Passive moment about the hip in straight leg raising

Acute effects of static stretching and proprioceptive neuromuscular facilitation on non-local range of movement

Acute effects of static stretching (SS) and proprioceptive neuromuscular facilitation (PNF) on local and non-local range of motion (ROM) were assessed in 29 participants. Three evaluations were performed one week apart: week-1 Control session (CS); weeks 2-3 either SS or PNF interventions (randomized). Dominant and non-dominant limbs, local (hamstring extensibility) and non-local ROMs (Shoulder extension-ShE) were collected at baseline (T0), immediately after (T1), and fifteen minutes post-intervention (T2). No differences were found between time-points during the CS. Local-ROM significantly increased (p=0.0002, ES=0.74 and 0.0079, 0.56, for dominant and non-dominant lower limbs, respectively) after both SS and PNF. No interaction between time and treatment was detected for ShE in both limbs. However, post-hoc analysis revealed a significant increase in dominant upper limb ShE between T0 and T1 only after SS (p=0.002; +6.5%). Acute bouts of SS and PNF can increase local-ROM, however, no clear effects were observed for non-local ROM.

Acute effects of different administration order of stretching exercises: effects on range of motion and cross-over effect

BACKGROUND

The aim of this manuscript is to investigate if stretching exercise administration order may influence outcomes pertinent to range of movement (ROM).

METHODS

A total sample of 108 participants was randomized into five groups. Eight sets of unilateral static stretching (SS) of 30s duration each with a 30s rest were administered to the right leg. One group underwent SS of the knee extensors (KE), another to the knee flexors (KF), another first to the KE and then to the KF, another first to the KF and then to the KE while the last group was used as control (CG). Each group was assessed for ROM of both lower limbs for either the KE and KF motion (passive hip extention [PHE] and passive straight leg raise [PSLR], respectively). Measures were assessed before (T0), immediately after (T1), and 15 minutes after the intervention (T2).

RESULTS

No differences were observed for time (T0 vs. T1 vs. T2) for all measures in the CG for both limbs. Time-x-group interactions were observed only in the intervention limb (P<0.0007 and 0.004, ES 0.73 and 0.55, for KE and KF, respectively). Within the intervention limb, a significant increase in the PHE was observed from T0 to T1 only in the KE and KF/KE groups. For measures of the PSLR, a significant increase was observed from T0 to T1 only in the KF and KE/KF groups. No differences neither for time or group were observed in the control limb.

CONCLUSIONS

Our results highlight that exercise administration order has an effect on ROM outcomes. Measures of ROM significantly increase only for the last stretched muscle in each intervention group. No crossover effect was observed in the contralateral limb.

Positional transversal release is effective as stretching on range of movement, performance and balance: a cross-over study

Background

The aim of this study was to compare the positional transversal release (PTR) technique to stretching and evaluate the acute effects on range of movement (ROM), performance and balance.

Methods

Thirty-two healthy individuals (25.3 ± 5.6 years; 68.8 ± 12.5 kg; 172.0 ± 8.8 cm) were tested on four occasions 1 week apart. ROM through a passive straight leg raise, jumping performance through a standing long jump (SLJ) and balance through the Y-balance test were measured. Each measure was assessed before (T0), immediately after (T1) and after 15 min (T2) of the provided intervention. On the first occasion, no intervention was administered (CG). The intervention order was randomized across participants and comprised static stretching (SS), proprioceptive neuromuscular facilitation (PNF) and the PTR technique. A repeated measure analysis of variance was used for comparisons.

Results

No differences across the T0 of the four testing sessions were observed. No differences between T0, T1 and T2 were present for the CG session. A significant time × group interaction for ROM in both legs from T0 to T1 (mean increase of 5.4° and 4.9° for right and left leg, respectively) was observed for SS, PNF and the PTR. No differences for all groups were present between T1 and T2. No differences in the SLJ and in measures of balance were observed across interventions.

