Stiff-legged Gait Research Articles

Novel loss-of-function variants in WDR26 cause Skraban-Deardorff syndrome in two Chinese patients.

Mutations in the protein WD repeat structural domain 26 (WDR26, MIM 617424) have been identified as the cause of autosomal dominant Skraban-Deardorff syndrome, a rare genetic disorder characterized by intellectual disability (ID), developmental delay (DD), hypotonia, epilepsy, infant feeding difficulties, gait abnormalities and distinctive facial features. The objective of this study is to investigate the genetic factors that may contribute to the development of Skraban-Deardorff syndrome in affected individuals. In this study, we used whole-exome sequencing (WES) to analyze pathogenic and likely pathogenic variants in two unrelated Chinese patients with DD and ID. We confirmed the origin of the variants by conducting Sanger sequencing and classified them according to ACMG/AMP guidelines. Here, two novel de novo variants (c.1797delC(p.His599fs*11) and c.1414C>T(p.Gln472*)) in the WDR26 gene have been identified in two Chinese patients with Skraban-Deardorff syndrome. These patients exhibit a range of symptoms, including varying degrees of ID, DD, speech delay, an abnormal wide-foot and/or stiff-legged gait, facial dysmorphism, behavioural abnormalities, with or without seizures. In this study, We report two unrelated Chinese patients with Skraban-Deardorff syndrome caused by novel de novo pathogenic variants of the WDR26 gene. These patients showed a clinical phenotype similar to that of patients with the WDR26 variant. Compared to reported cases with WDR26 pathogenic variants, patient 2 presented a novel complication of severe behavioural problems, including hyperactivity, social anxiety, self-mutilation, impulsivity and violent behaviour. This research broadens the range of genetic and clinical features of Skraban-Deardorff syndrome. In addition, the symptoms may become more pronounced as the patient ages. Furthermore, our report highlights the clinical diversity of Skraban-Deardorff syndrome. The findings may assist healthcare professionals in providing more accurate genetic testing and counselling to affected families and improving the overall management of the condition.

Fourier Analysis of the Vertical Ground Reaction Force During Walking: Applications for Quantifying Differences in Gait Strategies.

Time series biomechanical data inform our understanding of normal gait mechanics and pathomechanics. This study examines the utility of different quantitative methods to distinguish vertical ground reaction forces (VGRFs) from experimentally distinct gait strategies. The goals of this study are to compare measures of VGRF data-using the shape factor method and a Fourier series-based analysis-to (1)describe how these methods reflect and distinguish gait patterns and (2)determine which Fourier series coefficients discriminate normal walking, with a relatively stiff-legged gait, from compliant walking, using deep knee flexion and limited vertical oscillation. This study includes a reanalysis of previously presented VGRF data. We applied the shape factor method and fit 3- to 8-term Fourier series to zero-padded VGRF data. We compared VGRF renderings using Euclidean L2 distances and correlations stratified by gait strategy. Euclidean L2 distances improved with additional harmonics, with limited improvement after the seventh term. Euclidean L2 distances were greater in shape factor versus Fourier series renderings. In the 8 harmonic model, amplitudes of 9 Fourier coefficients-which contribute to VGRF features including peak and local minimum amplitudes and limb loading rates-were different between normal and compliant walking. The results suggest that Fourier series-based methods distinguish between gait strategies.

Thigh and Shank, Kinetic and Potential Energies during Gait Swing Phase in Healthy Adults and Stroke Survivors.

