Residual gait deviations in children treated by medial open reduction for developmental dysplasia of the hip at long-term follow-up: a comparison with healthy controls.

PURPOSE: This study aimed to analyze and compare gait patterns and deviations at long-term follow-up in children who received medial open reduction (MOR) before 18 months for unilateral or bilateral hip developmental dysplasia (DDH). METHODS: A retrospective chart review was conducted on children who underwent MOR. The study population was divided into two groups: the unilateral group, including unilateral (five children with unilateral) and bilateral (five children with bilateral DDH). Ten healthy children were recruited for the control group. Spatiotemporal, kinematic, stiff-knee gait (SKG), and kinetic gait characteristics were analyzed. RESULTS: Stance time was significantly shorter in both the unilateral (median [IQR]; 590 ms, [560.0-612.5] and bilateral (575 ms, [550-637.5]) groups than in the control group (650, [602.5-677.5]) (p < 0.001), whereas swing time did not differ substantially (p = 0.065) There was no considerable difference in the mean knee flexion at swing between the unilateral (31.6°, [30-36]) and control (30.11°, [27.8-33.6] groups (p > 0.05), but the bilateral group (28.5°, [24.9-32.1]) showed the lower values than the other groups (p < 0.001 for bilateral vs unilateral group; p = 0.008 bilateral vs unilateral group). All the SKG parameters significantly differed among the groups in multi-group comparisons (p < 0.001 for each parameter). Three children had borderline SKG, and two had not-stiff limbs in the unilateral group. In the bilateral group, four children had stiff limbs, and one had borderline SKG. Most kinetic gait parameters were not statistically different between groups (p > 0.05). CONCLUSION: This study has revealed notable deviations in gait patterns of children with DDH treated by MOR at long-term follow-up compared to healthy children's gait. MOR could negatively affect pelvic motion during gait due to impaired functions of the iliopsoas and adductor muscles, and SKG can be encountered secondary to iliopsoas weakness.

Functional Bandaging in Children with Idiopathic Toe-Walking.

BACKGROUND: Idiopathic toe-walking (ITW) is a persistent gait pattern with no known etiology characterized as premature heel rise or no heel contact. We investigated the effects of functional bandaging in children with ITW on heel contact during stance phase and on gait quality. METHODS: Nineteen children aged 4 to 16 years with ITW and ten age-matched healthy children were included in the study. Elastic adhesive bandages were applied to children with ITW to assist with dorsiflexion. Before bandaging (T0) and immediately (T1) and 1 week (T2) after initial bandaging, the initial contact, loading response, and midstance subphases of gait were analyzed using light pressure sensors and the Edinburgh Visual Gait Score (EVGS). Ten age-matched children with typical gait participated for comparison in T0. The data were analyzed with Friedman and Wilcoxon signed rank tests for within-group comparisons and Mann-Whitney U tests for between-group comparisons. RESULTS: In T0, for the ITW group, no heel contact was observed during stance. In T1, all of the participants achieved heel contact at initial contact and loading response and 56.8% at midstance. In T2, all of the heels continued contact at initial contact and loading response and 54.3% at midstance. The EVGS significantly improved. The Friedman test showed that there were noteworthy improvements between T0-T1 and T0-T2 in video-based observational gait analysis and EVGSs (P < .001), although no difference was found between T1-T2 in video-based observational gait analysis (P = .913) and EVGSs (P = .450). CONCLUSIONS: In children with ITW, dorsiflexion assistive functional bandaging was an effective tool to help achieve heel contact on the ground and improve walking quality for a short period after application. Further studies with longer follow-up and larger sample sizes are required to confirm the long-term therapeutic effects of this promising functional bandaging.

Intraoperative testing of passive and active state mechanics of spastic semitendinosus in conditions involving intermuscular mechanical interactions and gait relevant joint positions.

