Joint angular velocity in spastic gait and the influence of muscle-tendon lengthening

BACKGROUND: Joint angular velocity (the rate of flexion and extension of a joint) is related to the dynamics of muscle activation and force generation during walking. Therefore, the goal of this research was to examine the joint angular velocity in normal and spastic gait and changes resulting from muscle-tendon lengthening (recession and tenotomy) in patients who have spastic cerebral palsy. METHODS: The gait patterns of forty patients who had been diagnosed with spastic cerebral palsy (mean age, 8.3 years; range, 3.7 to 14.8 years) and of seventy-three age-matched, normally developing subjects were evaluated with three-dimensional motion analysis and electromyography. The patients who had cerebral palsy were evaluated before muscle-tendon lengthening and nine months after treatment. RESULTS: The gait patterns of the patients who had cerebral palsy were characterized by increased flexion of the knee in the stance phase, premature plantar flexion of the ankle, and reduced joint angular velocities compared with the patterns of the normally developing subjects. Even though muscle-tendon lengthening altered sagittal joint angles in gait, the joint angular velocities were generally unchanged at the hip and knee. Only the ankle demonstrated modified angular velocities, including reduced dorsiflexion velocity at foot-strike and improved dorsiflexion velocity through mid-stance, after treatment. Electromyographic changes included reduced amplitude of the gastrocnemius-soleus during the loading phase and decreased knee coactivity (the ratio of quadriceps and hamstring activation) at toe-off. Principal component analyses showed that, compared with joint-angle data, joint angular velocity was better able to discriminate between the gait patterns of the normal and cerebral palsy groups. CONCLUSIONS: This study showed that muscle-tendon lengthening corrects biomechanical alignment as reflected by changes in sagittal joint angles. However, joint angular velocity and electromyographic data suggest that the underlying neural input remains largely unchanged at the hip and knee. Conversely, electromyographic changes and changes in velocity in the ankle indicate that the activation pattern of the gastrocnemius-soleus complex in response to stretch was altered by recession of the complex.     

Kinematic and kinetic outcomes after identical multilevel soft tissue surgery in children with cerebral palsy

This study evaluates the outcomes of multilevel soft tissue surgery in 31 ambulatory children (n = 39 sides) with cerebral palsy. All children had undergone rectus femoris transfer, hamstring lengthening, and gastrosoleus lengthening for the purpose of correcting sagittal plane abnormalities. There were no simultaneous bony surgeries. Preoperative and postoperative evaluation consisted of clinical assessment and gait analysis, including 3-dimensional kinematics and kinetics. Results demonstrated improvements in knee and ankle function. At the knee, there was a decrease in mean flexion at initial contact (from 31 degrees [SD, +/-8 degrees] to 21 degrees [SD, +/-10 degrees]) and in stance (mean stance, 22 degrees [SD, +/-12 degrees] to 16 degrees [SD, +/-11 degrees]) associated with a decreased mean internal extensor moment in stance (from 0.09 Nm/kg [SD, +/-0.24 Nm/kg] to -0.03 [SD, +/-0.22 Nm/kg]). At the same time, knee flexion was preserved in swing and occurred earlier. At the ankle, mean dorsiflexion improved at the time of examination (from 8 degrees [SD, +/-9 degrees] to 14 degrees [SD, +/-11 degrees] with the knee in extension), in terminal stance (peak from 7 degrees [SD, +/-9 degrees] to 12 degrees [SD, +/-8 degrees]), and in swing. Peak ankle power generation in stance was preserved and shifted later in stance toward push-off, with no functional weakening of the ankle plantar flexors. A longer-term assessment of a subset of patients with a second postoperative gait analysis at a mean of 4 years after surgery showed that gains measured at 1 year were maintained during the longer term. A subgroup demonstrating a jump knee gait pattern (as defined by excessive knee flexion at initial contact followed by rapid knee extension to full knee extension in midstance) had a tendency to go into knee hyperextension in stance with resultant net knee flexor moment after surgery. This raises concern about the indications for hamstring lengthening in this patient group.     