Background/Problem. Given the treatment-resistant gait deficits after stroke and known elevated energy cost of gait after stroke, it is important to study the patterns of mechanical energies of the lower limb segments. There is a dearth of information regarding mechanical energies specifically for the thigh and shank across the gait cycle. Therefore, the purpose of the current work was to characterize the following: (1) relative patterns of oscillation kinetic energy (KE) and potential energy (PE) within lower limb segments and across lower limb segments in healthy adults during the swing phase at chosen and slow gait speeds; (2) KE and PE swing phase patterns and values for stroke survivors versus healthy adults walking at slow speed; and (3) KE and PE patterns during the swing phase for two different compensatory gait strategies after stroke,. Methods. This was a gait characterization study, a two-group, parallel-cohort study of fourteen stroke survivors with gait deficits, walking at <0.4 m/s and eight adults with no gait deficits. For testing, the eight healthy adults walked at their chosen speed, and then at the imposed slow speed of <0.04 m/s. We used a standard motion capture system and calculation methods to acquire, calculate, and characterize oscillation patterns of KE and PE of the limb segments (thigh and shank) across the gait cycle. Results. In healthy adults, we identified key energy conservation mechanisms inherent in the interactions of KE and PE, both within the thigh and shank segments and across those limb segments, partially explaining the low cost of energy of the normal adult chosen speed gait pattern, and the underlying mechanism affording the known minimal set of activated muscles during walking, especially during the early swing phase. In contrast, KE was effectively absent for both healthy adults at imposed slow walking speed and stroke survivors at their very slow chosen speed, eliminating the normal conservation of energy between KE and PE within the thigh and across the thigh and shank. Moreover, and in comparison to healthy adult slow speed, stroke survivors exhibited greater abnormalities in mechanical energies patterns, reflected in either a compensatory stepping strategy (over-flexing the hip) or circumducting strategy (stiff-legged gait, with knee extended throughout the swing phase). Conclusions and contribution to the field. Taken together, these findings support targeted training to restore normal balance control and normal activation and de-activation coordination of hip, knee, and ankle muscles, respectively (agonist/antagonist at each joint), so as to eliminate the known post-stroke abnormal co-contractions; this motor training is critical in order to release the limb to swing normally in response to mechanical energies and afford the use of conservation of KE and PE energies within the thigh and across thigh and shank.

Selenium in human and animal nutrition and need for selenium fertilization of crops

Selenium is an essential micronutrient for humans and animals, required to increase immunity, protect cells from free radical damage and inflammation, and support a healthy metabolism. The typical manifestations of selenium deficiency in humans are loss of appetite, fatigue after even mild exercise, cardiac arrhythmia and palpitations, cardiac insufficiency, cardiomegaly, and congestive heart failure, swelling in the joints of arms and legs in children aged 5–13 years resulting in structural shortening of the fingers and long bones resulting in growth retardation and stunting. Clinical signs of selenium deficiency in cattle include mastitis, perinatal death and abortions, suboptimal fertility in adult cattle and suboptimal milk production, acute nutritional muscular dystrophy in young calves, sudden collapse or death of calves within 2–3 days of birth, stiff-legged gait, weakness and inability to stand or walk in young calves.Being a micronutrient for humans and animals, the margin between deficiency and toxicity of selenium are small and selenium supplementation has to be carefully planned. Agronomic biofortification by fertilizing crops on selenium deficient soils is the safest way and has been successfully tried in China and Finland. It is now practised in Australia and several other countries. However, the research work on selenium in soils, plants, animals and humans is of recent origin in India and needs utmost attention and priority considering its importance in the food chain.

Necessity and Content of Swing Phase Gait Coordination Training Post Stroke; A Case Report