Conclusions

The PTR is equally effective as SS and PNF in acutely increasing ROM of the lower limbs. However, the PTR results less time-consuming than SS and PNF. Performance and balance were unaffected by all the proposed interventions.

Preseason weight-bearing ankle dorsiflexion in male professional football players with and without a history of severe ankle injury: A novel analysis in an English Premier League club

OBJECTIVES

Ankle injuries are common in professional football and have profound player/team/club consequences. The weight-bearing lunge-test (WBLT) assesses ankle dorsiflexion range-of-motion in football primary/secondary injury prevention and performance contexts. Data for uninjured and previously ankle-injured players in the English Premier League (EPL) is not available. This study analysed WBLT measurements (cm) within and between uninjured and previously severe ankle-injured players (injured-stiff group, injured-lax group) in one EPL club.

DESIGN

Cross-sectional.

SETTING

Preseason.

PARTICIPANTS

Forty-nine players (age 22.9 ± 4.6 yr; height 181.6 ± 5.2 cm; mass 77.7 ± 7.6 kg).

MAIN OUTCOME MEASURES

Prevalence (%) of previous unilateral severe ankle injury (USAI). Side-to-side (right/left, dominant/nondominant, injured/uninjured) WBLT comparisons at group-level (t-test [within-group]; Welch's ANOVA [between-group]; effect sizes [within-/between-group]) and individual-level (limb symmetry index [%]; absolute-asymmetry [%]).

RESULTS

Prevalence of USAI was 38.7%. There were no statistically-significant side-to-side differences for within-/between-group comparisons. Effect sizes: just-below-large (injured-stiff) and extremely-large (injured-lax) for within-group injured-side/uninjured-side comparisons; just-below-medium (injured-lax) to just-above-medium (injured-stiff) for injured-side comparisons to uninjured players. Absolute-asymmetries: uninjured players, 15.4±13.2%; injured-stiff, 21.8±33.6%; injured-lax 20.4±13.6%.

CONCLUSIONS

Over one-third of players had previous USAI. Effect sizes indicate substantial within-group side-to-side differences and less substantial between-group differences. Across groups, some players had absolute-asymmetries that may elicit concern in ankle primary/secondary injury prevention and performance contexts.

Contribution of passive moments to inter-segmental moments during gait: A systematic review

Inter-segmental moments computed by inverse dynamic during gait come from active moments, due to muscle contraction, but also from passive moments, resulting from the resistance of the periarticular structures to their deformation. The evaluation of the proportion of the inter-segmental moments that can be attributed to passive moments has led to divergent results. Thus, the purpose of this study was to systematically search and synthesize the evidence of the contribution of passive moments to inter-segmental moments during healthy and pathological gait. A broad systematic search was performed including four databases. Thirteen studies met all inclusion criteria. Results showed that passive moments participate to inter-segmental moments during gait in a non-negligible way. For the ankle, the evaluation of the proportion of inter-segmental moment attributed to passive structures is 5-20% around the push-off. For the knee, this proportion is 40-98% during late swing and 10-80% during the single support phase. For the hip, it is 20-50% at push-off. For pathological population, it has been shown that this contribution may sometimes be more important, either due to a smaller inter-segmental moment or a larger passive moment. These results suggest that passive mechanisms can contribute substantially to normal human gait, facilitating the propulsion or the braking of the joint. Passive structures, acting as elastic springs, thus help to reduce the energy cost of gait. For pathological gait, studying the contribution of passive moments to inter-segmental moments can help to better understand the aetiology of the pathology.

Does passive hip stiffness or range of motion correlate with spinal curvature and posture during quiet standing?

BACKGROUND

It has been postulated that hip muscle stiffness can be inferred from postural assessment, and that predictable relationships exist between passive stiffness of opposing muscles. Despite a lack of evidence to demonstrate such relationships, manual therapy textbooks continue to direct clinicians to treat hip muscles following postural analysis.

RESEARCH QUESTION

Do significant correlations exist between standing posture, and hip muscle stiffness and range of motion?

