Efficacy of Sensory Transcutaneous Electrical Nerve Stimulation on Perceived Pain and Gait Patterns in Individuals With Experimental Knee Pain

Comparison of discrete and continuous analysis approaches for evaluating gait biomechanics in individuals with anterior cruciate ligament reconstruction

BACKGROUND

Aberrant gait biomechanics contribute to post-traumatic knee osteoarthritis development following anterior cruciate ligament reconstruction (ACLR). Walking gait biomechanics are typically evaluated post-ACLR by identifying discrete, peak values in the load acceptance phase of gait (i.e. first 50 %). As these approaches evaluate a single time instant during the gait cycle, functional data analysis (FDA) techniques that evaluate the entire stance phase waveform are becoming more common in the literature. However, it is unclear if these analysis approaches identify the same biomechanical phenomena.

RESEARCH QUESTION

The purpose of this study was to determine whether four gait biomechanics analysis approaches identify the same aberrant gait characteristics in individuals with ACLR.

METHODS

Twenty-four individuals with ACLR and 24 healthy controls completed gait analyses on an instrumented treadmill. Four analysis approaches were employed to compare the vertical ground reaction force and sagittal knee angles and moments during the first 50 % of the stance phase between groups and between limbs in the ACLR cohort: 1) comparison of peak values from individual trials (Peak), 2) comparison of peak values from time-normalized ensemble waveforms (Ensemble Peak), 3) FDA via functional ANCOVA (FANCOVA), and 4) FDA evaluating overlap of the 95 % confidence intervals for each waveform (FDA-CI).

RESULTS

The Peak, Ensemble Peak, and FANCOVA approaches identified highly similar group and limb differences in the biomechanics outcomes with respect to both magnitude and temporal location. However, the FANCOVA approach indicated that these differences were distributed across large portions of the load acceptance phase and that differences existed outside the first 50 % of stance. The FDA-CI approach was generally not effective for identifying aberrant gait biomechanics.

SIGNIFICANCE

Peak and FANCOVA approaches to gait analysis provide similar findings. Future research is necessary to determine if the additional information afforded by FANCOVA provides insight regarding the mechanical pathogenesis of post-traumatic knee osteoarthritis.

A Review of the Relationships Between Knee Pain and Movement Neuromechanics

CONTEXT

Knee injury and disease are common, debilitating, and expensive. Pain is a chief symptom of knee injury and disease and likely contributes to arthrogenic muscle inhibition. Joint pain alters isolated motor function, muscular strength, and movement biomechanics. Because knee pain influences biomechanics, it likely also influences long-term knee joint health.

OBJECTIVE

The purpose of this article is 2-fold: (1) review effects of knee pain on lower-extremity muscular activation and corresponding biomechanics and (2) consider potential implications of neuromechanical alterations associated with knee pain for long-term knee joint health. Experimental knee pain is emphasized because it has been used to mimic clinical knee pain and clarify independent effects of knee pain. Three common sources of clinical knee pain are also discussed: patellofemoral pain, anterior cruciate ligament injury and reconstruction, and knee osteoarthritis.

DATA SOURCES

The PubMed, Web of Science, and SPORTDiscus databases were searched for articles relating to the purpose of this article.

CONCLUSION

Researchers have consistently reported that knee pain alters neuromuscular activation, often in the form of inhibition that likely occurs via voluntary and involuntary neural pathways. The effects of knee pain on quadriceps activation have been studied extensively. Knee pain decreases voluntary and involuntary quadriceps activation and strength and alters the biomechanics of various movement tasks. If allowed to persist, these neuromechanical alterations might change the response of articular cartilage to joint loads during movement and detrimentally affect long-term knee joint health. Physical rehabilitation professionals should consider neuromechanical effects of knee pain when treating knee injury and disease. Resolution of joint pain can likely help to restore normal movement neuromechanics and potentially improve long-term knee joint health and should be a top priority.