A functional electrical stimulation system improves knee control in crouch gait

BackgroundCrouch gait is a major sagittal plane deviation in children diagnosed with cerebral palsy (CP). It is defined as a combination of excessive ankle dorsiflexion and knee and hip flexion throughout the stance phase. To the best of our knowledge, functional electrical stimulation (FES) has not been used to decrease the severity of crouch gait in CP subjects and assist in achieving lower limb extension.PurposeTo evaluate the short- and long-term effects of FES to the quadriceps muscles in preventing crouch gait and achieving ankle plantar flexion, knee and hip extension at the stance phase.MethodsAn 18-year-old boy diagnosed with CP diplegia [Gross Motor Function Classification System (GMFCS) level II] was evaluated. The NESS L300^® Plus neuroprosthesis system provided electrical stimulation of the quadriceps muscle. A three-dimensional gait analysis was performed using an eight-camera system measuring gait kinematics and spatiotemporal parameters while the subject walked shod only, with ground reaction ankle foot orthotics (GRAFOs) and using an FES device.ResultsWalking with the FES device showed an increase in the patient’s knee extension at midstance and increased knee maximal extension at the stance phase. In addition, the patient was able to ascend and descend stairs with a “step-through” pattern immediately after adjusting the FES device.ConclusionsThis report suggests that FES to the quadriceps muscles may affect knee extension at stance and decrease crouch gait, depending on the adequate passive range of motion of the hip, knee extension, and plantar flexion. Further studies are needed in order to validate these results.     

Hamstrings and psoas lengths during normal and crouch gait: Implications for muscle-tendon surgery

Crouch gait, one of the most common movement abnormalities among children with cerebral palsy, is characterized by persistent flexion of the knee during the stance phase. Short hamstrings are thought to be the cause of crouch gait; thus, crouch gait is often treated by surgical lengthening of the hamstrings. In this study, a graphics-based model of the lower extremity was used in conjunction with three-dimensional kinematic data obtained from gait analysis to estimate the lengths of the hamstrings and psoas muscles during normal and crouch gaits. Only three of 14 subjects with crouch gait (four of 20 limbs with knee flexion of 20° or more through stance) had hamstrings that were shorter than normal by more than 1 SD during walking. Most (80%) of the subjects with crouch gait had hamstrings of normal length or longer, despite persistent knee flexion during stance. This occurred because the excessive knee flexion was typically accompanied by excessive hip flexion throughout the gait cycle. All of the subjects with crouch gait had a psoas that was shorter than normal by more than 1 SD during walking. These results emphasize the need to consider the geometry and kinematics of multiple joints before performing surgical procedures aimed at correcting crouch gait.     

Adult-onset hemiplegia: changes in gait after muscle-balancing procedures to correct the equinus deformity

Fifty-four adult patients with acquired spastic equinus and equinovarus deformity were treated with lengthening of the Achilles tendon, lateral transfer of the anterior tibial tendon, and appropriate muscle releases. All patients had preoperative dynamic electromyography and electrogoniometry performed in order to assist in planning the surgical procedures and to provide a baseline assessment of the dynamic deformities. Preoperatively, the stance and double-support phases of gait were prolonged. Throughout the stance phase, the gait of these patients was characterized by equinus deformity of the ankle, decreased flexion of the knee (hyperextension in the most severely involved patients), and increased flexion of the hip (which also varied with the severity of the equinus deformity of the ankle and hyperextension of the knee). In all patients, the operation was performed at least one year after onset of the hemiplegia. Clinical follow-up at an average of thirty months (range, twenty-four to sixty-two months) showed that the equinus deformity was corrected in all patients and that 59 per cent of them were brace-free. Two patients had a superficial infection that healed uneventfully, and two had pull-out of the tendon that required reoperation. Postoperative analyses of gait, performed at least one year after surgery for twenty-seven of the patients, showed that the stance and double-support phases of gait (which had been prolonged before surgery) approached the findings in normal control subjects.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of hamstring transfer with hamstring lengthening in ambulatory children with cerebral palsy: further follow-up