In cerebral palsy (CP) patients suffering pathological knee joint motion, spastic muscle's passive state forces have not been quantified intraoperatively. Besides, assessment of spastic muscle's active state forces in conditions involving intermuscular mechanical interactions and gait relevant joint positions is lacking. Therefore, the source of flexor forces limiting joint motion remains unclear. The aim was to test the following hypotheses: (i) in both passive and active states, spastic semitendinosus (ST) per se shows its highest forces within gait relevant knee angle (KA) range and (ii) due to intermuscular mechanical interactions, the active state forces elevate. Isometric forces (seven children with CP, GMFCS-II) were measured during surgery over a range of KA from flexion to full extension, at hip angle (HA) = 45° and 20°, in four conditions: (I) passive state, (II) individual stimulation of the ST, simultaneous stimulation of the ST (III) with its synergists, and (IV) also with an antagonist. Gait analyses: intraoperative data for KA = 17-61° (HA = 45°) and KA = 0-33° (HA = 20°) represent the loading response and terminal swing, and mid/terminal stance phases of gait, respectively. Intraoperative tests: Passive forces maximally approximated half of peak force in condition II (HA = 45°). Added muscle activations did increase muscle forces significantly (HA = 45°: on average by 42.0% and 72.5%; HA = 20°: maximally by 131.8% and 123.7%, respectively in conditions III and IV, p < 0.01). In conclusion, intermuscular mechanical interactions yield elevated active state forces, which are well above passive state forces. This indicates that intermuscular mechanical interactions may be a source of high flexor forces in CP.

Intraoperative experiments combined with gait analyses indicate that active state rather than passive dominates the spastic gracilis muscle's joint movement limiting effect in cerebral palsy.

BACKGROUND: In cerebral palsy, spastic muscle's passive forces are considered to be high but have not been assessed directly. Although activated spastic muscle's force-joint angle relations were studied, this was independent of gait relevant joint positions. The aim was to test the following hypotheses intraoperatively: (i) spastic gracilis passive forces are high even in flexed knee positions, (ii) its active state forces attain high amplitudes within the gait relevant knee angle range, and (iii) increase with added activations of other muscles. METHODS: Isometric forces (seven children with cerebral palsy, gross motor function classification score = II) were measured during surgery from knee flexion to full extension, at hip angles of 45° and 20° and in four conditions: (I) passive state, after gracilis was stimulated (II) alone, (III) simultaneously with its synergists, and (IV) also with an antagonist. FINDINGS: Directly measured peak passive force of spastic gracilis was only a certain fraction of the peak active state forces (maximally 26%) measured in condition II. Conditions III and IV caused gracilis forces to increase (for hip angle = 45°, by 32.8% and 71.9%, and for hip angle = 20°, by 24.5% and 45.1%, respectively). Gait analyses indicated that intraoperative data for knee angles 61-17° and 33-0° (for hip angles 45° and 20°, respectively) are particularly relevant, where active state force approximates its peak values. INTERPRETATION: Active state muscular mechanics, rather than passive, of spastic gracilis present a capacity to limit joint movement. The findings can be highly relevant for diagnosis and orthopaedic surgery in individuals with cerebral palsy.

Does clinically measured ankle plantar flexor muscle strength or weakness correlate with walking performance in healthy individuals?

OBJECTIVE: Muscle strength is usually measured using isometric hand-held dynamometers (HHDs) in the clinic. However, during functional activities, the muscle acts more dynamically. The aim of this study was to investigate the relation between clinically measured plantar flexor (PF) muscle strength (PFMS) and laboratory measurements of peak ankle plantar flexion power generation (APFPG), peak ankle moment (PAM), peak plantar flexion velocity (PFV) and mean gait velocity in healthy participants. METHODS: The maximum PFMS on non-dominant sides in 18 able-bodied persons 23.88 (SD 3.55 years) was measured before (Pre-S) and after a stretching (Post-S) procedure (135 sec. × 13 rep. with 5 sec. rest) by using a HHD. The stretching procedure was used to generate temporary PF muscle weakness. Gait analysis was carried out for Pre-S and Post-S conditions. Normalized (by weight and height) and non-normalized HHD scores and differences for both conditions were correlated by Pearson correlation coefficient calculations (p< 0.05). RESULTS: Reduced PFMS (%23, p< 0.001) in Post-S, according to the HHD scores, has only a weak correlation with APFPG (r> 0.3, p< 0.5). Gait velocity was found to be strongly correlated with APFPG only in the Post-S condition (r= 0.68, p< 0.002). HHD scores and PAM were moderately correlated with the non-normalized Post-S condition (r= 0.44, p= 0.70) and strongly correlated with the non-normalized Pre-S condition (r= 0.62, p< 0.01). DISCUSSION: HHD scores of plantar flexor muscles give very limited information about the PF performance during walking in healthy individuals. Simple normalization did not improve the relations. Clinically measured isometric muscle strength and muscle weakness have only moderate strengths for establishing a treatment protocol and for predicting performance during walking in neurologically intact individuals.

