Asymmetric leg activity in healthy subjects during walking, detected by electrogoniometry

Some Insights Regarding Symmetry Relevance in Biomedicine

The subject of symmetry has always been a matter of interest in biomedicine, particularly in exercise physiology and biomechanics [...]

Symmetry and spatial distribution of muscle glucose uptake in the lower limbs during walking measured using FDG-PET

Purpose

This study aimed to elucidate whether muscle activity (in terms of glucose uptake) between the legs can be considered symmetrical during walking. Furthermore, we aimed to determine whether the [¹⁸F]-fluorodeoxyglucose was distributed heterogeneously throughout each muscle, and if so, whether areas of high uptake would be clustered.

Methods

Ten healthy participants walked on a treadmill at self-selected comfortable walking speed for a total of 90 minutes, 60 minutes before and 30 minutes after intravenous injection of 50 MBq [¹⁸F]-fluorodeoxyglucose. Thereafter, a positron emission tomography/computed tomography scan of the lower limb was acquired. Three-dimensional muscle contours of 78 (= 39x2) muscles of the left and right lower limb were semi-automatically determined from magnetic resonance imaging scans. After non-rigid registration, those muscle contours were used to extract [¹⁸F]-fluorodeoxyglucose uptake from the positron emission tomography scans.

Results

Large asymmetries were observed in the lower leg muscles (e.g. median absolute asymmetry index of 42% in the gastrocnemius medialis) and in the gluteus minimus (30% asymmetry) and gluteus medius (15% asymmetry), whereas the uptake in the thighs was relatively symmetrical between the limbs (<6% asymmetry). These were not related to limb-dominance nor to inter-limb differences in muscle volume. The [¹⁸F]-fluorodeoxyglucose distribution was not distributed normally; most voxels had a relatively low standardized uptake value, and a minority of voxels had a relatively high standardized uptake value. The voxels with higher [¹⁸F]-fluorodeoxyglucose uptake were distributed heterogeneously; they were clustered in virtually all muscles.

Conclusion

The findings in this study challenge the common assumption of symmetry in muscle activity between the limbs in healthy subjects. The clustering of voxels with high uptake suggests that even in this prolonged repetitive task, different spatial regions of muscles contribute differently to walking than others.

The laterality of the gallop gait in Thoroughbred racehorses

Laterality can be observed as side biases in locomotory behaviour which, in the horse, manifest inter alia as forelimb preferences, most notably in the gallop. The current study investigated possible leading-leg preferences at the population and individual level in Thoroughbred racehorses (n = 2095) making halt-to-gallop transitions. Videos of flat races in the UK (n = 350) were studied to record, for each horse, the lead-leg preference of the initial stride into gallop from the starting stalls. Races from clockwise (C) and anti-clockwise (AC) tracks were chosen alternately at random to ensure equal representation. Course direction, horse age and sex, position relative to the inside rail and finishing position were also noted. On C courses, the left/right ratio was 1.15, which represents a significant bias to the left (z = –2.29, p = 0.022), while on AC courses it was 0.92 (z = 0.51, p = 0.610). In both course directions, there was no significant difference between winning horses that led with the left leading leg versus the right (C courses, z = –1.32, p = 0.19 and AC courses, z = –0.74, p = 0.46). Of the 2,095 horses studied 51.26% led with their L fore and 48.74% with their R, with no statistically significant difference (z = -1.16, p = 0.25). Therefore, there was no evidence of a population level motor laterality. Additionally, 22 male and 22 female horses were randomly chosen for repeated measures of leading leg preference. A laterality index was calculated for each of the 44 horses studied using the repeated measures: 22 exhibited right laterality (of which two were statistically significant) and 21 exhibited left laterality (eight being statistically significant); one horse was ambilateral. Using these data, left lateralized horses were more strongly lateralized on an individual level than the right lateralized horses (t = 2.28, p = 0.03, DF = 34) and mares were more left lateralized than males (t = 2.4, p = 0.03, DF = 19).