METHODS

20 participants volunteered for this observational study. Passive hip stiffness was calculated as the derivative of the moment-angle curve measured during leg raising in a variety of lying postures. Stiffness was measured during hip flexion, extension, abduction and adduction. Stiffness data was obtained during the first degree and at ROM, and at the highest common angle achieved by participants in each posture Spinal curvature and other postural components were measured using a motion tracking device. Spearman rank coefficients were determined to assess any correlations between passive stiffness, range of motion, spinal curvature and other postural components.

RESULTS

Consistent relationships were found between maximum range of motion and hip stiffness at the common angles (P < 0.01), but not at maximum stiffness (P > 0.05). Consistent correlations were found between abductor stiffness and Q-angle (P < 0.05). Hip extensor range of motion correlated with lumbar lordosis (r = -0.472, P = 0.036). Other correlations were reported, but typically lacked consistency between left and right sides. Spinal curvature did not correlate with hip stiffness in frontal or sagittal planes (P > 0.05).

SIGNIFICANCE

Significant correlations were few compared with where correlations lacked statistical significance. This study demonstrates that overly simplistic assumptions about spinal posture and hip stiffness cannot be supported. Hip muscle stiffness should only be targeted in treatments where testing has demonstrated a direct need, and not assumed based upon postural assessment alone.

Effect of 4 Weeks of Anti-Gravity Treadmill Training on Isokinetic Muscle Strength and Muscle Activity in Adults Patients with a Femoral Fracture: A Randomized Controlled Trial

This study aimed to identify the effect of anti-gravity treadmill training on isokinetic lower-limb muscle strength and muscle activities in patients surgically treated for a hip fracture. A total of 34 participants were randomly assigned into two groups: anti-gravity treadmill training group (n = 17) and control group (n = 17). The isokinetic muscle strength and endurance of hip flexor and extensor and the activities of the vastus lateralis (VL), vastus medialis (VM), gluteus maximus (GM), and gluteus medialis (Gm) muscles were measured before and after 4 weeks of the interventions. Significant improvements were observed in isokinetic muscle strength and endurance of hip flexors and extensors in both groups (p < 0.05); however, no significant differences were observed between the groups (p > 0.05) except for muscle strength of the hip extensor (d = 0.78, p = 0029). Statistically significant increases in the muscle activity of VL, VM, GM, and Gm were found before and after the intervention (p < 0.05), and significant differences in muscle activities of GM (d = 2.64, p < 0.001) and Gm (d = 2.59, p < 0.001) were observed between the groups. Our results indicate that both groups showed improvement in muscle strength, endurance, and activities after the intervention. Additionally, anti-gravity treadmill training improved significantly more muscle strength at 60°/s of the hip extensor and gluteus muscle activities than conventional therapy, which may be appropriate for patients with hip fracture surgery.

Passive elastic contribution of hip extensors to joint moments during walking in people with low back pain

BACKGROUND

It has been found that alterations in passive muscle properties may be associated with low back pain, and these may be responsible for the altered gait parameters often observed in subjects with back pain. The purpose of the present study was to assess total hip and passive hip extensor moments in people with or without low back pain during the hip flexion component of walking.

METHODS

52 subjects volunteered for this study (low back pain group, n = 25 (male n = 13, female n = 12), control group, n = 27 (male n = 15, female n = 12)). Passive hip moments were calculated using an adapted force transducer during supine testing. A biomechanical model and predictive equation were used to calculate passive hip moments during walking. Total hip moments were calculated with the use of a 9 camera, 3-D motion-capture system.

FINDINGS

Independent samples t-tests demonstrated no significant differences between groups for gait parameters or hip or knee angles. Results of the ANOVAs demonstrated significant differences in passive hip flexor moments during the second half of hip flexion (P < 0.05).There were also significant differences in hip power and work done during peaks of power absorption and the second peak of power generation (P < 0.05).

