Changes in sagittal ground reaction forces after intra-articular hyaluronate injections for knee osteoarthritis

OBJECTIVES: To examine the gait patterns and the sagittal ground reaction forces (GRFs) in persons with knee osteoarthritis (OA) after intra-articular injection of hyaluronate and to investigate the duration of its treatment effectiveness. DESIGN: Case-comparison study. SETTING: Gait laboratory in a tertiary care center. PARTICIPANTS: Fifteen subjects (30 knees) with symptomatic knee OA (stage I or II, according to the Ahlb?ck grading system), and 15 age-, mass-, and gender-matched non-OA control subjects (30 knees). INTERVENTION: After initial gait analysis, the group with knee OA received 5 weekly intra-articular injections of hyaluronate to bilateral knees. Gait analysis was performed again for the group with knee OA after the completion of hyaluronate injections. MAIN OUTCOME MEASURES: Forceplate sagittal GRFs and gait parameters of velocity, cadence, step length, and stride time. RESULTS: The distinctive 2-peak force vector GRF was lost in persons with knee OA. The first peak rise time was significantly delayed (P<.05). The group with knee OA also revealed slower walking velocity and cadence, as well as longer stride time, than the control group (P<.05). The distinctive 2-peak force vector GRF diagram could be recovered in patients with knee OA after the completion of hyaluronate injections. CONCLUSIONS: Gait patterns and GRFs improved significantly after intra-articular knee injection of hyaluronate in persons with Ahlb?ck stages I and II knee OA. The clinical treatment effect was immediate and may last for 6 months or more.     

The characteristics of multi-directional step distance and the association between stepping laterality and walking ability of patients with stroke

[Purpose] The purpose of this study was to determine the effect of stepping limb and step direction on step distance and the association of step distance and stepping laterality in step difference with walking ability and motor dysfunction. [Subjects and Methods] The subjects were thirty-nine patients with chronic hemiparesis as a result of stroke, who performed the MSL (Maximum Step Length) test along with tests of motor impairment, gait speed and Functional Ambulation Category. The MSL test is a clinical test of stepping distance in which participants step to the front, side, and back. The subjects were classified into three groups according to the stepping laterality in front step distance. [Results] Step distance did not differ across stepping limbs but did differ across step directions. Front step distance was significantly longer than side and back step distance. Participants with forward paretic step length shorter than forward non-paretic step length had significantly higher walking ability than participants with symmetric forward step length or forward paretic step length longer than forward non-paretic step length [Conclusion] Patients with stroke have characteristic step distances in each direction. Adequate weight shift toward the paretic limb when stepping with the non-paretic limb is associated with walking ability.Key words: Maximum step length, Stepping laterality, Stroke     

The effects of changes in the sagittal plane alignment of running-specific transtibial prostheses on ground reaction forces

[Purpose] To verify the effects of sagittal plane alignment changes in running-specific transtibial prostheses on ground reaction forces (GRFs). [Subjects and Methods] Eight transtibial amputees who used running-specific prostheses during sprinting participated. The sprint movements were recorded using a Vicon-MX system and GRF measuring devices. The experiment levels were set as regularly recommended alignment (REG; the normal alignment for the subjects) and dorsiflexion or plantar flexion from the REG. [Results] The subjects were classified into fast (100-m personal best < 12.50 s) and slow (100-m personal best ≥ 12.50 s) groups. In both groups, there were no significant differences in the center of gravity speed; further, the difference in the stance time was significant in the slow group but not in the fast group. Significant differences were observed in the step length for the fast group, whereas the stance time and step rate significantly differed in the slow group. The GRF impulse showed significant differences in the vertical and braking directions in both groups. [Conclusion] The GRFs are affected by sagittal plane alignment changes in running-specific prostheses. Moreover, our results suggest that the change in GRFs along with the altered sagittal plane alignment influenced the step length and step rate.Key words: Transtibial amputee, running-specific prosthesis, ground reaction force     

The effect of foot placement on sit to stand in healthy young subjects and patients with hemiplegia