Background/Problem: Standard neurorehabilitation and gait training has not proved effective in restoring normal gait coordination for many stroke survivors. Rather, persistent gait dyscoordination occurs, with associated poor function, and progressively deteriorating quality of life. One difficulty is the array of symptoms exhibited by stroke survivors with gait deficits. Some researchers have addressed lower limb weakness following stroke with exercises designed to strengthen muscles, with the expectation of improving gait. However, gait dyscoordination in many stroke survivors appears to result from more than straightforward muscle weakness. Purpose: Thus, the purpose of this case study is to report results of long-duration gait coordination training in an individual with initial good strength, but poor gait swing phase hip/knee and ankle coordination. Methods: Mr. X was enrolled at >6 months after a left hemisphere ischemic stroke. Gait deficits included a ‘stiff-legged gait’ characterized by the absence of hip and knee flexion during right mid-swing, despite the fact that he showed good initial strength in right lower limb quadriceps, hamstrings, and ankle dorsiflexors. Treatment was provided 4 times/week for 1.5 h, for 12 weeks. The combined treatment included the following: motor learning exercises designed for coordination training of the lower limb; functional electrical stimulation (FES) assisted practice; weight-supported coordination practice; and over-ground and treadmill walking. The FES was used as an adjunct to enhance muscle response during motor learning and prior to volitional recovery of motor control. Weight-supported treadmill training was administered to titrate weight and pressure applied at the joints and to the plantar foot surface during stance phase and pre-swing phase of the involved limb. Later in the protocol, treadmill training was administered to improve speed of movement during the gait cycle. Response to treatment was assessed through an array of impairment, functional mobility, and life role participation measures. Results: At post-treatment, Mr. X exhibited some recovery of hip, knee, and ankle coordination during swing phase according to kinematic measures, and the stiff-legged gait was resolved. Muscle strength measures remained essentially constant throughout the study. The modified Ashworth scale showed improved knee extensor tone from baseline of 1 to normal (0) at post-treatment. Gait coordination overall improved by 12 points according to the Gait Assessment and Intervention Tool, Six Minute Walk Test improved by 532′, and the Stroke Impact Scale improved by 12 points, including changes in daily activities; mobility; and meaningful activities. Discussion: Through the combined use of motor learning exercises, FES, weight-support, and treadmill training, coordination of the right lower limb improved sufficiently to exhibit a more normal swing phase, reducing the probability of falls, and subsequent downwardly spiraling dysfunction. The recovery of lower limb coordination during swing phase illustrates what is possible when strength is sufficient and when coordination training is targeted in a carefully titrated, highly incrementalized manner. Conclusions/Contribution to the Field: This case study contributes to the literature in several ways: (1) illustrates combined interventions for gait training and response to treatment; (2) provides supporting case evidence of relationships among knee flexion coordination, swing phase coordination, functional mobility, and quality of life; (3) illustrates that strength is necessary, but not sufficient to restore coordinated gait swing phase after stroke in some stroke survivors; and (4) provides details regarding coordination training and progression of gait training treatment for stroke survivors.

The contralateral knee may not be a valid control for biomechanical outcomes after unilateral total knee arthroplasty

BackgroundAlthough unilateral symptoms and unilateral total knee arthroplasty (TKA) are common, many patients have bilateral radiographic osteoarthritis (OA). Because the contralateral (non-operated) limb is often used as a comparison for clinical and biomechanical outcomes, it is important to know if the presence of OA influences movement patterns in either limb. Research questionThe purpose of this study was to compare bilateral sagittal plane biomechanics between subjects with and without contralateral knee OA after unilateral TKA. MethodsFifty-three subjects who underwent unilateral TKA underwent three-dimensional gait analysis 6–24 months after surgery participated in this cross-sectional study. Kellgren-Lawrence (KL) OA severity in the contralateral limb was measured, and subjects were classified into either a non-OA (KL 0 or 1) or OA (KL 2–4) group. Mixed-model ANOVA tests with factors of group and limb were used to compare biomechanical measures. In the presence of a significant interaction effect, post-hoc comparisons were performed. ResultsThe OA group had more knee flexion at initial contact, less knee flexion and extension excursions, and less knee extension in the contralateral limb compared to the non-OA group. The non-OA group had significant differences between limbs, with more knee flexion at initial contact, less knee joint excursion, and less peak knee extension on the operated limb compared to the contralateral limb, whereas there were no limb differences for the OA group. Kinetic variables were not different in the ANOVA models. Significance and interpretationSubjects with contralateral knee OA have more symmetrical gait, although they adopt a more abnormal and stiff-legged gait pattern bilaterally. Researchers and clinicians should consider radiographic disease severity, not just symptoms, in the contralateral limb when identifying appropriate subject samples for unilateral biomechanical studies. Symmetrical movement patterns between limbs after surgery should not be the sole factor upon which movement recovery is based.