INTERPRETATION

The present data demonstrates that subjects with low back pain have altered passive hip extensor and total power and work done during walking compared with healthy controls. Biomechanical models should include individual measurements of passive joint moments.

Contribution of passive actions to the lower limb joint moments and powers during gait: A comparison of models

The lower limb passive actions representing the actions of all the passive periarticular structures have been shown to have a significant contribution to the power generation and absorption during gait. However, the respective magnitude of its different components was not established, although models of ligament moment were implemented in some musculoskeletal models. These ligament moments have shown to have an influence on the musculo-tendon forces and contact forces but the models used were never specifically evaluated, that is, compared to the passive and net joint moments. Two models of passive joint moments and three models of ligament moments were selected from the literature. Ten subjects (23–29 years old, 79.8 ± 9.5 kg, 1.85 ± 0.06 m) participated in the study. Each subject performed three gait cycles in a gait laboratory to acquire the kinematics and ground reaction forces and to compute the ligament, passive and net moments of the right lower limb joints. The contributions of the passive joint moments to the net joint moments were in accordance with the literature, although time shifts appeared for peaks in the hip and knee powers. Two of the models of ligament moments seemed, in fact, to represent the passive joint moments as their contributions were very similar while the third model of ligament moments seemed to represent only penalty-based joint limits. As a conclusion, this study showed that the models of ligament moments existing in the literature do not seem reliable. This study also demonstrated that the use of non-subject-specific models of the passive joint moments could be a valid approach for healthy subjects.

Lower hamstring extensibility in men compared to women is explained by differences in stretch tolerance

BACKGROUND

This study examined whether passive hamstring tissue stiffness and/or stretch tolerance explain the relationship between sex and hamstring extensibility.

METHODS

Ninety healthy participants, 45 men and 45 women (mean ± SD; age 24.6 ± 5.9 years, height 1.72 ± 0.09 m, weight 74.6 ± 14.1 kg) volunteered for this study. The instrumented straight leg raise was used to determine hamstring extensibility and allow measurement of stiffness and stretch tolerance (visual analog pain score, VAS).

RESULTS

Hamstring extensibility was 9.9° greater in women compared to men (p = 0.003). VAS scores were 16 mm lower in women (p = 0.001). Maximal stiffness (maximal applied torque) was not different between men and women (p = 0.42). Passive stiffness (slope from 20-50° hip flexion) was 0.09 Nm.°(-1) lower in women (p = 0.025). For women, linear and stepwise regression showed that no predictor variables were associated with hamstring extensibility (adjusted r(2) = -0.03, p = 0.61). For men, 44% of the variance in hamstring extensibility was explained by VAS and maximal applied torque (adjusted r(2) = 0.44, p < 0.001), with 41% of the model accounted for by the relationship between higher VAS scores and lower extensibility (standardized β coefficient = -0.64, p < 0.001).

CONCLUSIONS

The results of this study suggest that stretch tolerance and not passive stiffness explains hamstring extensibility, but this relationship is only manifest in men.

FEASIBILITY OF ESTIMATING JOINT MOMENTS DURING GAIT WITH ONLY KINEMATIC DATA

A preliminary model is presented for estimating floor reaction forces during human walking based only on kinematic data. Such a model would be useful for supplementing purely qualitative gait analysis performed in clinics where force plates would be an unaffordable luxury, but not for situations in which quantitative data would be used in making such decisions as how to perform an orthopedic surgery. In this model, the vertical components of floor reaction forces are determined by conventional double differentiation of kinematic data, but the horizontal (fore-aft) components are based instead on constraints in which the floor reaction forces are characterized as acting through the center of mass of the upper body. To assess the accuracy of our calculations, we gathered data of gait by a healthy 22-year-old woman using a motion analysis system with force plates. Pathological gait data were also examined. Joint moments were computed from both force plate data and from our estimates of floor reaction forces. Prediction of vertical force showed higher reliability than prediction of fore-aft force. Joint moments from kinematics were successfully calculated in normal gait, but not in pathological gait, especially at the hip joint. The proposed approach may have some merit for performing a gait analysis even when no force plate is present, but the inaccuracy increases in the case of a subject whose upper body sways during gait.

