Jaimie A. Roper

Acute Aquatic Treadmill Exercise Improves Gait and Pain in People With Knee Osteoarthritis

OBJECTIVE To examine the acute effects of aquatic and land treadmill exercise on gait kinematics as well as the level of disease-specific and movement-related pain for individuals with osteoarthritis. DESIGN Quasi-experimental crossover design. SETTING Biomechanics laboratory. PARTICIPANTS Participants (N=14; age, 43-64y) diagnosed with osteoarthritis at the knee (n=12), osteoarthritis at the knee and ankle (n=1), or osteoarthritis at the knee and hip (n=1). INTERVENTIONS Participants performed 3 exercise sessions separated by at least 24 hours in 1 week for each mode of exercise (aquatic treadmill and land treadmill). MAIN OUTCOME MEASURES Gait kinematics and pain were measured before and after each intervention. RESULTS The angular velocity gain score during stance for left knee extension was improved by 38% after aquatic treadmill exercise (P=.004). Similarly, during swing, the gain scores for angular velocity were also greater for left knee internal rotation and extension by 65% and 20%, respectively (P=.004, P=.008, respectively). During stance, the joint angle gain score for left hip flexion was 7.23% greater after land exercise (P=.007). During swing, the angular velocity gain score for right hip extension was significantly greater for aquatic exercise by 28% (P=.01). Only the joint angle gain score for left ankle abduction during stance was significantly higher after land exercise (4.72%, P=.003). No other joint angle gain scores for either stance or swing were significantly different for either condition (P=.06-.96). Perceived pain was 100% greater after land than aquatic treadmill exercise (P=.02). Step rate and step length were not different between conditions (P=.31-.92). CONCLUSIONS An acute training period on an aquatic treadmill positively influenced joint angular velocity and arthritis-related joint pain. Acute aquatic treadmill exercise may be useful as a conservative treatment to improve angular speed of the lower-extremity joints and pain related to osteoarthritis.

Does acute whole-body vibration training improve the physical performance of people with knee osteoarthritis?

Abstract Salmon, JR, Roper, JA, and Tillman, MD. Does acute whole-body vibration training improve the physical performance of people with knee osteoarthritis? J Strength Cond Res 26(11): 2983–2989, 2012—The purpose of this study was to determine the effects of a single session of whole-body vibration training (WBVT) on the physical performance of individuals with knee osteoarthritis (OA) in 3 tests designed to simulate activities of daily living (ADLs). Fifteen individuals with symptomatic knee OA completed the Timed-Up-and-Go Test, step test, 20-m walk test, and visual analog scale (VAS) recordings of knee pain intensity. A main effect was detected for time to complete the step test (F[2,28] = 6.243, p = 0.006, ). Post hoc analyses revealed that the time to complete the step test at 5 minutes after WBVT improved significantly (p = 0.042) from that of the pretest. A moderate correlation (r = 0.465, p = 0.001) was found between the VAS scores and the time to complete the step test across all trials. A main effect was found for time to complete the walk test (F[2,28] = 4.370, p = 0.022, ). Post hoc analyses did not indicate significant improvements from pretest seen at 5 minutes after WBVT (p = 0.110) and 1 hour after WBVT (p = 0.224). The WBVT was well tolerated in nearly all the participants, and we observed that an acute bout of WBVT was effective in improving the ability of individuals with knee OA to perform a step test and 20-m walk test. Our findings suggest that WBVT may be an effective nonpharmacologic modality to treat some knee OA symptoms and improve ADLs.

Split-Belt Treadmill Walking Alters Lower Extremity Frontal Plane Mechanics

Interventions that manipulate gait speed may also affect the control of frontal plane mechanics. Expanding the current knowledge of frontal plane adaptations during split-belt treadmill walking could advance our understanding of the influence of asymmetries in gait speed on frontal plane mechanics and provide insight into the breadth of adaptations required by split-belt walking (SBW). Thirteen young, healthy participants, free from lower extremity injury walked on a split-belt treadmill with belts moving simultaneously at different speeds. We examined frontal plane mechanics of the ankle, knee, and hip joints during SBW, as well as medio-lateral ground reaction forces (ML-GRF). We did not observe alterations in the frontal mechanics produced during early or late adaptation of SBW when compared to conditions where the belts moved together. We did observe that ML-GRF and hip moment impulse of the fast limb increased over time with adaptation to SBW. These results suggest this modality may provide a unique therapy for individuals with gait pathologies, impairments, or compensation(s).