WDR26 Haploinsufficiency Causes a Recognizable Syndrome of Intellectual Disability, Seizures, Abnormal Gait, and Distinctive Facial Features

We report 15 individuals with de novo pathogenic variants in WDR26. Eleven of the individuals carry loss-of-function mutations, and four harbor missense substitutions. These 15 individuals comprise ten females and five males, and all have intellectual disability with delayed speech, a history of febrile and/or non-febrile seizures, and a wide-based, spastic, and/or stiff-legged gait. These subjects share a set of common facial features that include a prominent maxilla and upper lip that readily reveal the upper gingiva, widely spaced teeth, and a broad nasal tip. Together, these features comprise a recognizable facial phenotype. We compared these features with those of chromosome 1q41q42 microdeletion syndrome, which typically contains WDR26, and noted that clinical features are consistent between the two subsets, suggesting that haploinsufficiency of WDR26 contributes to the pathology of 1q41q42 microdeletion syndrome. Consistent with this, WDR26 loss-of-function single-nucleotide mutations identified in these subjects lead to nonsense-mediated decay with subsequent reduction of RNA expression and protein levels. We derived a structural model of WDR26 and note that missense variants identified in these individuals localize to highly conserved residues of this WD-40-repeat-containing protein. Given that WDR26 mutations have been identified in ∼1 in 2,000 of subjects in our clinical cohorts and that WDR26 might be poorly annotated in exome variant-interpretation pipelines, we would anticipate that this disorder could be more common than currently appreciated.

Dystonia of the lower limb after sacral neuromodulation implanted to a 16-year-old boy with non-obstructive chronic urinary retention

Sacral neuromodulation is usually used to treat non-obstructive urinary retention when other forms of treatment have failed. An improvement greater than 50% in urinary symptoms after 40 months of follow-up has been shown: – moreover, it also has few complications: infections, technical failures, discomfort; – we report a case of dystonia of the lower limb, appeared after sacral neuromodulation implantation. MMP is a 16-year-old boy with early puberty as noteworthy medical history. It began in 2012, with dysuria and a loss of urinary feeling (not improved by antibiotics and anticholinergics), after a viral diarrhea episode with abdominal pain treated with morphine. In 2013, he had an acute painless urinary retention after a viral infection and had a bladder catheter for 3 weeks, then a neuromodulation of the 3rd sacral nerve was implanted with disappearance of the urinary symptoms. However, a few months later, a dystonia of the right lower limb appeared, with a shaking limb at knee flexion, a stiff-legged gait and claw toes. The cerebral and spine MRI, the lumbar puncture were normal. When the sacral neuromodulation was stopped, the dystonia declined, but he had several urinary retentions and used self-catheterizations with difficulties and pain. In our hospital (March 2016), neuromodulation was on, with no more effectiveness on the urinary symptoms, but the dystonia and claw toes were still there. When neuromodulation was stopped, claw toes disappeared. We also did a motor branch block of the rectus femoris and after 30 minutes, the knee flexion was nearly complete without any dystonia, and the gait was normal. This dystonia of the lower limb was probably due to the sacral neuromodulation because it appeared when it was on, and had intensity correlated to the intensity of the stimulation. However, it may have a psychological part to this process because such side effect has never been described before and the motor block was very quickly effective.

Alterations in cerebellar physiology are associated with a stiff-legged gait in Atcayji-hes mice