The ability of a sustained within-session finding of pain reduction during traction to dictate improved outcomes from a manual therapy approach on patients with osteoarthritis of the hip

OBJECTIVES

THE OBJECTIVES OF THIS STUDY WERE TO: (1) determine the association of a within-session finding after traction of the hip with self-report of well-being, pain, and self-report of function at 9 weeks; and (2) to determine if the interactions between the within-session finding and the outcome measure are different between groups of patients with hip OA who receive and who do not receive manual therapy.

METHODS

Data were retrospectively analysed in 70 subjects who were part of a randomized control trial. Correlation analyses of within-session findings from the initial visit after traction of a concordantly painful hip were compared to self-report measures for function, pain, and well-being at 9 weeks. A comparison of slope coefficients between manual therapy and non-manual therapy groups was performed to determine the interactive aspects of the within-session finding.

RESULTS

Although the correlations for the manual therapy group were higher than for the supervised neglect group, none of the correlational analyses for both groups was strong or significant. Significant differences in the slope coefficients for well-being and pain were found, suggesting that the interactions between the within-session findings and the targeted outcomes were different in the manual therapy group versus supervised neglect group.

DISCUSSION

These findings suggest that within-session findings during the initial evaluation are not strongly related to a positive outcome after manual therapy, although the interaction of the finding of a within-session change and the use of manual therapy is more compelling than the finding in a sample of patients who did not receive manual therapy.

Real-time measurement of patellofemoral kinematics in asymptomatic subjects

The aims of this study were to determine whether patellofemoral kinematics in the anteroposterior (AP), mediolateral (ML) and proximal-distal (PD) directions could be measured in real time with high repeatability using a three-dimensional magnetic tracking system, and to evaluate the symmetry between sides. Data was collected from both knees of 40 asymptomatic subjects while performing knee flexion from 0 degrees to 60 degrees . Measurement of patellar displacement along the three anatomical axes (AP, ML, and PD) with respect to an anatomical coordinate system was collected using the Fastrak system. Data from three trials of each knee was plotted against knee angle and the repeatability of the data determined by examining the similarity of the movement-time curves. Symmetry was determined for maximal displacement and kinematic pattern, and a paired t-test performed to evaluate differences between sides. The data was found to be highly repeatable with mean r values for the three directions over 0.85 for both sides. The pattern of patellar displacement and maximal displacement was comparable to that reported in the literature. Results of paired t-test revealed no significant differences between the knees when comparing maximal displacement in any direction (p>0.05). Overall, there was a highly symmetrical kinematic pattern for ML and PD displacement and a small degree of asymmetry for AP displacement. However, wide variations among the subjects were noted between the left and right patellae in all directions. The results of this study have demonstrated that the use of magnetic tracking sensors provides repeatable and relevant three-dimensional kinematic data of in vivo patella tracking from 0 degrees to 60 degrees of knee flexion.

Modelling and simulation of the intervertebral movements of the lumbar spine using an inverse kinematic algorithm

An inverse kinematic model is presented that was employed to determine the optimum intervertebral joint configuration for a given forward-bending posture of the human trunk. The lumbar spine was modelled as an open-end, kinematic chain of five links that represented the five vertebrae (L 1-L5). An optimisation equation with physiological constraints was employed to determine the intervertebral joint configuration. Intervertebral movements were measured from sagittal X-ray films of 22 subjects. The mean difference between the X-ray measurements of intervertebral rotations in the sagittal plane and the values predicted by the kinematic model was less than 1.6 degrees. Pearson product-moment correlation R was used to measure the relationship between the measured and predicted values. The R-values were found to be high, ranging from 0.83 to 0.97, for prediction of intervertebral rotation, but poor for intervertebral translation (R= 0.08-0.67). It is concluded that the inverse kinematic model will be clinically useful for predicting intervertebral rotation when X-ray or invasive measurements are undesirable. It will also be useful to biomechanical modelling, which requires accurate kinematic information as model input data.