Comparison of Metabolic Cost, Performance, and Efficiency of Propulsion Using an Ergonomic Hand Drive Mechanism and a Conventional Manual Wheelchair

OBJECTIVE To compare the metabolic cost (oxygen uptake per unit time [V˙o2 consumption], heart rate, and number of pushes), performance (velocity and distance traveled), and efficiency (oxygen uptake per distance traveled [Vo2 efficiency]) of propulsion using a novel ergonomic hand drive mechanism (EHDM) and a conventional manual wheelchair (CMW). DESIGN Repeated-measures crossover design. SETTING Semicircular track. PARTICIPANTS Adult full-time manual wheelchair users with spinal cord injuries (N=12; mean age ± SD, 38.8±12.4y; mean body mass ± SD, 73.7±13.3kg; mean height ± SD, 173.6±11.1cm) who were medically and functionally stable and at least 6 months postinjury. INTERVENTION Participants propelled themselves for 3.5 minutes at a self-selected pace in a CMW and in the same chair fitted with the EHDM. MAIN OUTCOME MEASURES Velocity, distance traveled, number of pushes, V˙o2 consumption, Vo2 efficiency, and heart rate were compared by wheelchair condition for the last 30 seconds of each trial using paired t tests (α=.01). RESULTS The CMW condition resulted in more distance traveled (33.6±10.8m vs 22.4±7.8m; P=.001), greater velocity (1.12±0.4m/s vs .75±.30m/s; P=.001), and better Vo2 efficiency (.10±.03mL·kg(-1)·m(-1) vs .15±.03mL·kg(-1)·m(-1); P<.001) than the EHDM condition, respectively. No significant differences were found between the 2 conditions for number of pushes (27.5±5.7 vs 25.7±5.4; P=.366), V˙o2 consumption (6.43±1.9mL·kg(-1)·min(-1) vs 6.19±1.7mL·kg(-1)·min(-1); P=.573), or heart rate (100.5±14.5 beats per minute vs 97.4±20.2 beats per minute; P=.42). CONCLUSIONS The results demonstrate that metabolic costs did not differ significantly; however, performance and efficiency were sacrificed with the EHDM. Modifications to the EHDM (eg, addition of gearing) could rectify the performance and efficiency decrements while maintaining similar metabolic costs. Although not an ideal technology, the EHDM can be considered as an alternative mode of mobility by wheelchair users and rehabilitation specialists.

Oxygen consumption, oxygen cost, heart rate, and perceived effort during split-belt treadmill walking in young healthy adults

During split-belt treadmill walking the speed of the treadmill under one limb is faster than the belt under the contralateral limb. This unique intervention has shown evidence of acutely improving gait impairments in individuals with neurologic impairment such as stroke and Parkinson’s disease. However, oxygen use, heart rate and perceived effort associated with split-belt treadmill walking are unknown and may limit the utility of this locomotor intervention. To better understand the intensity of this new intervention, this study was undertaken to examine the oxygen consumption, oxygen cost, heart rate, and rating of perceived exertion associated with split-belt treadmill walking in young healthy adults. Fifteen participants completed three sessions of treadmill walking: slow speed with belts tied, fast speed with belts tied, and split-belt walking with one leg walking at the fast speed and one leg walking at the slow speed. Oxygen consumption, heart rate, and rating of perceived exertion were collected during each walking condition and oxygen cost was calculated. Results revealed that oxygen consumption, heart rate, and perceived effort associated with split-belt walking were higher than slow treadmill walking, but only oxygen consumption was significantly lower during both split-belt walking than fast treadmill walking. Oxygen cost associated with slow treadmill walking was significantly higher than fast treadmill walking. These findings have implications for using split-belt treadmill walking as a rehabilitation tool as the cost associated with split-belt treadmill walking may not be higher or potentially more detrimental than that associated with previously used treadmill training rehabilitation strategies.