Balance and postural control in basketball players

Abstract Introduction: Basketball is one of the most popular sports involving gestures and movements that require single-leg based support. Dorsiflexion range of motion (DROM), balance and postural control may influence the performance of this sport. Objective: To compare and correlate measures of balance, postural control and ankle DROM between amateur basketball athletes and non-athletes. Methods: Cross-sectional study, composed by 122 subjects allocated into one control group (CG = 61) and one basketball group (BG = 61). These groups were subdivided into two other groups by age: 12-14 years and 15-18 years. The participants were all tested for postural balance with the Star Excursion Balance Test (SEBT), postural control with the Step-down test and DROM with the Weight-bearing lunge test (WBLT). Between-groups differences were compared using repeated-measures multivariate analysis of variance. Normalized reaching distances were analyzed and correlated with the WBLT and Step-down test. Results: There was no difference in the scores of WBLT (P = .488) and Step-down test (P =. 916) between the groups. Scores for the anterior reach (P = .001) and total score of SEBT (P = .030) were higher in BG. The values for the posterolateral (P = .001) and posteromedial reach (P = .001) of SEBT were higher in BG at the age of 15-18. The correlation between the anterior reach of the SEBT and WBLT was significant in BG between 12-14 years (r = 0.578, P = .008), and in the CG between 15-18 years (r = 0.608, P=.001). Conclusion: The balance was better in the BG, although adolescents between 15-18 years have better balance control for the posteromedial and posterolateral reaches of the SEBT.

A horse's locomotor signature: COP path determined by the individual limb

Introduction

Ground reaction forces in sound horses with asymmetric hooves show systematic differences in the horizontal braking force and relative timing of break-over. The Center Of Pressure (COP) path quantifies the dynamic load distribution under the hoof in a moving horse. The objective was to test whether anatomical asymmetry, quantified by the difference in dorsal wall angle between the left and right forelimbs, correlates with asymmetry in the COP path between these limbs. In addition, repeatability of the COP path was investigated.

Methods

A larger group (n = 31) visually sound horses with various degree of dorsal hoof wall asymmetry trotted three times over a pressure mat. COP path was determined in a hoof-bound coordinate system. A relationship between correlations between left and right COP paths and degree of asymmetry was investigated.

Results

Using a hoof-bound coordinate system made the COP path highly repeatable and unique for each limb. The craniocaudal patterns are usually highly correlated between left and right, but the mediolateral patterns are not. Some patterns were found between COP path and dorsal wall angle but asymmetry in dorsal wall angle did not necessarily result in asymmetry in COP path and the same could be stated for symmetry.

Conclusion

This method is a highly sensitive method to quantify the net result of the interaction between all of the forces and torques that occur in the limb and its inertial properties. We argue that changes in motor control, muscle force, inertial properties, kinematics and kinetics can potentially be picked up at an early stage using this method and could therefore be used as an early detection method for changes in the musculoskeletal apparatus.

Distribution of plantar pressures during gait in different zones of the foot in healthy children: the effects of laterality

The objective was to determine whether gait is symmetric in healthy children 6-7 years of age and to assess the effects of laterality and the anatomical zone of the foot. 46 children were subjected to gait symmetry analysis in which the plantar and lateral pressures associated with kicking a ball, static balance, and dynamic support were measured. There were no significant differences in the average pressure exerted by the right and left feet based on the laterality of the child. Independent of each laterality test, a greater pressure on the right rearfoot was observed compared to the left rearfoot and on the left midfoot and forefoot compared to the right.

Anatomically asymmetrical runners move more asymmetrically at the same metabolic cost

We hypothesized that, as occurring in cars, body structural asymmetries could generate asymmetry in the kinematics/dynamics of locomotion, ending up in a higher metabolic cost of transport, i.e. more ‘fuel’ needed to travel a given distance. Previous studies found the asymmetries in horses’ body negatively correlated with galloping performance. In this investigation, we analyzed anatomical differences between the left and right lower limbs as a whole by performing 3D cross-correlation of Magnetic Resonance Images of 19 male runners, clustered as Untrained Runners, Occasional Runners and Skilled Runners. Running kinematics of their body centre of mass were obtained from the body segments coordinates measured by a 3D motion capture system at incremental running velocities on a treadmill. A recent mathematical procedure quantified the asymmetry of the body centre of mass trajectory between the left and right steps. During the same sessions, runners’ metabolic consumption was measured and the cost of transport was calculated. No correlations were found between anatomical/kinematic variables and the metabolic cost of transport, regardless of the training experience. However, anatomical symmetry significant correlated to the kinematic symmetry, and the most trained subjects showed the highest level of kinematic symmetry during running. Results suggest that despite the significant effects of anatomical asymmetry on kinematics, either those changes are too small to affect economy or some plastic compensation in the locomotor system mitigates the hypothesized change in energy expenditure of running.

