Physiological measurements of walking and running in people with transtibial amputations with 3 different prostheses.

STUDY DESIGN: A 3-factor (foot type, speed, and mode of ambulation) repeated-measures experimental design was used. OBJECTIVES: To compare the differences in energy expenditure, gait efficiency, and relative exercise intensity in persons with transtibial amputations with various prostheses. BACKGROUND: There is a need for improved prosthetic designs to accommodate physically active persons with lower-extremity amputations. METHODS AND MEASURES: We used progressive speeds of treadmill walking (53.64, 67.05, 80.46, 93.87, and 107.28 m/min) and running (120.69, 134.1, and 147.51 m/min) with 3 different types of prostheses: the Solid Ankle Cushion Heel (SACH) foot, the Flex-Foot (FF), and the Re-Flex Vertical Shock Pylon (VSP) prosthesis. Five physically active men with unilateral transtibial amputations served as subjects (aged 31.6 +/- 4.28 years). RESULTS: The following statistically significant differences (improvements) between the Re-Flex VSP versus the FF and the SACH foot were found. Energy cost: walking (5%), running (11%); gait efficiency: walking (6%), running (9%); relative exercise intensity: walking (4%), running (5%). However, we found no significant differences between the FF and the SACH. CONCLUSIONS: The Re-Flex VSP appears to have a positive effect on energy cost, efficiency, and relative exercise intensity compared with the other prosthetic foot types during walking and running.     

Lack of relationship between gait parameters and physical function in peripheral arterial disease

OBJECTIVE: Physical function is limited in patients with peripheral arterial disease who are symptomatic with intermittent claudication (PAD-IC). When patients with PAD-IC experience claudication, previous reports have described gait abnormalities, including alterations in step length and cadence. This study tested the hypothesis that patients with PAD-IC would have a decrease in usual and maximal walking speed and that this alteration in gait parameters would contribute to their decreased physical function scores, even in the absence of claudication. The aims were to evaluate usual and maximal walking speed and gait parameters (step length, cadence and toe out angle) in subjects with PAD-IC and control subjects with similar baseline activity levels. METHOD: A cross-sectional study of 25 subjects with PAD-IC compared with 26 age-matched controls was conducted in a research laboratory in an academic medical center. Study subjects were similar in age, gender, and physical activity status. Subjects with PAD-IC had an ankle-brachial index <0.90 in at least one leg and reported symptoms of intermittent claudication that limited walking ability. Subjects in either group were excluded if they used assistive devices to walk or were limited in walking ability by orthopedic, neurologic, cardiac, or pulmonary symptoms. Gait parameters were assessed at the onset of walking (before the development of claudication pain in the PAD-IC group) at self-selected and maximal walking speeds during which step and stride characteristics were collected. Subjects completed a physical activity recall, a Short Form questionnaire (SF-36), and a 6-minute walk that was limited by claudication in the PAD-IC group. RESULTS: During gait testing, no patient with PAD-IC developed claudication. There were no significant differences between the PAD-IC and control groups in usual or maximal walking speed or other gait variables (step length, cadence, stride width, toe out angle). In contrast, the SF-36 physical function score was reduced 15.2 percentage points (P < .02) and the summary physical component score was reduced 6.7 percentage points in the PAD-IC group compared with controls (P = .002). In addition, the 6-minute walk distance was significantly less in the PAD-IC group than in the control group by 308.8 feet (P < .001). A series of bivariate analyses demonstrated that PAD-IC was the best predictor of reduced physical function, whereas no gait parameter was associated with reduced physical function. CONCLUSION: Patients with PAD-IC have significantly reduced 6-minute walk distance and reduced physical function by questionnaire scores that was not explained by any effects of PAD-IC on walking speed and selected gait parameters assessed before the onset of claudication pain.     

Supervised walking exercise therapy improves gait biomechanics in patients with peripheral artery disease