Adaptation Strategies of Individuals With Anterior Cruciate Ligament Reconstruction

Background: Despite the strong implications for rehabilitation design, the capability of individuals with anterior cruciate ligament reconstruction (ACLR) to adapt and store novel gait patterns have not been well studied. Purpose: To investigate how reconstructive surgery may affect the ability to adapt and store novel gait patterns in persons with ACLR while walking on a split-belt treadmill. Study Design: Controlled laboratory study. Methods: Gait adaptation was compared between 20 participants with ACLR and 20 healthy controls during split-belt treadmill walking. Gait adaptation was assessed in slow- and fast-adapting parameters by (1) the magnitude of symmetry during late adaptation and (2) the amount of the asymmetry during de-adaptation. Results: Healthy individuals adapted a new walking pattern and stored the new walking pattern equally in both the dominant and nondominant limbs. Conversely, individuals with ACLR displayed impairments in both slow-adapting and fast-adapting derived gait adaptation and significant differences in behavior between the reconstructed and uninjured limb. Conclusion: While surgical reconstruction and physical therapy are aimed at improving mechanical stability to the knee, the study data suggest that fundamental features of motor control remain altered. After ACLR, participants display an altered ability to learn and store functional gait patterns.

Wheelchair ergonomic hand drive mechanism use improves wrist mechanics associated with carpal tunnel syndrome

Among conventional manual wheelchair (CMW) users, 49% to 63% experience carpal tunnel syndrome (CTS) that is likely induced by large forces transmitted through the wrist and extreme wrist orientations. The ergonomic hand drive mechanism (EHDM) tested in this study has been shown to utilize a more neutral wrist orientation. This study evaluates the use of an EHDM in terms of wrist orientations that may predispose individuals to CTS. Eleven adult full-time CMW users with spinal cord injury participated. Motion data were captured as participants propelled across a flat surface, completing five trials in a CMW and five trials in the same CMW fitted with the EHDM. Average angular wrist orientations were compared between the two propulsion styles. Use of the EHDM resulted in reduced wrist extension and ulnar deviation. The shift to more neutral wrist orientations observed with EHDM use may reduce median nerve compression.

Cognitive Performance and Locomotor Adaptation in Persons With Anterior Cruciate Ligament Reconstruction

Background. Persons with anterior cruciate ligament reconstruction (ACLR) show deficits in gait and neuromuscular control following rehabilitation. This altered behavior extends to locomotor adaptation and learning, however the contributing factors to this observed behavior have yet to be investigated. Objective. The purpose of this study was to assess differences in locomotor adaptation and learning between ACLR and controls, and identify underlying contributors to motor adaptation in these individuals. Methods. Twenty ACLR individuals and 20 healthy controls (CON) agreed to participate in this study. Participants performed four cognitive and dexterity tasks (local version of Trail Making Test, reaction time test, electronic pursuit rotor test, and the Purdue pegboard). Three-dimensional kinematics were also collected while participants walked on a split-belt treadmill. Results. ACLR individuals completed the local versions of Trails A and Trails B significantly faster than CON. During split-belt walking, ACLR individuals demonstrated smaller step length asymmetry during EARLY and LATE adaptation, smaller double support asymmetry during MID adaptation, and larger stance time asymmetry during DE-ADAPT compared with CON. Conclusions. ACLR individuals performed better during tasks that required visual attention and task switching and were less perturbed during split-belt walking compared to controls. Persons with ACLR may use different strategies than controls, cognitive or otherwise, to adapt locomotor patterns.

Perception of symmetry and asymmetry in individuals with anterior cruciate ligament reconstruction

BACKGROUND Changes in the quantity, quality and integration of sensory information are thought to persist long after anterior cruciate ligament reconstruction and completion of physical therapy. Our purpose was to investigate the ability of individuals with anterior cruciate ligament reconstruction to perceive imposed asymmetry and symmetry while walking. METHODS Twenty participants with anterior cruciate ligament reconstruction and 20 controls walked on a split-belt treadmill while we assessed the ability to detect symmetry and asymmetry at fast and slow speeds. Detection scores and spatiotemporal data during asymmetric and symmetric tasks in which the belts were coupled or decoupled over time were recorded. FINDINGS The ability to detect symmetry and asymmetry was not altered in individuals with anterior cruciate ligament reconstruction compared to healthy young adults. The belt-speed ratio at detection also correlated to asymmetry for step length, stride length, double support time, and stance time. However, the anterior cruciate ligament reconstruction group appeared to utilize unique information to determine detection. When asked to detect symmetry at a fast speed, no asymmetry scores significantly correlated with belt-speed ratio in the anterior cruciate ligament reconstruction group. Conversely, asymmetry in stride length, step length, and stance time all significantly correlated with belt-speed ratio at detection in the control group. INTERPRETATION Specific sensory cues arising from the speed of the leg may also augment perception of symmetry. This strategy may be necessary in order to successfully execute the motor task, and could develop due to altered sensory information from the reconstructed knee at faster walking speeds.