Overload and neovascularization of Achilles tendons in young artistic and rhythmic gymnasts compared with controls: an observational study

The incidence of Achilles tendinopathy is very high in young female gymnasts (17.5 %). According to literature, ecography screenings show the tendons thickening, but at the same time it does not reveal a direct link to the clinical picture. The neovessels are involved in the pathophysiological process of Achilles tendinopathy. For this reason, we wanted to verify there between perfusion tendon values and the type of sport activity. We performed a clinical observational study monitoring the oximetry of the Achilles tendon and the epidemiological data of 52 elite female (artistic and rhythmic) gymnasts versus 21 age-matched controls. Analyzing the main limb, we revealed statistically higher oximetry values in the artistic gymnasts group (69.5 %) compared to the rhythmic gymnasts group (67.1 %) (t = 2.13; p = 0.01) and the sedentary group (66.2 %) (t = 2.70; p = 0.004), but we did not find any differences between rhythmic gymnasts group and the sedentary group (t = 0.68; p = 0.24). The multiple logistic regression model highlighted that the oximetry value of the main limb is not influenced by age, knowledge of the main limb, years of general and gymnastic sports activity (p > 0.05). We discovered an increase of Achilles tendon perfusion in the main limb in the artistic gymnast group. We hypothesize that specific figures of artistic sports activity are responsible for muscle overload and gastrocnemius-soleus group and, at the same time, these figures cause hyperperfusion of the tendon. Prospective longitudinal studies could explain if this could become a predictive sign of the next Achilles tendinopathy onset.

Overload and neovascularization of shoulder tendons in volleyball players

BACKGROUND

In overhead sports like volleyball, the onset of a rotator cuff tendinopathy due to functional overload is a common observation. An angiofibroblastic etiopathogenesis has been hypothesized, whereby a greater anaerobic metabolism occurs in critical zones of the tendon with a lower degree of vascularization; this would induce collagen and extracellular matrix degradation, that could then trigger a compensatory neovascularization response. We performed a clinical observational study of 80 elite volleyball players, monitoring the perfusion values of the supraspinatus tendons by oximetry.

RESULTS

No statistically significant differences were found between the oximetry data and age, sex or years of sports activity, nor when comparing the right and left arm or the dominant and non-dominant arm. A statistically significant difference was found for the dominant arm values in relation to the competitive role, higher values being obtained in outside hitters (62.7%) than middle hitters (53.7%) (p = 0.01), opposite hitters (55.5%) (p = 0.02) and libero players (54.4%) (p = 0.008), whereas there were no differences in setters (56.2%) (p > 0.05).

CONCLUSIONS

The different tendon vascularization values found in players with different roles in the team may be attributed to a response to the specific biomechanical demands posed by the different overhead throwing roles.

The mathematical description of the body centre of mass 3D path in human and animal locomotion

Although the 3D trajectory of the body centre of mass during ambulation constitutes the 'locomotor signature' at different gaits and speeds for humans and other legged species, no quantitative method for its description has been proposed in the literature so far. By combining the mathematical discoveries of Jean Baptiste Joseph Fourier (1768-1830, analysis of periodic events) and of Jules Antoine Lissajous (1822-1880, parametric equation for closed loops) we designed a method simultaneously capturing the spatial and dynamical features of that 3D trajectory. The motion analysis of walking and running humans, and the re-processing of previously published data on trotting and galloping horses, as moving on a treadmill, allowed to obtain closed loops for the body centre of mass showing general and individual locomotor characteristics. The mechanical dynamics due to the different energy exchange, the asymmetry along each 3D axis, and the sagittal and lateral energy recovery, among other parameters, were evaluated for each gait according to the present methodology. The proposed mathematical description of the 3D trajectory of the body centre of mass could be used to better understand the physiology and biomechanics of normal locomotion, from monopods to octopods, and to evaluate individual deviations with respect to average values as resulting from gait pathologies and the restoration of a normal pattern after pharmacological, physiotherapeutic and surgical treatments.