Mechanics and control of the flat versus normal foot during the stance phase of walking

OBJECTIVE

To compare walking stance phase rearfoot and forefoot motion, ankle joint moments and extrinsic foot muscle EMG profiles between normal and pes planus feet.

DESIGN

A cross-sectional comparative study.

BACKGROUND

Musculoskeletal conditions are often attributed to pes planus, in which motion is assumed to be excessive and the muscle control inadequate. However, many of the speculated differences in mechanics and control between the normal and the pes planus foot have not been quantified.

METHODS

Kinematic and kinetic data were obtained from video recordings of skin surface markers and a force plate, and EMG was recorded with surface electrodes. Analysis of variance was carried out to compare the group profiles.

RESULTS

In the pes planus group: the forefoot was less adducted (P < .05) at toe-off, and total transverse plane range of motion, at 8 degrees versus 10 degrees, was less (P < .01); the peak plantarflexor ankle moment at push-off was greater (P < .05); the invertor moment was greater at foot flat (P < .05); for the EMG profiles, activity early in stance, relative to the mean stance phase activity was higher (P < .01) in tibialis anterior and lower (P < .05) in the peronei, soleus and medial and lateral gastrocnemius.

CONCLUSIONS

Despite reaching statistical significance, the group differences were small for the task of laboratory walking at a natural pace. The main implications of the differences were for restraint of motion. The expectations of excessive motion and muscle effort in the pes planus group were therefore not substantiated.

RELEVANCE

Symptomatic pes planus subjects did not reveal the expected biomechanical differences from normal subjects. The underlying causes of symptoms were not identifiable.

Differential Diagnosis and Management of Spinal Nerve Root-related Pain

Pain originating from spinal nerve roots demonstrates multiple pathogeneses. Distinctions in the patho-anatomy, biomechanics, and pathophysiology of spinal nerve roots contribute to pathology, diagnosis, and management of root-related pain. Root-related pain can emerge from the tension events in the dura mater and nerve tissue associated with primary disc related disorders. Conversely, secondary disc-related degeneration can produce compression on the nerve roots. This compression can result in chemical and mechanical consequences imposed on the nervous tissue within the spinal canal, lateral recess, intervertebral foramina, and extraforminal regions. Differences in root-related pathology can be observed between lumbar, thoracic, and cervical spinal levels, meriting the implementation of different diagnostic tools and management strategies.

Interpretation of Ankle Joint Moments during the Stance Phase of Walking: A Comparison of Two Orthogonal Axes Systems

Three-dimensional ankle joint moments were calculated in two separate coordinate systems, from 18 healthy men during the stance phase of walking, and were then compared. The objective was to determine the extent of differences in the calculated moments between these two commonly used systems and their impact on interpretation. Video motion data were obtained using skin surface markers, and ground reaction force data were recorded from a force platform. Moments acting on the foot were calculated about three orthogonal axes, in a global coordinate system (GCS) and also in a segmental coordinate system (SCS). No differences were found for the sagittal moments. However, compared to the SCS, the GCS significantly (p < .001) overestimated the predominant invertor moment at midstance and until after heel rise. It also significantly (p < .05) underestimated the late stance evertor moment. This frontal plane discrepancy was attributed to sensitivity of the GCS to the degree of abduction of the foot. For the transverse plane, the abductor moment peaked earlier (p < .01) and was relatively smaller (p < .01) in the GCS. Variability in the transverse plane was greater for the SCS, and attributed to its sensitivity to the degree of rearfoot inversion. We conclude that the two coordinate systems result in different calculations of nonsagittal moments at the ankle joint during walking. We propose that the body-based SCS provides a more meaningful interpretation of function than the GCS and would be the preferred method in clinical research, for example where there is marked abduction of the foot.