ObjectiveIn patients with peripheral artery disease (PAD), supervised exercise therapy is a first line of treatment because it increases maximum walking distances comparable with surgical revascularization therapy. Little is known regarding gait biomechanics after supervised exercise therapy. This study characterized the effects of supervised exercise therapy on gait biomechanics and walking distances in claudicating patients with PAD.MethodsForty-seven claudicating patients with PAD underwent gait analysis before and immediately after 6 months of supervised exercise therapy. Exercise sessions consisted of a 5-minute warmup of mild walking and stretching of upper and lower leg muscles, 50 minutes of intermittent treadmill walking, and 5 minutes of cooldown (similar to warmup) three times per week. Measurements included self-perceived ambulatory limitations measured by questionnaire, the ankle-brachial index (ABI), walking distance measures, maximal plantar flexor strength measured by isometric dynamometry, and overground gait biomechanics trials performed before and after the onset of claudication pain. Paired t-tests were used to test for differences in quality of life, walking distances, ABI, and maximal strength. A two-factor repeated measures analysis of variance determined differences for intervention and condition for gait biomechanics dependent variables.ResultsAfter supervised exercise therapy, quality of life, walking distances, and maximal plantar flexor strength improved, although the ABI did not significantly change. Several gait biomechanics parameters improved after the intervention, including torque and power generation at the ankle and hip. Similar to previous studies, the onset of claudication pain led to a worsening gait or a gait that was less like healthy individuals with a pain-free gait.ConclusionsSix months of supervised exercise therapy produced increases in walking distances and quality of life that are consistent with concurrent improvements in muscle strength and gait biomechanics. These improvements occurred even though the ABI did not improve. Future work should examine the benefits of supervised exercise therapy used in combination with other available treatments for PAD.     

Relationship between temporal-spatial gait parameters, gait kinematics, walking performance, exercise capacity, and physical activity level in peripheral arterial disease

OBJECTIVE: Impaired physical function is a feature of patients with peripheral arterial disease (PAD) who present with symptoms of intermittent claudication (PAD-IC). Previous research found that temporal-spatial gait parameters do not discriminate between PAD-IC patients and control subjects during normal and maximal walking even though PAD-IC patients have decreased physical function characteristic of the disease. This study examined the hypothesis that patients with PAD-IC would demonstrate decreased temporal-spatial gait parameters, gait kinematics, walking performance, physiologic responses to exercise, and physical activity level compared with control subjects. The aim was to examine the temporal-spatial gait parameters and gait kinematics of individuals with PAD-IC and to determine the relationship between these variables and walking performance, exercise capacity, and physical activity level in these individuals. METHOD: A cross-sectional study of 28 PAD-IC subjects (IC) and 25 controls (CON) matched for age and mass was conducted in a medical faculty human performance laboratory. IC subjects had a history of PAD, ankle-brachial pressure index (ABI)<0.9 in at least one leg, and a positive Edinburgh Claudication Questionnaire response. Gait characteristics were determined by two-dimensional motion analysis. A graded treadmill test was used to assess walking performance and peak physiologic responses to exercise. Physical activity levels were measured by analysis of 7-day pedometer recording motion. Differences between groups were examined by one-way analysis of covariance. RESULTS: Compared with CON, IC temporal-spatial gait parameters were significantly lower (P<.05), except for single support ipsilateral limb time. IC subjects spent a greater percentage of time in gait support phases, took longer to complete a stride, and had reduced stride length and walking speeds during the gait cycle. IC joint angular kinematics showed significantly reduced displacement of ankle plantar flexion (P=.017), knee range of motion (P=.021), and hip extension (P=.016) compared with the CON subjects during the gait cycle. All joint minimum and maximum angular velocities and accelerations, walking physiologic responses, and physical activity levels were significantly lower for IC compared with the CON subjects. CONCLUSION: IC subjects walk with a shuffling gait pattern indicated by reduced joint angular displacement, velocities, and accelerations that results in reduced walking performance and physiologic responses and physical activity compared with controls matched for age, mass, and physical activity.     

Average patient walking activity approaches 2 million cycles per year: pedometers under-record walking activity

A two-dimensional accelerometer worn on the ankle (step activity monitor [SAM]; Prosthetic Research Study, Seattle, WA) has been proved to be highly accurate for assessing walking activity. The walking activity of 33 patients with well-functioning total hip arthroplasties was measured continuously during daily life, simultaneously with a pedometer and a SAM. The SAM recorded an average of 1.9 million cycles/y. The pedometer under-recorded an average of 34% cycles per day compared with the SAM (P=.0007), but the 2 measures were highly correlated (r=0.66; P=.001). No difference was seen in the number of gait cycles per day between men and women. The previously reported difference in average walking activity between men and women is due to greater under-recording of the pedometer in women, especially those with a body mass index > or =27. The pedometer is more reliable in quantifying the walking activity of men, less obese women, and patients with >1 million gait cycles/y.     

The function of the toes in walking, jogging and running.

The foot has been studied in walking, running and jogging using high speed cinema photography in the laboratory for gait analysis in the Shriner's Hospital for Crippled Children, San Francisco. During running, as well as in walking, the extrinsic toe flexors restrain progression of the tibia. The extrinsic extensors accelerate the tibia over the fixed foot. The intrinsic toe muscles function from mid-stance to lift-off when the subject runs on his toes. In sprinting, the intrinsics are active throughout the weight-bearing phase.     