OBJECTIVE: To determine the effect of altering the foot placement of the dominant limb in young healthy subjects and the uninvolved limb of subjects with hemiplegia on their ability to perform sit to stand (STS). DESIGN: Controlled biomechanical experiment. SETTING: Research laboratory of a university health science center. PARTICIPANTS: Nonrandom convenience sample of 10 healthy and 10 subjects with hemiplegia. Respective mean ages were 26 and 59 years. All patients with hemiplegia could ambulate and STS independently. The mean time since the stroke was 3.6 years. INTERVENTIONS: Subjects came from a sitting to a standing position under 3 different conditions: (1) normal condition, where both limbs were placed in 100 degrees of knee flexion; (2) limb extended condition, where the dominant or uninvolved limb was extended to 75 degrees of knee flexion; and (3) limb elevated condition, where the dominant or uninvolved limb was placed on a dense foam support equal to 25% of the subject's knee height. MAIN OUTCOME MEASURES: Vertical and anteroposterior ground reaction forces (GRFs) and bilateral tibialis anterior and quadriceps electromyogram (EMG) activity. RESULTS: In the young subjects, the normally placed nondominant limb compensated for the extended or elevated position of the dominant limb. Peak GRFs and EMG amplitudes were all significantly greater for the nondominant limb. In patients with hemiplegia, the EMG of the involved limb increased 39% in the limb-elevated and -extended conditions compared with the normal condition. Respective values for the uninvolved limb decreased. GRFs were significantly greater for the uninvolved limb except for the vertical force in the limb-extended position. CONCLUSIONS: Muscle activity and GRFs can be influenced by altering the initial foot placement of the dominant or uninvolved limb during STS. These initial data have positive implications for the rehabilitation of patients with hemiplegia who could be taught to overcome a reduced ability to use their impaired limb after stroke.     

Reliability of ground reaction force measurements during dynamic transitions from bipedal to single-limb stance in healthy adults.

The consistency of ground reaction force (GRF) variables underlying dynamic transitions from bipedal to single-limb stance during a single-leg flexion movement was examined in 18 healthy adult subjects aged 21 to 47 years (mean = 31.1, SD = 8.6). Force platforms were used to measure the GRFs during fast and natural speeds of movement. Separate intraclass correlation coefficients (ICCs) were calculated for three temporal variables (ie, onset of the propulsive and braking phases of the lateral horizontal GRF component and time to unload the flexing limb) and for two magnitude variables (ie, propulsive impulse [PROP] and braking impulse [BRAK]). The ICCs for both PROP and BRAK were > or = .73 for fast movements and > or = .88 at the natural speed. The ICCs for the temporal variables were > or = .66 at fast speeds and > or = .37 at the natural speed. We concluded that measurements of PROP and BRAK are reliable across a range of speeds during transitions in stance support and that these variables may be tightly regulated by the movement control system. Temporal variables, particularly at the natural speed, exhibited lower reliability estimates, suggesting that measurements of these events have greater variability. Reliability of measurements of GRF variables provides useful information for the clinician regarding underlying control processes governing dynamic transitions in stance support.     

Longitudinal changes in transtibial amputee gait characteristics when negotiating a change in surface height during continuous gait

Background

Negotiating a raised surface during continuous gait is an important activity of daily living and is a potentially hazardous task with regards to trips, falls and fall-related injury. However, it is not known how recent transtibial amputees adapt to performing stepping gait tasks in the 6-month period following discharge from rehabilitation.

Methods

Recent transtibial amputees performed continuous gait trials, stepping onto and from a raised surface walkway representing the height of a street kerb, whilst kinematic and kinetic data were recorded at one, three and six months post-discharge from rehabilitation.

Findings

Walking speed increased when stepping down (p = 0.04) and was invariant across the study period when stepping up. At one month post-discharge, participants displayed an affected lead limb preference (90.8%) when stepping down and an intact lead limb preference (70.0%) when stepping up, although these lead limb preferences diminished over time. Participants spent more time in stance on the intact limb compared to the affected limb in both stepping down (trail limb) (p = 0.01) and stepping up (lead and trail limbs) (p = 0.05). Participants displayed significantly greater joint mobility and power bursts in the intact trail limb when stepping down and in the intact lead limb when stepping up.

Interpretation

Transtibial amputees prefer to exploit intact limb function to a greater extent, although over time, the means by which this occurs changes which affects the initial lead limb preferences. The results from the current study enable future evidence-based therapeutic and prosthetic interventions to be designed that improve transtibial amputee stepping gait.     