Background

Overactivity or contractures of the hamstring muscles in ambulatory children with cerebral palsy (CP) can lead to either a jump gait (knee flexion associated with ankle plantar flexion) or a crouch gait (knee flexion associated with ankle dorsiflexion). Hamstring lengthening is performed to decrease stance knee flexion. However, this procedure carries the potential risk of weakening hip extension power as well as recurrence over time; therefore, surgeons have adopted a modified procedure wherein the semitendinosus and gracilis are transferred above the knee joint, along with lengthening of the semimembranosus and biceps femoris.

Purpose

The purpose of our study is to evaluate the differences between hamstring lengthening alone (HSL group) and hamstring lengthening plus transfer (HST group) in the treatment of flexed knee gait in ambulatory children with CP. We hypothesized that recurrence of increased knee flexion in the stance phase will be less in the HST group at long-term follow-up, and hip extensor power will be better preserved.

Methods

Fifty children with CP who underwent hamstring surgery for flexed knee gait were retrospectively reviewed. All subjects underwent a pre-operative gait study, a follow-up post-operative gait study, and a long-term gait study. The subjects were divided into two groups; HSL group (18 subjects) or HST group (32 subjects). The mean age at surgery was 9.9 ± 3.3 years. The mean follow-up time was 4.4 ± 0.9 (2.7–6.3) years.

Results

On physical examination, both groups showed improvement in straight leg raise, knee extension, popliteal angle, and maximum knee extension in stance at the first post-op study, and maintained this improvement at the long-term follow-up, with the exception of straight leg raise, which slightly worsened in both groups at the final follow-up. Both groups improved maximum knee extension in stance at the initial follow-up, and maintained this at the long-term follow-up. Only the HST group showed significant (p < 0.05) improvement in the peak hip extension power in stance at the first post-op study, and this increased further at the final follow-up. In the HSL group, there was an initial slight decrease in the hip extension power, which subsequently increased to pre-operative values at the long-term study. Only the HST group showed increase of the average anterior pelvic tilt at the long-term follow-up study, although this was small in magnitude. There were two subjects who developed knee recurvatum at the post-op study, and both were in the HST group.

Conclusions

There is no clear benefit in regards to recurrence when comparing HST to HSL in the long term. In both HSL and HST, there was reduction of stance phase knee flexion in the long term, with no clear advantage in either group. Longer follow-up is needed for additional recurrence information. There was greater improvement of hip extension power in the HST group, which may justify the additional operative time of the transfer.

Significance

This study helps pediatric orthopedic surgeons choose between two different techniques to treat flexed knee gait in patients with CP by showing the long-term outcome of both procedures.     

Isolated recession of the gastrocnemius muscle: the Baumann procedure

BACKGROUND: The Baumann procedure consists of intramuscular lengthening (recession) of the gastrocnemius muscle in the deep interval between the soleus and gastrocnemius muscles. The goal of the procedure is to increase ankle dorsiflexion when ankle movement is restricted by a contracted gastrocnemius muscle. Unlike the Vulpius procedure, the Baumann procedure truly isolates the lengthening site to the gastrocnemius muscle and does not lengthen the soleus muscle. The Baumann procedure has not previously been studied in cadaver specimens. METHODS: The gastrocnemius and soleus muscles of 15 normal cadaver specimens had four sequential releases: a single gastrocnemius recession, a second gastrocnemius recession, a single soleus recession, and an Achilles tenotomy. Ankle dorsiflexion was measured with a goniometer initially, after each muscle recession, and after the tenotomy. RESULTS: After the second gastrocnemius recession, the average increase in ankle dorsiflexion measured 14 degrees with the knee extended and 8 degrees with the knee flexed. CONCLUSIONS: The Baumann procedure treats equinus contracture of the gastrocnemius muscle by improving ankle joint dorsiflexion. The procedure is indicated when the results of the Silfverski?ld test are positive.     