Reliability and validity of a new ankle electrogoniometer

OBJECTIVES

To establish reliability, accuracy and concurrent validity of a new electrogoniometer (SG110A, Biometrics) for measuring ankle movement.

METHODS

The new electrogoniometer, placed at the lateral malleolus (A-perp), was compared to a customary electrogoniometer (SG110, Biometrics), placed along the Achilles tendon (A-para). Concurrent recordings were made with motion analysis. Common dance movements were performed by 17 dancers on two days. Intraclass correlation coefficients (ICC) and standard error of measurement (SEM) were calculated for sagittal angular displacements.

RESULTS

Instrument and intra-tester reliability of A-perp was high (r >or= 0.985, r >or= 0.979, respectively). Criterion and concurrent validity were also high (r >or= 0.954, r >or= 0.937). SEM ranged from 1.43 degrees to 6.99 degrees.

CONCLUSIONS

The high ICC values establish acceptable reliability and validity. Subjects found A-perp more comfortable. Although both electrogoniometers are acceptable (comparable SEM) to measure extreme ankle motions, the greater comfort and durability of the new A-perp sensor is advantageous.

Dairy farm worker exposure to awkward knee posture during milking and feeding tasks

Musculoskeletal disorders are common among agricultural workers, particularly among dairy farm workers. Specifically, dairy farm workers have been identified as being at risk for knee osteoarthritis. Physical risk factors that may contribute to knee osteoarthritis include awkward postures of the knee, such as kneeling or squatting. The purpose of this study was to quantify exposure to awkward knee posture among dairy farm workers during milking and feeding tasks in two common types of milking facilities (stanchion and parlor). Twenty-three dairy farm workers performed milking and feeding tasks; 11 worked in a stanchion milking facility, and 12 worked in a parlor milking facility. An electrogoniometer was used to measure knee flexion during 30 min of the milking and feeding tasks. Milking in a stanchion facility results in a greater duration of exposure to awkward posture of the knee compared with milking in a parlor facility. Specifically, the percentage of time in >or=110 degrees knee flexion was significantly greater in the stanchion facility (X = 17.7; SE 4.2) than in the parlor facility (X = 0.05; SE 0.04; p <or= 0.05). Similar results were observed with other categories of awkward knee posture in both milking and feeding tasks. This study supports previous findings that working in stanchion milking facility results in greater exposure to awkward knee posture compared with working in a parlor milking facility.

The relationship of movement time to hand-foot laterality patterns

Asymmetries in movement times of the hands in 60 healthy participants with different patterns of hand-foot dominance were investigated. Handedness and footedness were assessed by means of questionnaires and verified by simple motor tasks. Psychomotor performance was evaluated by the use of selected tests from the computerised Vienna Test System (VST, Vienna, Austria). Movement time (MT) was assessed separately for dominant and non-dominant hands in a unimanual simple reaction task. Participants performed significantly better with their preferred hand, and differences in performance between right- and left-handers were not significant, neither was there a main effect of foot dominance on MT of the hands. However there was a significant effect of laterality pattern in hand-foot combination on hands MT: participants with cross-lateral dominance patterns of hands and feet performed significantly better than those with congruent hand-foot dominance. No significant interaction with sex was found. These results provide evidence for a lack of independence of hand and foot dominance in motor performance, suggesting the functional significance of limb laterality pattern in the motor control system. The results support the hypothesis that the quality of human hand movements may be influenced not only by central information processing (hemispheric specialisation) but also by other structures and processes of motor control, such as central pattern generators (CPGs) and biomechanical factors.