The gait initiation process in unilateral lower-limb amputees when stepping up and stepping down to a new level

BACKGROUND: Unilateral lower-limb amputees lead with their intact limb when stepping up and with their prosthesis when stepping down; the gait initiation process for the different stepping directions has not previously been investigated. METHODS: Ten unilateral amputees (5 transfemoral and 5 transtibial) and 8 able-bodied controls performed single steps up and single steps down to a new level (73 and 219 mm). Duration, a-p and m-l centre of mass and centre of pressure peak displacements and centre of mass peak velocity of the anticipatory postural adjustment and step execution phase were evaluated for each stepping direction by analysing data collected using a Vicon 3D motion analysis system. FINDINGS: There were significant differences (in the phase duration, peak a-p and m-l centre of pressure displacement and peak a-p and m-l centre of mass velocity at heel-off and at foot-contact) between both amputee sub-groups and controls (P<0.05), but not between amputee sub-groups. These group differences were mainly a result of amputees adopting a different gait initiation strategy for each stepping direction. INTERPRETATION: Findings indicate the gait initiation process utilised by lower-limb amputees was dependent on the direction of stepping and more particularly by which limb the amputee led with; this suggests that the balance and postural control of gait initiation is not governed by a fixed motor program, and thus that becoming an amputee will require time and training to develop alternative neuromuscular control and coordination strategies. These findings should be considered when developing training/rehabilitation programs.     

Foot contact pattern analysis in hemiplegic stroke patients: an implication for neurologic status determination

OBJECTIVE: To investigate the feasibility of using a foot contact pattern to predict neurologic recovery and the effect of ambulation training in hemiplegic stroke patients. DESIGN: Case-comparison study. SETTING: Gait laboratory in a tertiary care center. PARTICIPANTS: Sixty-five functionally ambulant hemiplegic stroke patients, and 30 healthy subjects serving as the control group. INTERVENTIONS: Gait analyses were performed by using the conventional gait analysis system (6 cameras) and the portable Computer DynoGraphy (CDG) system.Main outcome measures Walking velocity, step length, and cadence were measured from the conventional gait analysis system. Cyclogram, gaitline, and ground reaction force (GRF) patterns were recorded with the CDG system. RESULTS: Velocity, cadence, and step length increased in higher Brunnstrom stages (P<.01). Negative correlation was noted between the Brunnstrom stages and the foot contact patterns (P<.01). Lower cyclogram, GRF, and gaitline patterns were expected in subjects with higher Brunnstrom stages. There were high prediction probabilities between cyclogram, gaitline, and GRF patterns. CONCLUSIONS: Foot contact pattern can be a simple and reliable indicator of hemiplegic gait in stroke patients. It is closely related to patient's neurologic status and is correlated with parameters obtained from conventional gait analysis systems. Pathologic presentations are noted in both the affected and unaffected limbs, suggesting that rehabilitation programs should be implemented on both sides.     

Longitudinal gait analysis of a person with a transfemoral amputation using three different prosthetic knee/foot pairs

Using gait analysis, we documented kinetic and temporospatial changes over a 7-year period in a single healthy individual with a transfemoral amputation walking with three different knees and matched foot components. The knee/foot pairs in chronological order were Four Bar Endolite knee/Endolite Dynamic Response foot; Ossur Total Knee 2000/Pathfinder I foot; and C-Leg knee/IC40 C-walk foot. The design of the suspension and socket were unchanged across the three prostheses. We found an increase in the braking component of A-P ground reaction force on the intact limb while using the C-Leg compared to the other two prosthetic fabrications. There was progressive change across the three component combinations, which included increased step length, increased walking velocity, and decreased double limb support time. The subject ranked the C-Leg system as the most stable. The final gait pattern with the C-Leg was faster, less cautious, and more stable than with the other prosthetic components.     