When Does A Gait Transition Occur During Human Locomotion?

When a treadmill accelerates continuously, the walk-run transition has generally been assumed to occur at the instant when a flight phase is first observed, while the run-walk transition has been assumed to occur at the instant of the first double support period. There is no theoretical or empirical evidence to suggest that gait transitions occur at the instant of these events, nor even whether transitions are abrupt events. The purpose of this study was to determine whether the gait transitions during human locomotion occur abruptly, and if so, to determine the instant during a stride at which a transition occurs. The time history of the vertical velocity of the hip (v_hip) and the angular velocity of the ankle (ω_ankle) were compared between constant speed strides (walking or running) and strides at and near the walk-run and run-walk transitions to determine if and when the transition strides resemble the stride of the corresponding constant speed strides. For both the walk-run and run-walk transitions, the stride prior to the transition resembled the original gait pattern, while the stride following the transition resembled the new gait pattern. The transition stride, however, did not resemble either a walking or a running stride during either of the transition directions. It was concluded that gait transitions are initiated at about midstance of the transition stride, but the transition is not completed until after an adjustment period of between one step and one stride. Thus, gait transitions are not abrupt events during human locomotion.

Key points

• Gait transitions are not abrupt events.
• Initiation of a gait transitions occur at about midstance of the transition stride.
• Gait transitions are completed approximately at the next heelstrike of the ipsilateral foot.
• Time period between initiation and completion of transition does not resemble either a walk or a run.

Key words: Gait changes, walking, running, treadmill locomotion     

Gait retraining for runners: in search of the ideal

For physical therapists, modifying technique is not a novel concept; however, our motives are typically focused on symptom and injury reduction rather than purely performance. These specific modifications are based on minimizing tissue load, while still enabling successful completion of the task. Applying this same rationale to running, an activity in which up to 80% of participants are injured annually, would seem to be a good thing. Yet the idea of using gait retraining in patients without neurological injury/pathology is rather uncommon. However, a few researchers have investigated specific walking retraining strategies to reduce knee joint loading, with the goal of applying these techniques to individuals with knee osteoarthritis. This has led some to use the same concept on runners with patellofemoral pain, with a corresponding improvement in gait and symptoms.     

Electromyography of idiopathic toe walking

Eighteen idiopathic toe walkers were evaluated by gait electromyography to define muscle timing abnormalities. This group was compared with a matched group of normal children walking on their toes and to a group of patients with cerebral palsy and equinus deformities. Although timing in all three groups differed from normal timing, the two patient groups showed some statistically significant differences in phasic timing from the control group. However, no significant differences existed between toe walking and spastic children. Historical data (family history, male predominance, and learning disabilities) suggest that idiopathic toe walking is a true entity, although the gait electromyograms were not diagnostic.     

Kinematic and EMG patterns during slow, free, and fast walking

Kinematics and electromyographic (EMG) activity were recorded in seven normal women during walking at slow, free, and fast speeds. Speed-related differences were found in the stride dimensions, temporal components, and most of the simultaneous displacement patterns of body segments measured. For most of the muscles tested, the amplitude of normalized EMG activity decreased as walking speed decreased. The findings emphasize the importance of accounting for the effect of speed itself on measurements of gait.     

Gait analysis after total hip replacement with hip resurfacing implant or Mallory-head Exeter prosthesis: a randomised controlled trial

A key to the analysis of function after total hip replacement (THR) is the ability to identify gait adaptations specific to design features and surgical procedures. In a randomised controlled design, we evaluated the mechanics of gait after THR with a hip resurfacing system or conventional prosthesis. We also investigated whether gait adaptations returned to normal postoperatively. Similar improvements in mechanics of gait were found, except for peak abductor moments, which improved more in the conventional group. Gait speed increased significantly, but with no differences between groups. The increase in walking speed was reflected as significant improvement within groups in most kinematic and kinetic variables. Significant differences between the operated and non-operated hip were seen in all patients, but with no difference between groups. Mean curves of joint angle profiles and moments in all anatomical planes during a gait cycle revealed that gait impairment persisted with no differences between the conventional prosthesis and the resurfacing system.     