Application of functional data analysis to explore movements: walking, running and jumping - A systematic review

Background Signals are continuously captured during the recording of motion data. Statistical analysis, however, usually uses only a few aspects of the recorded data. Functional data analysis offers the possibility to analyze the entire signal over time. Research question The review is based on the question of how functional data analysis is used in the study of lower limb movements. Methods The literature search was based on the databases EMBASE, PUBMED and OVID MEDLINE. All articles on the application of functional data analysis to motion-associated variables trajectories, ground reaction force,electromyography were included. The references were assessed independently by two reviewers. Results In total 1448 articles were found in the search. Finally, 13 articles were included in the review. All were of moderate methodological quality. The publication year of the studies ranges from 2009 to 2019. Healthy volunteers and persons with cruciate ligament injuries, knee osteoarthritis, gluteal tendinopathy, idiopathic torsional deformities, slipped capital femoral epiphysis and chronic ankle instability were examined in the studies. Movements were analyzed on basis of kinematics (3D motion analysis), ground reaction forces and electromyography. Functional Data Analysis was used in terms of landmark registration, functional principal component analysis, functional t-test and functional ANOVA. Significance Functional data analysis provides the possibility to gain detailed and in-depth insights into the analysis of motion patterns. As a result of the increase in references over the past year, the FDA is becoming more important in the analysis of continuous signals and the explorative analysis of movement data.

Simultaneous ice and transcutaneous electrical nerve stimulation decrease anterior knee pain during running but do not affect running kinematics or associated muscle inhibition

BACKGROUND

Runners often experience anterior knee pain and this pain is associated with altered running neuromechanics. The purpose of this study was to examine potential therapeutic benefits (reduced pain and restored running neuromechanics) of simultaneously applied ice and transcutaneous electrical nerve stimulation on experimentally-induced anterior knee pain.

METHODS

Nineteen healthy subjects completed a sham and treatment data collection session. For both sessions, hypertonic saline was infused into the infrapatellar fat pad for approximately 80 min to induce experimental anterior knee pain. Perceived pain levels were measured every two minutes and running neuromechanics were recorded at four time points: pre-pain, pain before treatment, pain immediately post-treatment, and pain 20 min post-treatment.

FINDINGS

The saline infusion significantly increased perceived knee pain from 0 to 2.8 cm. The ice/transcutaneous electrical nerve stimulation treatment significantly reduced perceived knee pain by 35%, six minutes after the treatment initiation. Perceived knee pain remained reduced until eight minutes after the treatment termination. The knee pain significantly decreased peak gluteus medius, vastus lateralis, and vastus medialis activation during running, each by an average of 17% plus/minus 6%; however, none of these decreases were resolved via the therapeutic treatment. Neither the knee pain nor the therapeutic treatment significantly affected peak gluteus maximus activation or peak hip adduction angle.

INTERPRETATION

The experimental pain model effectively produced anterior knee pain and decreased muscle activation during running. The simultaneous ice/transcutaneous electrical nerve stimulation treatment effectively decreased anterior knee pain, but did not restore running neuromechanics that were altered due to the pain.

Characterization of Multiple Movement Strategies in Participants With Chronic Ankle Instability

CONTEXT

Chronic ankle instability (CAI) is characterized by multiple sensorimotor deficits, affecting strength, postural control, motion, and movement. Identifying specific deficits is the key to developing appropriate interventions for this patient population; however, multiple movement strategies within this population may limit the ability to identify specific movement deficits.

OBJECTIVE

To identify specific movement strategies in a large sample of participants with CAI and to characterize each strategy relative to a sample of uninjured control participants.

DESIGN

Descriptive laboratory study.

SETTING

Biomechanics laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 200 individuals with CAI (104 men, 96 women; age = 22.3 ± 2.2 years, height = 174.2 ± 9.5 cm, mass = 72.0 ± 14.0 kg) were selected according to the inclusion criteria established by the International Ankle Consortium and were fit into clusters based on movement strategy. A total of 100 healthy individuals serving as controls (54 men, 46 women; age = 22.2 ± 3.0 years, height = 173.2 ± 9.2 cm, mass = 70.7 ± 13.4 kg) were compared with each cluster.

MAIN OUTCOME MEASURE(S)

Lower extremity joint biomechanics and ground reaction forces were collected during a maximal vertical jump landing, followed immediately by a side cut. Data were reduced to functional output or curves, kinematic data from the frontal and sagittal planes were reduced to a single representative curve for each plane, and representative curves were clustered using a Bayesian clustering technique. Estimated functions for each dependent variable were compared with estimated functions from the control group to describe each cluster.

RESULTS

Six distinct clusters were identified from the frontal-plane and sagittal-plane data. Differences in joint angles, joint moments, and ground reaction forces between clusters and the control group were also identified.

