fully understood. Functional barriers may exist such as reduced muscle strength around the affected joint, potentially affecting physical activity. Aging-associated declines in energy capacity may also be exacerbated by OA. These factors may work together to influence physical activity in people with OA. RESEARCH QUESTION: Our objective was to evaluate the combined role of walking energetics and hip abductor strength on physical activity in older women with hip OA. METHODS: We evaluated 30 women with moderately symptomatic hip OA (61 ± 10 yrs; 30.7 ± 4.9 kg/m2) in this cross-sectional observational study. We measured physical activity using the UCLA activity score and quantified activity frequency and intensity using accelerometers worn for seven days (7 ± 2 days). We used a portable oxygen exchange system to measure energy used during walking at preferred speeds (relative to total energy capacity assessed using a six-minute walk test) and a dynamometer to measure hip abductor strength. We used Pearson correlations and regression analysis to test our hypotheses. RESULTS: Greater energy used during walking was associated with lower self-reported physical activity (R=-0.626, p < 0.001), more sedentary time (R = 0.567, p = 0.002), and less light activity time (R=-0.644, p < 0.001). Lower hip abductor strength was associated with lower self-reported physical activity (R = 0.406, p = 0.039). While there was no association between hip abductor strength and energy used during walking, together these variables predicted 55.5 % of the variance in self-reported physical activity. SIGNIFICANCE: Results suggest intervention targets to promote physical activity in this population.

Hip pain in adolescents with cerebral palsy: a population-based longitudinal study.

AIM: To investigate the prevalence, characteristics, and risk factors of hip pain in adolescents with cerebral palsy (CP) and compare the findings with those of the same individuals 5 years earlier. METHOD: Sixty-seven adolescents (28 females, 39 males; mean age 14y 7mo; SD 1y 5mo; range 12-17y) with bilateral CP, in Gross Motor Function Classification System (GMFCS) levels III to V enrolled in a CP surveillance programme were assessed for hip pain. Their caregivers responded to the questions on the intensity and frequency of hip pain from the Child Health Questionnaire (CHQ) (transformed to CHQ hip pain score; 100 indicates no pain). Interference of hip pain with daily activities and sleep was recorded on numeric rating scales. Hip displacement was measured radiographically by the migration percentage. RESULTS: Twenty-eight participants had 44 painful hips. Their mean CHQ hip pain score was 40 (SD 21.4; range 10-80). Independent risk factors for hip pain, low CHQ hip pain score, and interference with sleep were severe hip subluxation (migration percentage 50-89%) and GMFCS level V. A migration percentage of 50% to 89% was the only independent risk factor for interference with daily activities. Over 5 years, the number of participants with hip pain increased from 18 to 28, while the mean migration percentage of the most displaced hip was unchanged. INTERPRETATION: Our CP hip surveillance programme did not protect the participants against increasing prevalence of hip pain during adolescence. We suggest that surveillance programmes for CP should include guidelines on the characteristics and management of hip pain. WHAT THIS PAPER ADDS: Hip pain prevalence increased in adolescents over a 5-year period in a cerebral palsy surveillance programme. Risk factors for hip pain were Gross Motor Function Classification System level V and severe hip subluxation.

Evaluation of the bent knee fall out test pre- and post- an adductor longus tenotomy.

OBJECTIVE: To investigate the immediate effect of an adductor longus tenotomy on the results of the bent knee fall out test, and whether there was a correlation between pre-tenotomy measures and the magnitude of change. DESIGN: Observational study. METHODS: We included recreational to elite athletes with longstanding adductor-related groin pain (specifically adductor longus insertion pain) undergoing unilateral or bilateral full adductor longus tenotomy. The bent knee fall out test was performed immediately prior and immediately after the surgical procedure. We used Wilcoxon signed-rank test to compare test results pre- and post-tenotomy, and Spearman's rho (rs) to analyse correlation between pre-tenotomy values and the magnitude of change in the bent knee fall out test. RESULTS: We consecutively included 60 male adult athletes. There was a statistically significant difference (p < 0.001) in the bent knee fall out result from pre-surgery (median 11.5 cm [IQR 9-15], range 5-25 cm) to post-surgery (median 8 cm [IQR 6-10], range 3-15 cm). The mean difference was 3.9 ± 2 cm, range 0-11 cm, corresponding to a large effect size, d = 1.92. There was a moderate correlation between the bent knee fall out measurement pre-tenotomy and the difference from pre-to-post, rs = 0.75, p < 0.001. CONCLUSION: The bent knee fall out measurements changed considerably immediately after an adductor longus tenotomy, showing that the test is assessing adductor longus flexibility in male athletes with longstanding adductor-related groin pain. There was a moderate correlation between the bent knee fall out measure pre-tenotomy and the magnitude of change.

Juvenile idiopathic arthritis, gait characteristics and relation to function.

BACKGROUND: Juvenile Idiopathic Arthritis (JIA) is a chronic inflammatory arthritis that impacts biomechanical features of gait. This systematic review describes the effects of JIA on gait motion parameters and walking performance. METHODS: Six databases were searched (PubMed/Medline, Cochrane, the EBSCOHost database SPORTDiscus, Web of Science, and Embase). Studies were restricted to children with any subtype of JIA who were assessed for gait motion features (kinematic, kinetic, temporalspatial) or walking performance (velocity or distance covered); could include intervention or treatment exposure with measures of gait and gait speed; could involve comparison of gait in JIA to healthy controls. Quality of evidence was assessed using the GRADE system. This systematic review was registered at PROSPERO (CRD42018109582) RESULTS: The search yielded 625 papers, 23 of which described biomechanical features of gait and/or assessed walking performance. Twenty studies measured walking velocity and walking ability using simple field tests or laboratory methods. Eleven studies measured temporalspatial parameters such as cadence, step length, stride length, step width, single and double support time. Nine studies evaluated kinetic measurements including joint power, flexion and extension and joint moments. Nine studies evaluated kinematic parameters including range of motion, pelvic tilt, center of motion and trunk sway. CONCLUSIONS: Key features of gait in children with JIA include slower gait velocity, shortened step length, decreased range of motion at the hip, knee and ankle with trend towards flexion, decreased joint power, anteriorly tilted pelvis and trunk with shifted center of motion. There is a potential to ameliorate JIA-related gait changes with exercise and/or pharmaceutical interventions.

Effects of knee osteoarthritis severity on inter-joint coordination and gait variability as measured by hip-knee cyclograms.

Inter-joint coordination and gait variability in knee osteoarthritis (KOA) has not been well investigated. Hip-knee cyclograms can visualize the relationship between the hip and knee joint simultaneously. The aim of this study was to elucidate differences in inter-joint coordination and gait variability with respect to KOA severity using hip-knee cyclograms. Fifty participants with KOA (early KOA, n = 20; advanced KOA, n = 30) and 26 participants (≥ 50 years) without KOA were recruited. We analyzed inter-joint coordination by hip-knee cyclogram parameters including range of motion (RoM), center of mass (CoM), perimeter, and area. Gait variability was assessed by the coefficient of variance (CV) of hip-knee cyclogram parameters. Knee RoM was significantly reduced and total perimeter tended to be decreased with KOA progression. KOA patients (both early and advanced) had reduced stance phase perimeter, swing phase area, and total area than controls. Reduced knee CoM and swing phase perimeter were observed only in advanced KOA. Both KOA groups had a greater CV for CoM, knee RoM, perimeter (stance phase, swing phase and total) and swing phase area than the controls. Increased CV of hip RoM was only observed in advanced KOA. These results demonstrate that hip-knee cyclograms can provide insights into KOA patient gait.