Disability in patients with chronic patellofemoral pain syndrome: a randomised controlled trial of VMO selective training versus general quadriceps strengthening

This study was a prospective single blind randomised controlled trial to compare the effects of rehabilitation with emphasis on retraining the vastus medialis (VMO) component of the quadriceps femoris muscle and rehabilitation with emphasis on general strengthening of the quadriceps femoris muscles on pain, function and Quality of Life in patients with patellofemoral pain syndrome (PFPS). Patients with PFPS (n=69) were recruited from a hospital orthopaedic clinic and randomised into three groups: (1) physiotherapy with emphasis on selectively retraining the VMO (Selective); (2) physiotherapy with emphasis on general strengthening of the quadriceps femoris muscles (General); and (3) a no-treatment control group (Control). The three groups were then compared before and after an eight-week rehabilitation period. The Selective and General groups demonstrated statistically significant and 'moderate' to 'large' effect size reductions in pain when compared to the Control group. Both the Selective and General groups displayed statistically significant and 'moderate' and 'large' effect size improvements in subjective function and Quality of Life compared to the Control group. Knee flexion excursion during the stance phase of gait, demonstrated that there were no statistical significant differences and only 'trivial' to 'small' effect size differences between the Selective or General groups and the Control group. A large number of PFPS patients can experience significant improvements in pain, function and Quality of Life, at least in the short term, with quadriceps femoris rehabilitation, with or without emphasis on selective activation of the VMO component. Both approaches would seem acceptable for rehabilitating patients with PFPS. It may be appropriate to undertake exercises involving selective activation of the vastus medialis early in the rehabilitation process, however, clinicians should not overly focus on selective activation before progressing rehabilitation, especially in more chronic cases with significant participation restrictions.

Is laterality associated with a higher rate of hip arthroplasty on the dominant side?

The authors analyzed data collected by the Registry of the Orthopedic Prosthetic Implantology in Italy. They found a higher rate of total hip arthroplasty on the right side (58%) in comparison with the left side in patients affected by primary coxarthrosis. To test whether laterality was the cause of this, they checked the prevalence of the upper and lower limbs in 262 patients treated for monolateral total hip prosthesis. They found that the percentage of left-handed patients was very low (0.8-6.5%). The percentage of left-footed patients was, instead, 26.5% for power tasks. They observed that, while the rate of arthroplasties on the right side was similar to that of the left side (50.7 and 49.3%) in the right-footed patients, there was a clear-cut prevalence in the number of operations on the right hip (76.8%) in comparison to the left one (23.2%) in the left-footed patients. The authors suggested that, in left-footed patients, the right side was subjected to greater stress.

Test–retest stability of an experimental measure of human turning behaviour in right-handers, mixed-handers, and left-handers

Animals turn away from the hemisphere with the more active dopamine (DA) system. For humans, a similar relationship has been assumed, albeit that side preferences obtained from different measures are inconsistent. Given the important role of DA on human behaviour and cognition, a stable human turning measure is of significant experimental value. We assessed the stability (test and retest 4 weeks apart) of veering behaviour (lateral deviations during blindfolded straight ahead walking) in 20 healthy right-handers, 20 mixed-handers, and 20 left-handers. Veering behaviour did not differ between groups, and did not reveal any particular side preference in any group. Relationships of side preferences between testing sessions for the different handedness groups was low for right-handers, and showed some minor consistency for the mixed-handed group. Neither handedness nor footedness was significantly related to preferred veering side. These findings, if not related meaningfully to DA-mediated conditions (e.g., clinical populations, pharmacological studies, personality) in the future, suggests that veering behaviour is an inappropriate alternative to the animal turning model. These findings challenge the reliability of human turning measures, and invite more broadly for a critical evaluation of turning measures as an indicator of hemispheric DA asymmetries in human populations.

Spatial parameters of walking gait and footedness

OBJECTIVE

The present study was undertaken to assess whether footedness has effects on selected spatial and angular parameters of able-bodied gait by evaluating footprints of young adults.

SUBJECTS AND METHODS

A total of 112 males and 93 females were selected from among students and staff members of the University of Malawi using a simple random sampling method. Footedness of subjects was assessed by the Waterloo Footedness Questionnaire Revised. Gait at natural speed was recorded using the footprint method. The following spatial parameters of gait were derived from the inked footprint sequences of subjects: step and stride lengths, gait angle and base of gait. The anthropometric measurements taken were weight, height, leg and foot length, foot breadth, shoulder width, and hip and waist circumferences.