Recent evidence suggests that dystonia, a movement disorder characterized by sustained involuntary muscle contractions, can be associated with cerebellar abnormalities. The basis for how functional changes in the cerebellum can cause dystonia is poorly understood. Here we identify alterations in physiology in Atcayji-hes mice which in addition to ataxia, have an abnormal gait with hind limb extension and toe walking, reminiscent of human dystonic gait. No morphological abnormalities in the brain accompany the dystonia, but partial cerebellectomy causes resolution of the stiff-legged gait, suggesting that cerebellar dysfunction contributes to the dystonic gait of Atcayji-hes mice. Recordings from Purkinje and deep cerebellar nuclear (DCN) neurons in acute brain slices were used to determine the physiological correlates of dystonia in the Atcayji-hes mice. Approximately 50% of cerebellar Purkinje neurons fail to display the normal repetitive firing characteristic of these cells. In addition, DCN neurons exhibit increased intrinsic firing frequencies with a subset of neurons displaying bursts of action potentials. This increased intrinsic excitability of DCN neurons is accompanied by a reduction in after-hyperpolarization currents mediated by small-conductance calcium-activated potassium (SK) channels. An activator of SK channels reduces DCN neuron firing frequency in acute cerebellar slices and improves the dystonic gait of Atcayji-hes mice. These results suggest that a combination of reduced Purkinje neuron activity and increased DCN intrinsic excitability can result in a combination of ataxia and a dystonia-like gait in mice.

Moldy Rice Straw Poisoning in Dairy Cattle in Kathmandu Valley Nepal

An Unidentified disease characterized by hypersensitivity, incoordination, a peculiar stiff-legged gait of the hind legs, severe generalized tumors of the skeletal muscles, progressive paresis, paralysis and constipation and death was reported in a cattle herd of 82 in Kathmandu valley which was maintained in moldy rice straw feeding. The most notable gross pathological lesions in one bull and two cows which died were degenerative and necrotic changes in certain skeletal muscles, hemorrhages on the serosal surfaces, especially on the dorsal aspect of the rumen, and gastro-intestinal stasis. Samples of rice straw, feed and tissue samples of rumen,reticulum,liver revealed the growth of fungus species penicillum and when rest of animals in herds were treated with Anti Deg Nala liquor the general health of rest of animal still feeding the rice straw and same sources of feed improved and mortality checked.

Muscle paresis and passive stiffness: Key determinants in limiting function in Hereditary and Sporadic Spastic Paraparesis

BackgroundPeople with Hereditary and Sporadic Spastic Parapresis (SP) walk with a stiff legged gait characterised by a lack of knee flexion. ObjectiveWe investigated the relationship between lower limb strength and stiffness and knee flexion during swing phase while walking in 20 people with SP and 18 matched controls. MethodsMaximal isometric strength was measured using a dynamometer. Passive stiffness and spasticity was assessed during motor-driven slow (5°/s) and fast (60°/s) stretches at the ankle and knee while the subject was relaxed or preactivating the muscle. Walking was assessed using 3D motion analysis. ResultsIsometric muscle strength was decreased in people with SP with over a 50% reduction in strength being found in the ankle dorsiflexors. Passive stiffness, assessed during slow stretches, was 35% higher in the plantarflexors in people with SP (P<0.05). Faster stretches induced large stretch evoked muscle activity and over a 110% increase in stiffness at the ankle and knee in people with SP reflecting the presence of spasticity (P<0.05). However, stretch reflex size and stiffness was similar between the groups following identical stretches of the pre-activated muscle (P>0.05). Lower knee flexion during swing phase was associated with reduced knee flexion velocity at the end of stance phase which in turn was associated with reduced plantarflexor strength and increased passive stiffness in the knee extensors. ConclusionsThe relative importance of muscle paresis and passive stiffness in limiting walking in SP suggests that these impairments should be the target of future therapies.

Long‐term plasma levels of leptin and adiponectin in Rett syndrome

Rett syndrome is a progressive neurological disorder affecting almost exclusively females after age 6 months and characterised by acquired microcephaly, psychomotor retardation, growth failure, purposeless hand movements, autistic-like behaviour and wide-based and stiff legged gait. Leptin and adiponectin, peptides secreted by adipose tissue, are involved in the regulation of body weight and energy expenditure. We investigated in patients with Rett syndrome the variations of plasma leptin and adiponectin and their relation over a 2-year period. Sixteen female patients, mean age at the basal time 9.4 +/- 4.3 years, with classical Rett syndrome were enrolled. Controls were 16 healthy female subjects, mean age at the basal time 9.9 +/- 3.4 years. Blood samples were withdrawn in the morning at the baseline, 12 months after and 24 months after; plasma leptin and adiponectin concentrations were detected by ELISA. In patients, leptin concentrations significantly increased, while adiponectin concentrations significantly decreased. Both leptin and adiponectin values were significantly higher than those found in controls at each time. Leptin significantly correlated with adiponectin in patients, while there was not a significant correlation in controls. Since all patients were not obese, we might hypothesize that in Rett syndrome leptin and adiponectin might participate to clinical manifestations other than weight balance.