The effects of light touch cue on gait initiation in patients with Parkinson's disease

IntroductionOne of the common impairments in patients with Parkinson's disease (PD) is disturbance of gait initiation. A light touch cue improves postural stability in patients with PD. Little is known about the effects of a light touch cue on gait initiation. This study investigated the effects of a light touch on gait initiation in patients with PD.MethodsThis study was a cross-sectional study design. Sixteen patients with PD (Hoehn & Yahr stage 2–3) participated in the study and were evaluated two gait conditions (no touch (NT) and light touch (LT) conditions). Gait initiation was divided into 5 events including event A, B, C, D, and E. Outcome measures included maximum center of pressure (COP) displacement and velocity in anteroposterior (AP) and mediolateral (ML) directions, and the first step time.ResultsParticipants with LT had greater COP displacement compared with the NT condition in all events of gait initiation except COP-AP displacement in event D. Additionally, the COP velocity in LT condition was faster than the NT condition in COP-ML velocity in event A, COP-AP velocity in event B, COP-AP velocity and COP-ML velocity in event C. Moreover, participants with LT presented significantly shorter the first step time than the NT condition.ConclusionsThese findings demonstrated that a light touch cue improved gait initiation in patients with PD by increased weight shifting to initial stance limb, increased postural stability of stance limb, increased velocity of weight transfer toward stance limb, and a shortened first step time.     

Longitudinal gait analysis of a person with a transfemoral amputation using three different prosthetic knee/foot pairs

Using gait analysis, we documented kinetic and temporospatial changes over a 7–year period in a single healthy individual with a transfemoral amputation walking with three different knees and matched foot components. The knee/foot pairs in chronological order were Four Bar Endolite knee/Endolite Dynamic Response foot; Ossur Total Knee 2000/Pathfinder I foot; and C-Leg knee/IC40 C-walk foot. The design of the suspension and socket were unchanged across the three prostheses. We found an increase in the braking component of A-P ground reaction force on the intact limb while using the C-Leg compared to the other two prosthetic fabrications. There was progressive change across the three component combinations, which included increased step length, increased walking velocity, and decreased double limb support time. The subject ranked the C-Leg system as the most stable. The final gait pattern with the C-Leg was faster, less cautious, and more stable than with the other prosthetic components.     

Effect of Aging on Seated Stepping Variability

[Purpose] Accuracy in coordinating limb movements decreases with aging. The effect of aging on the variability of cyclic movements is not well known. The aim of this study was to examine the effect of aging on seated stepping variability. [Subjects and Methods] Twenty-six healthy young adults and 15 healthy elderly adults were instructed to walk at their preferred speed. Foot contact was monitored using reflective markers. Seated stepping was performed on force plates. The participants synchronized their stepping with 6 different metronome beats: 90–140 beats per minute (bpm). The time-series coefficient of variation (CV) was calculated. [Results] The cadence of young adults was 121 steps/min and that of the elderly adults was 125 steps/min in the elderly adults. The seated stepping CV decreased gradually from 90 to 120 bpm, but sharply increased at 130 and 140 bpm. Compared to young adults, the elderly adults had significantly higher CVs of seated stepping; however, the intergroup difference in the CV of seated stepping at 120 bpm was negligible. [Conclusions] Our results suggest that the stepping accuracy of the elderly is decreased; however, the rhythmic seated stepping accuracy does not decrease at the same rate as gait.Key words: Aging, Stepping, Variability     

Effects of increasing non-paretic step length on paretic leg movement during hemiparetic gait: a pilot study

[Purpose] Gait training that increases non-paretic step length in stroke patients increases the propulsive force of the paretic leg. However, it limits knee flexion during the swing phase of gait, and this may cause gait disturbances such as worsening of gait pattern and increased risk of falling. Therefore, this study aimed to investigate the effects of increasing non-paretic step length on the joint movement and muscle activity of a paretic lower limb during hemiparetic gait. [Participants and Methods] A total of 15 hemiparetic patients with chronic stroke were enrolled in this study. Spatiotemporal parameters, along with kinematic and electromyography data of their paretic lower limbs, were measured during a 10-m distance overground walking. Two walking conditions were assessed: normal (comfortable gait) and non-paretic-long (gait with increased non-paretic step length) conditions. [Results] Under the non-paretic-long condition, the trailing limb angle was larger than under the normal condition. However, no significant difference was observed in the knee flexion angle during the swing phase. [Conclusion] Increasing non-paretic step length during gait is unlikely to limit knee flexion during the swing phase and can safely improve the propulsive force of a paretic leg.     