Gait pattern in patients with spastic diplegic cerebral palsy who underwent staged operations

Fifteen patients with spastic diplegic cerebral palsy (CP) were monitored for a mean length of 9.5 years after they underwent staged operations and were evaluated by gait analysis, including joint motion in the sagittal plane and the ground reaction force (GRF) in three dimensions. Results showed an increased hip flexion (132%) at midstance, a reduction of peak knee flexion (PKF) during swing (45%) accompanied by an augmented time of PKF during swing (50%), and an increased dorsiflexion of the ankle during swing (293%) as well as its time during the gait cycle, in comparison with normal values. Moreover, significant decreases of the vertical GRF at the terminal stance and the forward and backward GRF were present. Additionally, it was found that a bilateral popliteal angle < 20 degrees is acceptable in spastic CP. Staged operations gave unpredictable results in the correction of contracture of the hamstrings, the Achilles tendon, and the iliopsoas. The authors are convinced that gait analysis is useful in evaluating these patients and enhances the results of operative treatment, and they have since changed their approach toward multilevel simultaneous corrections.     

Treatment for idiopathic toe-walking: results at skeletal maturity

Thirteen skeletally mature subjects who had been treated as children for idiopathic toe-walking underwent gait analysis and calf muscle strength testing at an average of 10.8 years from the last intervention. Six had had serial casting only; seven had had either a percutaneous tendo Achilles lengthening or a Baker's gastroc-soleus lengthening. Sagittal plane kinematics at the ankle was altered in 12 of the 13 subjects, but the changes were detectable visually in only 3 subjects. One subject had increased ankle plantarflexion at initial contact, but the other 12 subjects had a normal first rocker. Peak ankle dorsiflexion in stance averaged only 9 degrees, and 11 of the subjects had a peak ankle dorsiflexion in stance greater than 2 standard deviations below normative values. Ankle dorsiflexion was also restricted on passive measures, but there was no correlation between ankle dorsiflexion non-weight-bearing and in gait. Inversion of second rocker was seen in two subjects with peak ankle dorsiflexion in stance occurring before 25% of the gait cycle. Power generation by the calf during a single heel-rise test was variable between subjects but within normative values compared with controls. The authors conclude that most subjects showed persistent changes in ankle kinematics and kinetics despite treatment but that this was not detectable visually in most subjects.     

Botulinum A toxin for treatment of lower limb spasticity in cerebral palsyGait analysis in 49 patients

Background: Injection of botulinum type A toxin is a new treatment for spasticity. Patients and methods: We evaluated the effect of botulinum A toxin (BTX-A) in the lower limb muscles of patients having cerebral palsy. We tested 49 patients before and, on average, 4 (2-9) months after giving the toxin. The evaluation included 3-dimensional computerized gait analysis, changes in mobility level, using the Gillette Functional Assessment Questionnaire, and gastrocnemius muscle bulk, using ultrasonographic measurements. Results: The patients were divided into 3 groups, according to the site of BTX-A administration (hamstrings, gastrocnemius and multilevel). Those who were injected in the hamstrings showed a significant improvement in only the maximum knee extension angle during the gait cycle. Those with spastic equinus who were injected in the gastrocnemius muscle responded better than the other groups. The ankle angle on the initial contact, terminal stance and preswing, maximum dorsiflexion, ankle range of motion, per cent of single support and gait velocity improved significantly. Overall, the patients showed significant improvements in motor skill performance and functional health. Interpretation: Our findings indicate that botulinum type A toxin can be given as an adjuvant to conservative treatment of patients with cerebral palsy.     