Poster 350: The Effects of Passive Cyclic Stretching on Quadriceps Spasticity in Patients With Spastic Stiff-Legged Gait

Objective: This study was designed to evaluate the effects of passive cyclic stretching on quadriceps spasticity, and to determine the effective parameters of stretching regarding angular velocity and hold time. Design: This study used a randomized repeated measures trial design. Participants: 24 legs of 16 patients with upper motor neuron lesion were recruited. 13 legs were included in a control group and took rest for 15 minutes; 11 legs were included in the treatment group and took stretching for 15 minutes.

Poster 51: The Effects of Passive Cyclic Stretching on Quadriceps Spasticity in Patients With Spastic Stiff-Legged Gait

Poster 51: The Effects of Passive Cyclic Stretching on Quadriceps Spasticity in Patients With Spastic Stiff-Legged Gait

It’s a Dog’s Life

“Mom!” “Hhhnmmm,” I groan, annoyed that my 7-year-old son’s always urgent voice penetrates the closed door of my bedroom, the sound machine, and the fan, all meant to help me sleep before my night shift. “Come quick; it’s Etta.” My irritation evaporates. I hear the worry in his voice, followed by the sounds of feet racing and stumbling down the stairs. I run too, following a trail of watery diarrhea. As I careen into the kitchen, I see Etta, our 10-year-old black lab. My husband, Ned, and son, Rees, are staring, horrified. Etta, usually an energy explosion, is swaying unsteadily, bewildered and close to collapse. She is trembling uncontrollably, salivating profusely, and laboring to breathe. Directing my stunned family, I suppress my rising panic. Ned lifts Etta into our car. Rees follows, and we race for the animal hospital. Once there, Ned hefts our 90-pound lab from the soiled car, and we move as quickly as we can to the emergency entrance. We pass a middle-aged couple, exiting as we enter, propping each other up, empty handed, animal-less. We avoid their eyes. Luckily, just as we enter, the critical care specialist approaches the registration desk. She makes a quick assessment of the situation while I tell her the story. She leads Etta away, noting her halting, stiff-legged gait. I’m handed a clipboard with admission paperwork and told to sit. We breathe a communal sigh of relief. We made it. A doctor, help. Etta has probably been poisoned. SLUDGE, salivation, lacrimation, urination, defecation, emesis. She has most of these symptoms. Where did she get an organophosphate? Oh my god, it must be the old lady who lives next door. She’s never liked Etta. Her yard is full of weeds, old bottles, a shopping cart, all types of trash. She’s probably putting out poison. Suddenly, I want out of this waiting room. How many times do I make nervous family members stew in my waiting room? I want to be in the back, next to Etta, talking to the vet, involved. “She will be OK, won’t she, momma?” My son’s quiet voice breaks into my thoughts. I turn. Rees’ hazel eyes mirror mine. “I think so Rees.” But truthfully I’m uncertain. I stifle my urge to invade the treatment area. I don’t trust them to figure it out. To my relief, the vet reappears to ask more questions.

Camp to clinic: a refugee journey

The dark storm clouds on the horizon at dusk are typical of the wet season in Sudan. On this particular day the wind that normally heralds the daily drenching of our compound had abated. It almost seemed it was in reverence to Tik, an 8-year-ol Dihka girl, walking home leaning on her father and using a sticl to compensate for her stiff-legged gait. A simple leg woun fo Tik had translated into 3 weeks of painful muscle spasms as a result of tetanus. After successful treatment with diazepam, antibiotics and nutritional support; she was going home to her tent in the refugee camp. Another tent in the camp sheltered severely malnourished children receiving food and meddicine from a non-government organisation in this remote area of war-torn Sudan.