Weakening iliopsoas muscle in healthy adults may induce stiff knee pattern.

OBJECTIVE: The goal of the present study was to investigate the relationship between iliopsoas muscle group weakness and related hip joint velocity reduction and stiff-knee gait (SKG) during walking in healthy individuals. METHODS: A load of 5% of each individual's body weight was placed on non-dominant thigh of 15 neurologically intact, able-bodied participants (average age: 22.4 ± 0.81 years). For 33 min (135 s × 13 repetitions × 5 s rest), a passive stretch (PS) was applied with the load in place until hip flexor muscle strength dropped from 5/5 to 3+/5 according to manual muscle test. All participants underwent gait analysis before and after PS to compare sagittal plane hip, knee, and ankle kinematics and kinetics and temporo-spatial parameters. Paired t-test was used to compare pre- and post-stretch findings and Pearson correlation coefficient (r) was calculated to determine strength of correlation between SKG parameters and gait parameters of interest (p < 0.05). RESULTS: Reduced hip flexion velocity (mean: 21.5%; p = 0.005) was a contributor to SKG, decreasing peak knee flexion (PKF) (-20%; p = 0.0008), total knee range (-18.9%; p = 0.003), and range of knee flexion between toe-off and PKF (-26.7%; p = 0.001), and shortening duration between toe-off to PKF (-16.3%; p = 0.0005). CONCLUSION: These findings verify that any treatment protocol that slows hip flexion during gait by weakening iliopsoas muscle may have great potential to produce SKG pattern combined with reduced gait velocity.

Plantar flexor muscle weakness may cause stiff-knee gait.

AIM: The iterative simulation studies proclaim that plantar flexor (PF) muscle weakness is one of the contributors of stiff knee gait (SKG), although, whether isolated PF weakness generates SKG has not been validated in able-bodied people or individuals with neuromuscular disorders. The aim of the study was to investigate the effects of isolated PF muscle weakness on knee flexion velocity and SKG in healthy individuals. METHOD: Twenty able-bodied young adults (23±3 years) participated in this study. Passive stretch (PS) protocol was applied until the PF muscle strength dropped 33.1% according to the hand-held dynamometric measurement. Seven additional age-matched able-bodies were compared with participants' to discriminate the influence of slow-walking. All participants underwent 3D gait analysis before and after the PS. Peak knee flexion angle, range of knee flexion between toe-off and peak knee flexion, total range of knee-flexion, and time of peak knee flexion in swing were selected to describe SKG pattern. RESULTS: After PS, the reduction of plantar flexor muscle strength (33.14%) caused knee flexion velocity drop at toe-off (p=0.008) and developed SKG pattern by decreasing peak knee flexion (p=0.0001), range of knee flexion in early swing (p=0.006), and total knee flexion range (p=0.002). These parameters were significantly correlated with decreased PF velocity at toe-off (p=0.015, p=0.0001, p=0.005, respectively). The time of peak knee flexion was not significantly different between before and after stretch conditions (p=0.130). CONCLUSIONS: These findings verified that plantar flexor weakness cause SKG pattern by completing three of SKG parameters. Any treatment protocol that weakens the plantar flexor muscle might impact the SKG pattern.

Contributors of stiff knee gait pattern for able bodies: Hip and knee velocity reduction and tiptoe gait.

UNLABELLED: Stiff-knee gait (SKG) is commonly encountered in clinic; many other gait abnormalities are seen together with this pathology. Simulation studies revealed that diminished knee flexion (KF) velocity and increased knee extension moments are strongly related with SKG. This study aimed to determine whether tiptoe walking and hip-knee flexion velocity reduction causes SKG pattern in healthy participants. METHODS: Fourteen able-bodied adults' (Av. age: 23.0±2.4) heel-toe (N), tiptoe (T), and walking with 5% body weight on both shanks (W) were analyzed using 3D gait analysis by controlling cadence (90step/min). Repeated measures analysis of variance was used followed by Bonferroni correction (p<0.05). RESULTS: Walking velocity and cadence were similar for all conditions (p>0.1). Maximum hip flexion velocity was reduced (15%) significantly as well as the KF velocity (10%) in the W condition. The peak knee flexion (PKF) (8.3% for T, 8.6% for W) and total knee range (10.9% for T, 13% for W) were reduced for both conditions (p<0.05). The knee range in early swing and the duration between toe-off and PKF were reduced only in the weighted-leg condition (p<0.05). CONCLUSIONS: Slow hip and knee flexion diminished all SKG parameters except timing of PKF. Tiptoe gait itself generated a borderline SKG pattern by reducing the PKF and total knee range. By considering that tiptoe gait and SKG commonly seen together, some of the SKG contributors can be treated by normalizing the ankle motion in the stance and increasing the hip-knee flexion velocity by rigorously planned muscle lengthening procedures and effective strengthening exercises.