Botulinum A toxin for treatment of lower limb spasticity in cerebral palsy: gait analysis in 49 patients

BACKGROUND: Injection of botulinum type A toxin is a new treatment for spasticity. PATIENTS AND METHODS: We evaluated the effect of botulinum A toxin (BTX-A) in the lower limb muscles of patients having cerebral palsy. We tested 49 patients before and, on average, 4 (2-9) months after giving the toxin. The evaluation included 3-dimensional computerized gait analysis, changes in mobility level, using the Gillette Functional Assessment Questionnaire, and gastrocnemius muscle bulk, using ultrasonographic measurements. RESULTS: The patients were divided into 3 groups, according to the site of BTX-A administration (hamstrings, gastrocnemius and multilevel). Those who were injected in the hamstrings showed a significant improvement in only the maximum knee extension angle during the gait cycle. Those with spastic equinus who were injected in the gastrocnemius muscle responded better than the other groups. The ankle angle on the initial contact, terminal stance and pre-swing, maximum dorsiflexion, ankle range of motion, per cent of single support and gait velocity improved significantly. Overall, the patients showed significant improvements in motor skill performance and functional health. INTERPRETATION: Our findings indicate that botulinum type A toxin can be given as an adjuvant to conservative treatment of patients with cerebral palsy.     

The effect on gait of lengthening of the medial hamstrings in cerebral palsy

The purpose of this study was to analyze the effect of lengthening of the medial hamstrings on the gait of patients who had spastic cerebral palsy. Thirty-one patients had preoperative and postoperative gait analyses. Standard parameters, such as velocity, cadence, and stride length, were evaluated, as were motion graphs of the hip, knee, and ankle. There was little difference between the preoperative and postoperative mean values for velocity, cadence, and stride length, which were expressed as percentages of normal for the patient's age. The contours of the postoperative motion graphs of the knees changed very little compared with those of the preoperative graphs; when a graph showed restricted motion preoperatively, it did so postoperatively. Although extension of the knee in stance phase improved postoperatively, the improvement was accompanied by decreased flexion of the knee during swing phase. When spasticity of both the hamstrings and the quadriceps was noted on the preoperative electromyogram, motion of the knee in the sagittal plane was markedly restricted.     

Outcome of patients after Achilles tendon lengthening for treatment of idiopathic toe walking

Fifteen children who were diagnosed with idiopathic toe walking that cannot be corrected by nonoperative treatment were assessed by clinical examination and computer-based gait analysis preoperatively and approximately 1 year after Achilles tendon lengthening. Passive dorsiflexion improved from a mean plantarflexion contracture of 8 degrees to dorsiflexion of 12 degrees after surgery. Ankle kinematics normalized, with mean ankle dorsiflexion in stance improving from -8 to 12 degrees and maximum swing phase dorsiflexion improving from -20 to 2 degrees. Peak ankle power generation increased from 2.05 to 2.37 W/kg but did not reach values of population norms. No patient demonstrated clinically relevant triceps surae weakness or a calcaneal gait pattern. Seven patients had a stance phase knee hyperextension preoperatively, and 6 of these corrected after surgery. Achilles tendon lengthening improves ankle kinematics without compromising triceps surae strength; however, plantarflexion power does not reach normal levels at 1 year after surgery.     