Effective gait patterns for offloading the medial compartment of the knee

Gait modification offers a noninvasive option for offloading the medial compartment of the knee in patients with knee osteoarthritis. While gait modifications have been proposed based on their ability to reduce the external knee adduction moment, no gait pattern has been proven to reduce medial compartment contact force directly. This study used in vivo contact force data collected from a single subject with a force‐measuring knee replacement to evaluate the effectiveness of two gait patterns at achieving this goal. The first was a “medial thrust” gait pattern that involved medializing the knee during stance phase, while the second was a “walking pole” gait pattern that involved using bilateral walking poles commonly used for hiking. Compared to the subject's normal gait pattern, medial thrust gait produced a 16% reduction and walking pole gait a 27% reduction in medial contact force over stance phase, both of which were statistically significant based on a two‐tailed Mann–Whitney U‐test. While medial thrust gait produced little change in lateral and total contact force over the stance phase, walking pole gait produced significant 11% and 21% reductions, respectively. Medial thrust gait may allow patients with knee osteoarthritis to reduce medial contact force using a normal‐looking walking motion requiring no external equipment, while walking pole gait may allow patients with knee osteoarthritis or a knee replacement to reduce medial, lateral, and total contact force in situations where the use of walking poles is possible. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 1016–1021, 2009     

The gait of patients with one resurfacing and one replacement hip: a single blinded controlled study

Purposes

Post arthroplasty gait analysis has up till now been performed on subjects walking slowly on flat ground rather than challenging them at faster speeds or walking uphill. We therefore asked: (1) Is there a measurable difference in the performance of hip resurfacing arthroplasty (HRA) and total hip arthroplasty (THA) limbs at patients’ self-determined fastest walking speeds and steepest inclines? and (2) Is there a relationship between the observed differences between the gait of HRA and THA implanted limbs and patient walking speeds and inclines.

Methods

In an ethically approved study we recruited patients with bilateral hip arthroplasties: one HRA and one THA. Nine subjects were assessed using an instrumented treadmill at a range of speeds and inclines by a blinded observer. The ground reaction forces of subjects were recorded and an age, sex and BMI matched control group was used for comparison.

Results

Increasing walking speed correlated strongly with between leg differences in weight acceptance (r?=?0.9, p?=?0.000) and push-off force (r?=?0.79, p?=?0.002). HRA implanted limbs accepted significantly more weight at top walking speeds (1208 N?±?320 versus 1279 N?±?370, p?=?0.026) and pushed off with greater force when walking uphill (818 N?±?163 versus 855?±?166, p?=?0.012). HRA limbs more closely approximated to the gait of the normal control group.

Conclusions

Arthroplasty implants do have an impact on the gait characteristics of patients. Differences in gait are more likely to be evident when assessment is made at fast speeds and walking uphill. This study suggests that HRA may enable a more normal gait.     

Muscle-tendon surgery in diplegic cerebral palsy: functional and mechanical changes.

A prospective assessment of muscle-tendon (M-T) surgery was conducted on 30 patients with spastic diplegia. Muscle-tendon surgery consisted of recessions or releases to improve gait function by correcting restricted joint motion and joint malalignment. Functional-outcome measures included the Gross Motor Function Measure (GMFM) and temporal gait factors. Kinematic gait data were evaluated to determine the mechanical effects. The mean age at surgery was 8.7 years (4-20 years), and 3.5 muscle tendon units per extremity were recessed or released at surgery. The primary kinematic change for the hip and the knee was a shift in the sagittal joint position with minimal effects on overall excursion. Changes in ankle-joint dynamics after gastrocsoleus recessions included a reduction in plantarflexion and a shift in the timing of maximal dorsiflexion to later in stance. Improvements in walking velocity and stride length were evident by 6 month after surgery. Functional changes from M-T surgery included a 25% increase in velocity and an 18% increase in stride length over preoperative values seen at 9 months after surgery. Improvements in these parameters were maintained at 2 years after surgery. The GMFM total score showed minimal change after surgery with improvements occurring primarily in the standing dimension and the walking, running, and jumping dimensions.     

Effects of fast functional electrical stimulation gait training on mechanical recovery in poststroke gait

Stroke leads to gait impairments that can negatively influence quality of life. Functional electrical stimulation (FES) applied during fast walking (FastFES) is an effective gait rehabilitation strategy that can lead to improvements in gait performance, walking speed and endurance, balance, activity, and participation poststroke. The effect of FastFES gait training on mechanical energy utilization is not well understood. The objective of this study was to test the effects of 12 weeks of FastFES gait training on mechanical recovery indices of poststroke gait. Kinematic data were collected from 11 stroke survivors before and after 12 weeks of FastFES training. Mechanical recovery was calculated from the positive changes in vertical, anterior-posterior, and medial-lateral components of center of mass energy. The average mechanical recovery increased from 34.5% before training to 40.0% after training. The increase was statistically significant (P = 0.014). The average self-selected walking speed increased from 0.4 m/s to 0.7 m/s after the 12-week FastFES training. The results indicate that the subjects were better able to generate and utilize the external mechanical energy of walking after FastFES gait training. FastFES gait training has the capacity to increase the gait speed, improve the mechanical recovery, and reduce the mechanical energy expenditure of stroke survivors when they walk.     