RESULTS

The prevalence of right-, left- and mix-footedness in the whole sample of young Malawian adults was 81%, 8.3% and 10.7%, respectively. One-way analysis of variance did not reveal a statistically significant difference between footedness categories in the mean values of anthropometric measurements (p > 0.05 for all variables). Gender differences in step and stride length values were not statistically significant. Correction of these variables for stature did not change the trend. Males had significantly broader steps than females. Normalized values of base of gait had similar gender difference. The group means of step length and normalized step length of the right and left feet were similar, for males and females. There was a significant side difference in the gait angle in both gender groups of volunteers with higher mean values on the left side compared to the right one (t = 2.64, p < 0.05 for males, and t = 2.78, p < 0.05 for females). One-way analysis of variance did not demonstrate significant difference between footedness categories in the mean values of step length, gait angle, bilateral differences in step length and gait angle, stride length, gait base and normalized gait variables of male and female volunteers (p > 0.05 for all variables).

CONCLUSIONS

The present study demonstrated that footedness does not affect spatial and angular parameters of walking gait.

The reliability of isokinetic testing of the ankle joint and a heel-raise test for endurance

The aim of the present study was to investigate the reliability of different methods used for isokinetic testing of calf muscle strength and endurance. The detailed evaluation of test-retest reliability serves the purpose of establishing reliable research tools when evaluating patients who have sustained an Achilles tendon rupture. The test-retest reliability of isokinetic measurements at the ankle for eccentric and concentric muscle action was calculated in ten healthy male volunteers using intra-class correlation (ICC) and coefficient of variation (CV). Three different positions were compared at the angular velocities of 30 degrees /s and 180 degrees /s for right and left ankles. The ICC for plantar flexion was 0.37-0.95, whilst it was 0.00-0.96 for dorsiflexion. The corresponding CVs were 4.0-19.9 and 2.4-19.8 respectively. The test-retest reliability of standardised heel-raises, Achilles tendon width, calf circumference and ankle range of motion revealed ICC values of 0.71-0.98 and CVs of 0.67-19.1. The test-retest interval was 5 to 7 days. We conclude that all three positions studied for the isokinetic evaluation of calf muscle function are equally reliable concerning plantar flexion at the ankle joint. The same level of reliability was also found in the evaluation of the standing heel-raise test and the isokinetic dorsiflexion test, except for dorsiflexion in the supine position. The reliability of the investigated methods was only fair despite the use of a detailed and standardised test protocol.

Gait Abnormalities in Elderly Fallers

The objective of this study was to measure gait abnormalities in elderly fallers with the Locometrix™ gait-analysis system. This accelerometric device provided the following gait variables: walking speed and stride frequency, length, symmetry, and regularity. The variables were analyzed over a 20-s period of stable walking on a flat track of 40 m. Participants were 20 elderly patients hospitalized for falls (mean age 80.8 ± 5.0 years) and 33 older adults living at home (mean age 77.2 ± 6.5 years). All gait variables were found to be significantly lower in the faller group (p< .05). The lower gait speed, stride length, and stride frequency were previously recognized as nonrelevant in predicting the risk of falling, whereas lower stride symmetry was related to an underlying pathology and lower stride regularity was correlated to the risk of falls. The Locometrix appears to be well suited to measure gait regularity in routine practice.

Functional asymmetries of the lower limbs. A comparison between clinical assessment of laterality, isokinetic evaluation and electrogoniometric monitoring of knees during walking

We used bilateral electrogoniometric gait monitoring of the knees to demonstrate the existence of an angular asymmetry between the two legs in healthy subjects. We also searched for correlations between this asymmetry and handedness, footedness and ocular laterality and isokinetic strength of the flexor-extensor muscles of the two knees. Among the 40 subjects studied, 25 (62.5%) showed an asymmetric maximal knee flexion: the difference being superior or equal to 5 degrees between the knees. There was no correlation between this asymmetry and the lateralities studied. We termed this type of asymmetry 'angular preponderance' to differentiate it from the laterality defined by clinical tests. Isokinetic strength of the knee flexors and extensors was correlated with the gender and speed, but not with side or laterality. Appropriate interpretation of lower limb examination should take into consideration angular gait asymmetry in the healthy subject.