CONCLUSIONS

The participants with CAI demonstrated 6 distinct movement strategies, indicating that CAI could be characterized by multiple distinct movement alterations. Clinicians should carefully evaluate patients with CAI for sensorimotor deficits and quality of movement to determine the appropriate interventions for treatment.

Altered Movement Biomechanics in Chronic Ankle Instability, Coper, and Control Groups: Energy Absorption and Distribution Implications

CONTEXT

Patients with chronic ankle instability (CAI) exhibit deficits in neuromuscular control, resulting in altered movement strategies. However, no researchers have examined neuromuscular adaptations to dynamic movement strategies during multiplanar landing and cutting among patients with CAI, individuals who are ankle-sprain copers, and control participants.

OBJECTIVE

To investigate lower extremity joint power, stiffness, and ground reaction force (GRF) during a jump-landing and cutting task among CAI, coper, and control groups.

DESIGN

Cross-sectional study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 22 patients with CAI (age = 22.7 ± 2.0 years, height = 174.6 ± 10.4 cm, mass = 73.4 ± 12.1 kg), 22 ankle-sprain copers (age = 22.1 ± 2.1 years, height = 173.8 ± 8.2 cm, mass = 72.6 ± 12.3 kg), and 22 healthy control participants (age = 22.5 ± 3.3 years, height = 172.4 ± 13.3 cm, mass = 72.6 ± 18.7 kg).

INTERVENTION(S)

Participants performed 5 successful trials of a jump-landing and cutting task.

MAIN OUTCOME MEASURE(S)

Using motion-capture cameras and a force plate, we collected lower extremity ankle-, knee-, and hip-joint power and stiffness and GRFs during the jump-landing and cutting task. Functional analyses of variance were used to evaluate between-groups differences in these dependent variables throughout the contact phase of the task.

RESULTS

Compared with the coper and control groups, the CAI group displayed (1) up to 7% of body weight more posterior and 52% of body weight more vertical GRF during initial landing followed by decreased GRF during the remaining stance and 22% of body weight less medial GRF across most of stance; (2) 8.8 W/kg less eccentric and 3.2 W/kg less concentric ankle power, 6.4 W/kg more eccentric knee and 4.8 W/kg more eccentric hip power during initial landing, and 5.0 W/kg less eccentric knee and 3.9 W/kg less eccentric hip power; and (3) less ankle- and knee-joint stiffness during the landing phase. Concentric power patterns were similar to eccentric power patterns.

CONCLUSIONS

The CAI group demonstrated altered neuromechanics, redistributing energy absorption from the distal (ankle) to the proximal (knee and hip) joints, which coincided with decreased ankle and knee stiffness during landing. Our data suggested that although the coper and control groups showed similar landing and cutting strategies, the CAI group used altered strategies to modulate impact forces during the task.

Altered Walking Neuromechanics in Patients With Chronic Ankle Instability

CONTEXT

The literature on gait kinematics and muscle activation in chronic ankle instability (CAI) is limited. A comprehensive evaluation of all relevant gait measures is needed to examine alterations in gait neuromechanics that may contribute to recurrent sprain.

OBJECTIVE

To compare walking neuromechanics, including kinematics, muscle activity, and kinetics (ie, ground reaction force [GRF], moment, and power), between participants with and those without CAI by applying a novel statistical analysis to data from a large sample.

DESIGN

Controlled laboratory study.

SETTING

Biomechanics laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 100 participants with CAI (49 men, 51 women; age = 22.2 ± 2.3 years, height = 174.0 ± 9.7 cm, mass = 70.8 ± 14.4 kg) and 100 individuals without CAI serving as controls (55 men, 45 women; age = 22.5 ± 3.3 years, height = 173.1 ± 13.3 cm, mass = 72.6 ± 18.7 kg).

INTERVENTION(S)

Participants performed 5 trials of walking (shod) at a self-selected speed over 2 in-ground force plates.

MAIN OUTCOME MEASURE(S)

Three-dimensional GRFs, lower extremity joint angles, internal joint moments, joint powers, and activation amplitudes of 6 muscles were recorded during stance.

RESULTS

Compared with the control group, the CAI group demonstrated (1) increased plantar flexion or decreased dorsiflexion, increased inversion or decreased eversion, decreased knee flexion, decreased knee abduction, and increased hip-flexion angles; (2) increased or decreased inversion, increased plantar flexion, decreased knee extension, decreased knee abduction, and increased hip-extension moments; (3) increased vertical, braking, and propulsive GRFs; (4) increased hip eccentric and concentric power; and (5) altered muscle activation in all 6 lower extremity muscles.