Effects of unilateral backpack carriage on biomechanics of gait in adolescents: a kinematic analysis.

OBJECTIVE: The aim of this study was to analyze the biomechanical alterations during unilateral backpack carriage in adolescents and to compare the kinematic parameters of the loaded and unloaded sides. METHODS: Twenty adolescents (mean age: 13 ± 1.2 years) were assessed during walking with no backpack and with a backpack on one shoulder. The kinematic parameters of a gait at a self-selected speed were analyzed using motion analysis. Specific kinematic peak points were compared between asymmetric walking; unloaded, loaded side and mean of unloaded walking. RESULTS: Peak ankle dorsal flexion, mean knee varum angle, peak value of hip extension and range of pelvic rotation decreased; and knee flexion at initial contact, hip adduction angle, mean pelvic anterior tilt and mean pelvic obliquity increased on the loaded side relative to the unloaded side and unloaded walking. Decreased maximum hip extension during late stance, increased hip adduction, elevated pelvis and increased anterior pelvic tilt were seen on the loaded side and the pelvis was lowered, ankle dorsal flexion increased and the hip was abducted on the unloaded side as a counter effect. CONCLUSION: Both the unloaded and loaded sides were affected by asymmetrical backpack carriage. The biomechanical alterations seen in asymmetrical backpack carriage may put some extra load on the lumbar vertebral joints and altered frontal knee biomechanics contribute to low back pain and pathologies in the knee joint.

[Treatment approaches to flexion contractures of the knee]. / Diz fleksiyon kontraktüründe tedavi yaklasimlari.

The knee is the most affected joint in children with cerebral palsy. Flexion contracture of the knee is the cause of crouch gait pattern, instability in stance phase of gait, and difficulties during standing and sitting, and for daily living activities. It may also cause patella alta, degeneration of the patellofemoral joint, and stress fractures of the patella and tibial tubercle in young adults. Children with cerebral palsy may even give up walking due to its high energy demand in the adult period. The purpose of this article is to review the causes of the knee flexion contractures, clinical and radiological evaluations, and treatment principles in children with cerebral palsy. The biomechanical reasons of knee flexion deformity are discussed in detail in the light of previous studies and gait analysis data.

Effects of back loading on the biomechanics of sit-to-stand motion in healthy children.

The goal of the present study was to determine the thus far unstudied effects of back loading on the kinematics and kinetics of sit-to-stand (STS) motion in healthy children. Fifteen children (8 boys, 7 girls, mean age 9.6 years, SD 1.2 years) were tested with no back load and with a back load of 10% and 20% of body weight, respectively. A motion analysis system was used with six infrared cameras and two force plates. Total STS duration did not change; however, differential effects were shown for the durations of its phases. Back loading increased ankle dorsiflexion yielding a greater maximal dorsiflexion angle. Effects on the knee angle were limited except for a significant decrease in final knee flexion. Initial and maximal hip flexion increased but final hip angle did not change. Initial backward pelvic tilt decreased and a shift to forward pelvic tilt occurred at an earlier stage of STS motion. Back loading affected trunk motion: maximal and final forward shoulder tilt increased. Maximal ankle and knee moments and powers increased; however, hip joint kinetics was not affected significantly. Therefore, while maintaining the general pattern of STS motion, participants showed selectively significant adjustments to back loading during its different phases. The main kinematic adjustments were increased trunk flexion and greater ankle dorsiflexion, while the major kinetic adjustment was increased knee extension moment. Increased back loading yielded more pronounced effects, primarily in the ankle. In sum, back loading substantially affected the biomechanics of STS motion even for the lower load level studied. This finding may be of clinical relevance for musculoskeletal disorders, but this needs to be examined.