Isolated gastrocnemius tightness

BACKGROUND: Contracture of the gastrocnemius-soleus complex has well-documented deleterious effects on lower-limb function in spastic or neurologically impaired individuals. There is scarce literature, however, on the existence of isolated gastrocnemius contracture or its impact in otherwise normal patients. We hypothesized that an inability to dorsiflex the ankle due to equinus contracture leads to increased pain in the forefoot and/or midfoot and therefore a population with such pain will have less maximum ankle dorsiflexion than controls. We further postulated that the difference would be present whether the knee was extended or flexed. METHODS: This investigation was a prospective comparison of maximal ankle dorsiflexion, as a proxy for gastrocnemius tension, in response to a load applied to the undersurface of the foot in two healthy age, weight, and sex-matched groups. The patient group comprised thirty-four consecutive patients with a diagnosis of metatarsalgia or related midfoot and/or forefoot symptoms. The control group consisted of thirty-four individuals without foot or ankle symptoms. The participants were clinically examined for gastrocnemius and soleus contracture and were subsequently assessed for tightness with use of a specially designed electrogoniometer. Measurements were made both with the knee extended (the gastrocnemius under tension) and with the knee flexed (the gastrocnemius relaxed). RESULTS: With the knee fully extended, the average maximal ankle dorsiflexion was 4.5 degrees in the patient group and 13.1 degrees in the control group (p < 0.001). With the knee flexed 90 degrees, the average was 17.9 degrees in the patient group and 22.3 degrees in the control population (p = 0.09). When gastrocnemius contracture was defined as dorsiflexion of < or = 5 degrees during knee extension, it was identified in 65% of the patients compared with 24% of the control population. However, when gastrocnemius contracture was defined as dorsiflexion of < or = 10 degrees, it was present in 88% and 44%, respectively. When gastrocnemius-soleus contracture was defined as dorsiflexion of < or = 10 degrees with the knee in 90 degrees of flexion, it was identified in 29% of the patient group and 15% of the control group. CONCLUSIONS: On the average, patients with forefoot and/or midfoot symptoms had less maximum ankle dorsiflexion with the knee extended than did a control population without foot or ankle symptoms. When the knee was flexed 90 degrees to relax the gastrocnemius, this difference was no longer present. Clinical Relevance: These findings support the existence of isolated gastrocnemius contracture in the development of forefoot and/or midfoot pathology in otherwise healthy people. These data may have implications for preventative and therapeutic care of patients with chronic foot problems.     

Comparison of changes in posterior tibialis muscle length between subjects with posterior tibial tendon dysfunction and healthy controls during walking

STUDY DESIGN: Case control study. OBJECTIVE: To compare posterior tibialis (PT) length between subjects with stage II posterior tibial tendon dysfunction (PTTD) and healthy controls during the stance phase of gait. BACKGROUND: The abnormal kinematics demonstrated by subjects with stage II PTTD are presumed to be associated with a lengthened PT musculotendon, but this relationship has not been fully explored. METHODS: Seventeen subjects with stage II PTTD and 10 healthy controls volunteered for this study. Subject-specific foot kinematics were collected using 3-D motion analysis techniques for input into a general model of PT musculotendon length (PTLength). The kinematic inputs included hindfoot eversion/inversion (HF Ev/lnv), forefoot abduction/adduction (FF Ab/Add), forefoot plantar flexion/dorsiflexion (FF Pf/Df), and ankle plantar flexion/dorsiflexion (Ankle Pf/Df). To estimate the change in PTLength from neutral the following model was used: PTLength = 0.401(HF Ev/lnv) + 0,270(FF Ab/Add) + 0.137(FF Pf/Df) + 0.057(Ankle Pf/Df). Positive values indicated lengthening from the subtalar neutral (STN) position, while negative values indicated shortening relative to the STN position. A 2-way analysis of variance (ANOVA) model was used to compare PTLength between groups across the stance phases of walking (loading response, midstance, terminal stance, and preswing). Also, a 2-way ANOVA was used to assess the foot kinematics that contributed to alterations in PTLength. The Short Musculoskeletal Functional Assessment Index and Mobility subscale were used to compare function and mobility. RESULTS: PTLength was significantly greater (lengthened) relative to the STN position in the PTTD group compared to the control group across all phases of stance, with the greatest between-group difference in PTLength occurring during preswing. The greater PTLength in subjects with PTTD compared to controls was principally attributed to significantly greater HF Ev/lnv during loading response (P = .014) and midstance (P = .015). During terminal stance and preswing, each kinematic input to estimate PTLength contributed to lengthening (main effect, P = .03 and P = .01, respectively). Subjects with PTTD with abnormally greater PTLength reported significantly lower function (P = .04) and mobility (P = .03) compared to subjects with PTTD with normal PTLength during walking. CONCLUSIONS: The greater PTLength, as determined from foot kinematics, suggests that the PT musculotendon is lengthened in subjects with stage II PTTD, compared to healthy controls. The amount of lengthening is not dependent on the phase of gait; however, different foot kinematics contribute to PTLength across the stance phase. Targeting these foot kinematics may limit lengthening of the PT musculotendon. Subjects with excessive PT lengthening experience a decrease in function.     