Gait analysis role in long-term rehabilitation program in stiff-legged gait

The purpose was to determine the effects of a gastrocnemius stretching program on passive ankle dorsiflexion range of motion and ankle dorsiflexion and time-to-heel-off during the stance phase of gait.This study was a randomized-control trial design.The study was conducted in a biomechanical laboratory setting.Nineteen volunteers (17 women and 2 men, mean age=30.3 years; SD=9.8 years), with less than 8° of passive ankle dorsiflexion range of motion bilaterally and a history of lower extremity overuse injury were randomly assigned to the experimental (n=11) or control group (n=8).The experimental group participated in a static gastrocnemius stretching program of five repetitions held for 30-s, two times daily, for 3 weeks. The control group received no intervention.Passive ankle dorsiflexion range of motion and ankle dorsiflexion and time-to-heel-off during the stance phase of gait were measured before and after the intervention.The experimental group had significantly greater passive dorsiflexion range of motion at post-test than the control group on both the right (p=0.000) and left (p=0.002) sides. Ankle dorsiflexion and time-to-heel-off during the stance phase of gait were not different among group, time, or foot (p>0.05).A gastrocnemius stretch performed two times daily, for 3 weeks increased passive ankle dorsiflexion, but did not alter ankle dorsiflexion or time-to-heel-off during the stance phase of gait. Thus, when an increase in ankle dorsiflexion or time-to-heel-off during the stance phase of ambulation is a clinical goal, it is unlikely to result from the stretching regimen used in this study.

HIP JOINT POSITION AFFECTS VOLITIONAL KNEE EXTENSOR ACTIVITY POST-STROKE.

Purpose/Hypothesis: Individuals post-stroke often exhibit significant functional limitations due to either inadequate or inappropriate volitional muscle activation. In the lower extremity this is particularly apparent during ‘spastic paretic stiff-legged gait’, which has been attributed to excessive quadriceps activity during the stance to swing transition. The mechanism underlying the altered volitional activation of the knee extensors has yet to be elucidated; however, evidence from animal and human models has demonstrated the importance of hip angle sensors in modulating lower extremity muscle activity. Although the hip's position has become a focus for retraining ‘normal’ walking patterns following stroke, there are as of yet, no quantitative studies which examined the influence of hip angle afferent information during isolated volitional muscle activation after stroke. The purpose of this study was therefore to quantify the role of hip joint positioning on the volitional activation of the uniarticular knee extensor muscles after stroke. It was hypothesized that greater hip flexion would yield greater quadriceps activity. Number of Subjects: Fourteen subjects with chronic (> 1 yr) stroke were recruited for testing. Materials/ Methods: Subjects were positioned on a Biodex dynamometer to record the electromyographic (EMG) activity from the uniarticular knee extensor muscles [vastus lateralis (VL) and vastus medialis (VM)] during maximum voluntary isometric knee extension contractions. The knee was fixed at 60°, while hip position was fixed by altering the subject's posture in random order to include: sitting upright (90°), semi-reclined (45°), and supine (0°). EMG data was full wave rectified and low pass filtered to produce a linear envelope. The outcome variable of interest was the integrated EMG activity around peak torque production. A two-way (muscle and hip position) repeated-measures ANOVA (repeated for hip position) was used to determine the effect of varying hip posture on knee extensor activity. Results: Hip position had a substantial effect on the amount of volitional VL and VM muscle activity produced (p=0.07). With the hip positioned in full extension, both muscles were volitionally activated significantly less than when the hip was positioned in flexion (p=0.03). Conclusions: The angle of the hip joint appears to play a significant role in the volitional activation of the uniarticular knee extensors, although more data is required. Patients with stroke tend to walk with the hips in greater flexion, which may facilitate activation of the knee extensors contributing to ‘stiff knee gait’ pattern. Clinical Relevance: Hip joint angle contributes to the modulation of volitional quadriceps activation and likely influences reflexive/spastic activation contributing to inappropriate muscle activity during functional activities. A strong emphasis should therefore be placed on hip joint posturing during gait retraining to assist with appropriate muscle activation patterns.