Effect of the Modulation of Optic Flow Speed on Gait Parameters in Children with Hemiplegic Cerebral Palsy

[Purpose] We investigated the effects of modulation of the optic flow speed on gait parameters in children with hemiplegic cerebral palsy. [Methods] We examined 10 children with hemiplegic cerebral palsy. The children underwent gait analysis under 3 different conditions of optic flow speed: slow, normal, and fast optic flow speed. The children walked across the walkway of a GAITRite system, while watching a virtual reality screen, and walking velocity, cadence, stride length, step length, single support time, and double support time were recorded. [Results] Compared with the other applied flow speed conditions, the fast optic flow speed (2 times the normal speed) significantly increased walking velocity, cadence, normalized step length, base of support, and single support cycle of both the paretic and non-paretic lower limbs. Moreover, compared with the other applied flow speed conditions, the slow optic flow speed (0.25 times the normal speed) yielded a significantly decreased walking velocity, cadence, normalized step length, base of support, and single support cycle for both the paretic and non-paretic lower limbs. [Conclusion] The gait parameters of children with hemiplegic cerebral palsy are altered by modulation of the optic flow speed. Thus, we believe that gait training involving modulation of the optic flow speed is feasible and suitable for resolving abnormal gait patterns in children with hemiplegic cerebral palsy.Key words: Optic flow, Gait parameter, Hemiplegic cerebral palsy     

Gait characteristics of individuals with multiple sclerosis before and after a 6-month aerobic training program

Individuals who have multiple sclerosis (MS) typically experience problems with physical activities such as walking, resulting from the combined effects of skeletal muscle weakness, sensory disturbances, spasticity, gait ataxia, and reduction in aerobic capacity. The aim of this study was to determine whether a 6-mo exercise program designed for aerobic conditioning might also affect gait abnormalities in individuals with MS. Subjects included 18 individuals with MS who presented a range of disability. Passive range of motion (PROM) in the lower limbs was measured and gait analyzed before and after exercise conditioning. Three-dimensional kinematics, ground reaction forces (GRF), and electromyographic information were acquired as subjects walked at self-selected velocities. Hip PROM increased following conditioning. Mean walking velocity, cadence, and posterior shear GRF (push-off force) decreased. During walking, maximum ankle dorsiflexion decreased and ankle plantarflexion increased. Total knee flexion/extension range during the walking cycle decreased slightly as did maximum hip extension. Results suggest this 6-mo training program had minimal effect on gait abnormalities.     

Activity of lower limb muscles during treadmill running at different velocities

[Purpose] The present study aimed to determine changes in muscle activity while moving on a treadmill at various speeds. [Subjects] The activities of the left vastus lateralis, vastus medialis, hip adductors, lateral head of gastrocnemius, medial head gastrocnemius, soleus, and tibialis anterior of 10 healthy male university students were analyzed. [Methods] University students walked, jogged, and ran for 10 minutes each in random order, and then myogenic potentials were measured 10 minutes later for 30 seconds. The flexion angle of the lower limb upon initial contact, mid stance, and toe off were measured. [Results] The average walking, jogging, and running speeds were 3.6 ± 0.4, 6.7 ± 0.6, and 10.4 ± 1.3 km/h, respectively. The average electromyographic activities of the vastus medial, tibialis anterior, medial head of gastrocnemius, and lateral head of gastrocnemius significantly differed. All muscles were more active during jogging and running than walking. Only the soleus was more active during running than walking, and the activities of the hip adductors and vastus lateralis did not significantly differ. [Conclusion] Velocity is faster and the angles of the lower limbs and ground reaction force (GRF) are larger during running than walking. The vastus medialis and soleus worked more easily according to the angle of the knee joint, whereas the tibialis anterior worked more easily at faster velocities and the medial and lateral heads of the gastrocnemius worked more easily with an increased GRF.Key words: Walking, Running, Skeletal muscle     

Effect of prosthetic gel liner thickness on gait biomechanics and pressure distribution within the transtibial socket