The Complex Relationship Between In Vivo ACL Elongation and Knee Kinematics During Walking and Running

In vivo anterior cruciate ligament (ACL) bundle (anteromedial bundle [AMB] and posterolateral bundle [PLB]) relative elongation during walking and running remain unknown. In this study, we aimed to investigate in vivo ACL relative elongation over the full gait cycle during walking and running. Ten healthy volunteers walked and ran at a self‐selected pace on an instrumented treadmill while biplane radiographs of the knee were acquired at 100 Hz (walking) and 150 Hz (running). Tibiofemoral kinematics were determined using a validated model‐based tracking process. The boundaries of ACL insertions were identified using high‐resolution magnetic resonance imaging (MRI). The AMB and PLB centroid‐to‐centroid distances were calculated from the tracked bone motions, and these bundle lengths were normalized to their respective lengths on MRI to calculate relative elongation. Maximum AMB relative elongation during running (6.7 ± 2.1%) was significantly greater than walking (5.0 ± 1.7%, p = 0.043), whereas the maximum PLB relative elongation during running (1.1 ± 2.1%) was significantly smaller than walking (3.4 ± 2.3%, p = 0.014). During running, the maximum AMB relative elongation was significantly greater than the maximum PLB relative elongation (p < 0.001). ACL relative elongations were correlated with tibiofemoral six degree‐of‐freedom kinematics. The AMB and PLB demonstrate similar elongation patterns but different amounts of relative elongation during walking and running. The complex relationship observed between ACL relative elongation and knee kinematics indicates that ACL relative elongation is impacted by tibiofemoral kinematic parameters in addition to flexion/extension. These findings suggest that ACL strain is region‐specific during walking and running. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1920–1928, 2019     

The gait of patients with full weightbearing capacity after hip prosthesis implantation on the treadmill with partial body weight support, during assisted walking and without crutches]

PROBLEM: Treadmill training with partial body weight support is a new promising technique in the rehabilitation in hip arthroplasty patients. With little data on the gait pattern and extent of pelvitrochanteric muscle activation, this study analysed the gait of hip arthroplasty patients walking on the treadmill and also during floor walking with and without crutches. METHOD: Gait analysis in 19 hip arthroplasty patients capable of full weight bearing included the assessment of kinematics, kinetics and kinesiologic electromyogram of relevant trunk and lower limb muscles during treadmill walking with 15% of body weight support, and during floor walking with and without crutches at comparable walking velocities. RESULTS: Both on the treadmill and with crutches, patients walked less frequent, with a longer stride and more symmetric as compared to the unaided gait. Both techniques, however, resulted in a reduced activation of most of the pelvitrochanteric muscles, particularly when using crutches. The comparison of both supporting methods revealed a higher activity of the M. gluteus medius of the affected side on the treadmill. The amount of body weight reduction was comparable ranging from 10 to 15%. CONCLUSIONS: Treadmill training with constant body weight support enables hip arthroplasty patient to entrain a dynamic and symmetric gait pattern with a better activation of the hip abductor of the affected side as compared to walking with crutches. Nevertheless, the level of activation was less than when walking without crutches which, however, resulted in a limping gait pattern.     

In-vivo strain measurements to evaluate the strengthening potential of exercises on the tibial bone

Mechanical loading during physical activity produces strains within bones. It is thought that these forces provide the stimulus for the adaptation of bone. Tibial strains and rates of strain were measured in vivo in six subjects during running, stationary bicycling, leg presses and stepping and were compared with those of walking, an activity which has been found to have only a minimal effect on bone mass. Running had a statistically significant higher principal tension, compression and shear strain and strain rates than walking. Stationary bicycling had significantly lower tension and shear strains than walking. If bone strains and/or strain rates higher than walking are needed for tibial bone strengthening, then running is an effective strengthening exercise for tibial bone.     

Walking speed in children and young adults with neuromuscular disease: comparison between two assessment methods

Self-selected walking speed is being increasingly used as a primary outcome measure in the management of neuromuscular disease. It would be useful if the speed recorded in the gait laboratory represented the child's walking speed in the community. This study investigated the difference in self-selected walking speeds between a 10-meter walk, as measured during instrumented gait analysis, and a 10-minute walk. The authors found that self-selected walking speed during the 10-minute walk was slower than the self-selected walking speed recorded during the 10-meter walk. The former may be more representative of walking speed in the community setting. Walking speed measured during walks of 10 minutes or more should become an integral part of gait laboratory evaluation.