Groin Injury - Golf

0746 HISTORY – A 50-year-old right-handed male sustained an acute right groin injury while teeing off on the first tee. He golfed infrequently, with this being the first round in over a year. In addition, he admitted to an abbreviated warm-up. He reported a sensation in his right groin accompanied by immediate pain as he rotated and extended his hips to the left during the downswing of the tee shot with a driver. Though limping in pain, he was able to complete the round, and 24–48 hours later noted significant bruising and swelling in his right medial thigh. At that same time, he noted some subjective weakness without numbness or tingling. He reported to our Sports Medicine Clinic nine days after the injury. PHYSICAL EXAMINATION – Clinical examination revealed a slightly antalgic and stiff-legged gait. Ecchymosis extended from the femoral triangle to the adductor tubercle distally, and included the posteromedial thigh. Significant tenderness was noted from the superior pubic ramus to the mid-body of the adductor longus, with less dramatic tenderness over the ischial tuberosity. No defect was palpable. Passive coronal plane abduction was right 35 degrees and left 50. Pain was reproduced with active supine straight-leg raise, resisted adduction and abduction in neutral, and resisted extension in the supine position. Proximal and distal neurovascular status was intact. No diagnostic imaging available at time of initial evaluation. DIFFERENTIAL DIAGNOSIS: Right adductor longus muscle strain, moderate to high grade Avulsion injury at the superior pubic ramus Associated hamstring strain TESTS AND RESULTS: Pelvis anterior-posterior radiographs: – negative for bony avulsion – degenerative arthritis bilateral hips Right hip lateral and oblique radiographs: – negative for bony avulsion MRI pelvis and proximal right thigh: – partial tear of adductor longus with associated large intramuscular hematoma – proximal and distal adductor longus tendons intact without evidence of avulsion – mild strain of the pectineus and adductor brevis muscles FINAL/WORKING DIAGNOSIS: Grade 2 right adductor longus strain TREATMENT AND OUTCOMES: Protected range of motion, crutch-assisted weight bearing, ice, compression. 2 weeks post-injury began submaximal isometric strengthening of the adductors. Plan to advance to multiplanar isodynamic strengthening as able.

Motor branch of the rectus femoris: anatomic location for selective motor branch block in stiff-legged gait

Sung DH, Jung J-Y, Kim H-D, Ha BJ, Ko YJ. Motor branch of the rectus femoris: anatomic location for selective motor branch block in stiff-legged gait. Arch Phys Med Rehabil 2003;84:1028-31. Objective:To determine the ideal target point for selective motor branch block of the rectus femoris to treat stiff-legged gait. Design:Descriptive study. Setting:Anatomic institute of a university school of medicine in Korea. Cadavers:Twenty-two preserved adult cadavers. Intervention:The anterior thigh of the cadaver was dissected below the inguinal ligament. The motor branches of the 4 heads of the quadriceps were identified and traced from just below the inguinal ligament to the motor points. Main Outcome Measures:The point T, where the motor branch of the rectus femoris is divided into smaller subbranches, was identified. Its location in relation to the surface anatomic landmarks was determined on the basis of the 2 anatomic lines that connect the anterior superior iliac spine to the medial femoral condyle, and the issuing spot of the femoral nerve below the inguinal ligament to the middle of the superior pole of the patellar. Results:The motor branch of the rectus femoris was divided into 2 subbranches at point T just before it reached the muscle. It nearly touched the medial margin of the rectus femoris at a proximal one-fourth to one-fifth point on 2 anatomic lines. The superior subbranch penetrated the muscle fascia at the posterior surface of the proximal one third of the muscle, whereas the inferior subbranch penetrated the muscle fascia at the medial border of the muscle. Conclusion:The point T is the most suitable target point to selectively block the motor branch of the rectus femoris without affecting the other 3 motor branches of the femoral nerve in the treatment of stiff-legged gait.