Ankle dorsiflexion after isolated medial versus complete proximal gastrocnemius recession: A cadaveric study

PurposeGastrocnemius recession has been described in the treatment of gastrocnemius contracture. The aims of this study were: (1) to assess the change in ankle dorsiflexion after isolated medial gastrocnemius recession performed according to L.S. Barouk’s technique; (2) to compare ankle dorsiflexion after isolated medial head with complete proximal gastrocnemius recession.MethodsA cadaveric study was performed on 15 lower limb adult specimens. Isolated medial gastrocnemius head recession was initially performed, followed by an additional recession of the lateral gastrocnemius head. Ankle dorsiflexion torque was applied with 2 and 4 kg forces on second metatarsal head. Ankle dorsiflexion was measured with the knee both in extension and at 90° of flexion and values were recorded before surgery (T0), after medial head recession (T1) and after both heads recession (T2). Normality of data was assessed using the Shapiro–Wilk test, then measurements were compared in the three conditions with appropriate statistical tests.ResultsAfter isolated medial gastrocnemius recession (Δ = T1-T0), ankle dorsiflexion assessed with the knee in extension significantly increased by 5° ± 3 (range, −2 to 10) with a 2-kg torque (p = 0.02) and by 4.5° ± 3 (range, −4 to 10) with a 4-kg torque (p = 0.04). No significant difference was observed with the knee flexed at 90° (p > 0.05 for all measurements). After both gastrocnemius heads recession (Δ = T2-T1), although a further increase in dorsiflexion was noticed, statistical significance was not reached neither with the knee in extension nor at 90° of flexion (p > 0.05 for all measurements).ConclusionIn this study, isolated medial gastrocnemius head recession performed according to LS Barouk’s technique was effective in improving ankle dorsiflexion, whereas the additional release of the lateral head did not produce any significant change.Level of evidenceLevel V, cadaveric study.     

Reliability and validity of visual assessments of gait using a modified physician rating scale for crouch and foot contact

This study evaluates the visual assessment of gait using portions of the Physicians' Rating Scale (PRS). Thirty children with pathologic gait were evaluated "live" and using full- and slow-speed video. Interobserver reliability (weighted kappa) was 0.57 to 0.74 for foot contact, 0.69 to 0.71 for crouch, 0.30 to 0.40 for hip flexion, 0.57 to 0.65 for knee flexion, and 0.42 to 0.52 for dorsiflexion in stance. Intraobserver reliability (comparing the three conditions) was 0.50 to 0.78 for foot contact, 0.71 to 0.80 for crouch, 0.26 to 0.44 for hip flexion, 0.60 to 0.86 for knee flexion, and 0.39 to 0.61 for dorsiflexion. Observers were correct only 12% to 32% of the time when reporting less than 0 degrees of dorsiflexion and 0% to 29% of the time when reporting more than 20 degrees of hip flexion due to overestimation of hip flexion and underestimation of ankle dorsiflexion. These errors could lead some clinicians to presume the presence of contractures that do not actually exist. Visual assessment using the PRS does not appear to accurately measure what it is most commonly used to assess: ankle position in stance.     