Prosthetic gel liners are often prescribed for persons with lower-limb amputations to make the prosthetic socket more comfortable. However, their effects on residual limb pressures and gait characteristics have not been thoroughly explored. This study investigated the effects of gel liner thickness on peak socket pressures and gait patterns of persons with unilateral transtibial amputations. Pressure and quantitative gait data were acquired while subjects walked on liners of two different uniform thicknesses. Fibular head peak pressures were reduced (p = 0.04) with the thicker liner by an average of 26 +/- 21%, while the vertical ground reaction force (GRF) loading peak increased 3 +/- 3% (p = 0.02). Most subjects perceived increased comfort within the prosthetic socket with the thicker liner, which may be associated with the reduced fibular head peak pressures. Additionally, while the thicker liner presumably increased comfort by providing a more compliant limb-socket interface, the higher compliance may have reduced force and vibration feedback to the residual limb and contributed to the larger vertical GRF loading peaks. We conclude that determining optimal gel liner thickness for a particular individual will require further investigations to better identify and understand the compromises that occur between user perception, residual-limb pressure distribution, and gait biomechanics.     

The relationship between bilateral knee muscle strength and gait performance after stroke: the predictive value for gait performance

[Purpose] The purpose of this study was to assess the relationships between bilateral knee extension strengths and gait performance in subjects with poststroke hemiparesis and to predict gait performance by the paretic and nonparetic knee extension strength. [Subjects and Methods] This was a correlational study in which 238 consecutive inpatients with poststroke hemiparesis were enrolled. Knee extensor muscle strengths in paretic and nonparetic lower limbs were measured with a handheld dynamometer, and the presence or absence of impaired gait was also determined. [Results] The mean strength in the paretic lower limb was 0.90 Nm/kg, and that in the nonparetic lower limb was 1.24 Nm/kg. Discriminant analysis classified the difference between the possibility and impossibility of gait by knee extensor muscle strength (standardized discriminant coefficient: paretic, 1.32; nonparetic, 0.55). Thus, paretic and nonparetic knee extension strengths were integrated in the strength index. A threshold level of 2.0 provided the best balance between positive and negative predictive values for the strength index. [Conclusion] The results indicated that both paretic and nonparetic knee extension strengths were related to gait performance. The strength index deduced from bilateral knee extension strengths may serve as a clinically meaningful index for rehabilitation assessment and training.Key words: Stroke, Handheld dynamometer, Gait     

Effect of an exercise program on functional performance of institutionalized elderly

This study determined the effectiveness of a 6-month program of regular exercises for the improvement of functional performance of the elderly living in a nursing home. The 40 subjects aged 60 to 99 who took part in this trial were assigned either to a comparative group or an exercise group. The following variables were measured: functional performance with the use of an obstacle course, a lower-limb function test, and a 6-minute walk test (gait velocity); isometric strength of the knee extensors; proprioception of the lower limbs; mental status through the Mini-Mental State Examination (MMSE); and depression symptoms with the use of the Geriatric Depression Scale (GDS). In the exercise group, 19 subjects completed the program and attended an average of 32 (68%) sessions. At the end of the trial, the exercise subjects showed significant performance improvement in quantitative and qualitative obstacle course scores, lower-limb function test, gait velocity test, knee extensors strength, and the GDS, while the nonexercise subjects showed significant decrease in qualitative obstacle course score, lower-limb function, gait velocity, MMSE, and the GDS.     

Effect of Horseback Riding Simulation Machine Training on Trunk Balance and Gait of Chronic Stroke Patients

[Purpose] The purpose of this study was to assess the effect of horseback riding simulation machine training on trunk balance and gait of patients with chronic stroke. [Subjects and Methods] The subjects were 20 patients hospitalized for treatment after being diagnosed with stroke. Horseback riding simulation training was provided for 30 minutes, 5 times a week, for 6 weeks. Trunk balance was assessed using the Trunk Impairment Scale (TIS) and a balance measuring device (Biorescue, RM ingenierie, France), and gait ability was measured using the Functional Gait Assessment (FGA) and a gait analyzer (GAITRite, CIR system Inc., USA). [Results] There were significant changes in movement area, distance and velocity of body sway as measured by the TIS and the balance measuring device, and in gait velocity, cadence, stride length and double limb support as measured by the FGA and gait analyzer. [Conclusion] Horseback riding simulation training improved the trunk balance and gait of chronic stroke patients. This present study provides preliminary objective data for future research, and useful clinical information for physical therapists using horseback riding simulation machines as a treatment modality for patients with chronic stroke.Key words: Horseback riding simulation machine training, Trunk balance, Gait