A comparative study between isolated gastrocnemius tightness patients and controls by quantitative Gait analysis and baropodometry

BackgroundIsolated gastrocnemius tightness (IGT) has been suggested as an etiologic factor in mechanical disorders of the foot and ankle without a clear pathophysiological mechanism in the literature. We hypothesized that restricted ankle dorsiflexion inducing increased forefoot pressure in IGT patients could be this pathophysiological mechanism.MethodsCase/control experimental observational investigation. Forty lower limbs in 20 asymptomatic IGT patients were included and compared to controls. Quantitative gait analyses coupled with dynamic baropodometry were used for comparison between groups. The primary outcome was maximum ankle dorsiflexion during stance phase. Secondary outcomes were knee flexion and forefoot pressure.ResultsMaximum ankle dorsiflexion and maximum forefoot pressure were similar between groups. Increased knee flexion was found in the asymptomatic IGT group.ConclusionsIGT induced compensatory knee flexion during stance phase, which probably prevents increased pressure on the forefoot by allowing ankle dorsiflexion.Level of evidenceLevel IV, Case/control experimental observational investigation.     

Gait abnormalities following slipped capital femoral epiphysis

The authors evaluated 30 subjects with treated unilateral slipped capital femoral epiphysis and a range of severity from mild to severe to characterize gait and strength abnormalities using instrumented three-dimensional gait analysis and isokinetic muscle testing. For slip angles less than 30 degrees, kinematic, kinetic, and strength variables were not significantly different from age- and weight-matched controls. For moderate to severe slips, as slip angle increased, passive hip flexion, hip abduction, and internal rotation in the flexed and extended positions decreased significantly. Persistent pelvic obliquity, medial lateral trunk sway, and trunk obliquity in stance increased, as did extension, adduction, and external rotation during gait. Gait velocity and step length decreased with increased amount of time spent in double limb stance. Hip abductor moment, hip extension moment, knee flexion moment, and ankle dorsiflexion moment were all decreased on the involved side. Hip and knee strength also decreased with increasing slip severity. All of these changes were present on the affected and to a lesser degree the unaffected side. Body center of mass translation or pelvic obliquity in mid-stance greater than one standard deviation above normal correlated well with the impression of compensated or uncompensated Trendelenburg gait.     

The effect on ankle dorsiflexion of gastrocnemius recession

Gastrocnemius equinus contracture has been suggested as an etiologic factor in mechanical diseases of the foot and ankle and in ulcer formation in the foot. The purpose of this study is to assess the correction in ankle dorsiflexion that can be achieved with a gastrocnemius recession. An isolated gastrocnemius release (Strayer procedure) was performed on 26 legs, in 20 consecutive patients, for clinically significant gastrocnemius equinus contracture. Ankle dorsiflexion was assessed using a validated electrogoniometer. Ankle dorsiflexion was recorded with the knee straight and with the knee bent. Measurements were recorded preoperatively, and immediately postoperatively. Measurements at an average of 55.0 days postsurgery (range, 37 to 128 days) were performed on 20 legs (15 patients). RESULTS: Average preoperative ankle dorsiflexion with the knee straight was 5.1 degrees. Average preoperative ankle dorsiflexion with the knee bent was 22.8 degrees. Immediately following surgery the average ankle dorsiflexion with the knee straight was 23.2 degrees. The average correction was 18.1 degrees and this increase was significant (p < 0.0001.) In the 15 patients (20 legs) available for follow-up, the increase in ankle dorsiflexion with the knee straight was maintained (average: 24.9 degrees). Patients with gastrocnemius contracture who underwent an isolated gastrocnemius release increased their ankle dorsiflexion (knee straight) by an average of 18.1 degrees with postoperative ankle dorsiflexion (knee straight) being equivalent (23.2 and 22.8 degrees) to preoperative ankle dorsiflexion (knee bent). This correction appears to be maintained (23.2 vs. 24.9 degrees) at short-term follow-up.