CONCLUSIONS

The CAI group demonstrated a hip-dominant strategy by limiting propulsive forces at the ankle while increasing force generation at the hip. The different walking neuromechanics exhibited by the CAI group could represent maladaptive strategies that developed after the initial sprain or an injurious gait pattern that may have predisposed the participants to their initial injuries. Increased joint loading and altered kinematics at the foot and ankle complex during initial stance could affect the long-term health of the ankle articular cartilage.

Tibialis posterior muscle pain effects on hip, knee and ankle gait mechanics

BACKGROUND

Tibialis posterior (TP) dysfunction is a common painful complication in patients with rheumatoid arthritis (RA), which can lead to the collapse of the medial longitudinal arch. Different theories have been developed to explain the causality of tibialis posterior dysfunction. In all these theories, pain is a central factor, and yet, it is uncertain to what extent pain causes the observed biomechanical alterations in the patients. The aim of this study was to investigate the effect of experimental tibialis posterior muscle pain on gait mechanics in healthy subjects.

METHODS

Twelve healthy subjects were recruited for this randomized crossover study. Experimental pain was induced by ultrasound-guided injection of 1 mL hypertonic saline into the upper part of the right tibialis posterior muscle with the use of isotonic saline as non-pain-inducing control. Subsequently, kinematic data during three self-paced over ground walking for each condition were collected. Ground reaction forces and external moments were measured from force plates installed in the floor. Painful areas were evaluated using body charts and pain intensity scoring via a verbal numerical rating scale.

FINDINGS

Decreased hip internal rotation was observed during the pain condition at the end of the stance phase. There were no changes in gait velocity and duration of stand phase between the pain and no pain conditions. Reduced external joint moment was found for external knee rotation and for external hip rotation.

INTERPRETATION

The study has demonstrated that induced pain in the TP muscle evokes kinematic alteration in the hip and the knee joints, but not in the ankle, which suggest an underlying early stage joint compensatory mechanism. These findings suggest the need to include those joints in current physical evaluations of tibialis posterior dysfunction.

Kinetic Compensations due to Chronic Ankle Instability during Landing and Jumping

INTRODUCTION

Skeletal muscles absorb and transfer kinetic energy during landing and jumping, which are common requirements of various forms of physical activity. Chronic ankle instability (CAI) is associated with impaired neuromuscular control and dynamic stability of the lower extremity. Little is known regarding an intralimb, lower-extremity joint coordination of kinetics during landing and jumping for CAI patients. We investigated the effect of CAI on lower-extremity joint stiffness and kinetic and energetic patterns across the ground contact phase of landing and jumping.

METHODS

One hundred CAI patients and 100 matched able-bodied controls performed five trials of a landing and jumping task (a maximal vertical forward jump, landing on a force plate with the test leg only, and immediate lateral jump toward the contralateral side). Functional analyses of variance and independent t-tests were used to evaluate between-group differences for lower-extremity net internal joint moment, power, and stiffness throughout the entire ground contact phase of landing and jumping.

RESULTS

Relative to the control group, the CAI group revealed (i) reduced plantarflexion and knee extension and increased hip extension moments; (ii) reduced ankle and knee eccentric and concentric power, and increased hip eccentric and concentric power, and (iii) reduced ankle and knee joint stiffness and increased hip joint stiffness during the task.

CONCLUSIONS

CAI patients seemed to use a hip-dominant strategy by increasing the hip extension moment, stiffness, and eccentric and concentric power during landing and jumping. This apparent compensation may be due to decreased capabilities to produce sufficient joint moment, stiffness, and power at the ankle and knee. These differences might have injury risk and performance implications.

Walking mechanics for patellofemoral pain subjects with similar self-reported pain levels can differ based upon neuromuscular activation

Patellofemoral pain (PFP) is often studied on subjects who are classified using only self-reported data. Neuromuscular activation influences movement mechanics for PFP subjects, but is not likely to be self-reported. We compared lower-extremity mechanics, during a common movement (walking), between two subdivisions of a group of PFP subjects that were similar, based on common self-report tools, but different, based on a common objective measure of quadriceps activation. Our intent was to highlight the importance of objectively considering neuromuscular activation when researching PFP movement mechanics. Thirty similar PFP research subjects (based on four common self-report tools) were divided into two subdivisions, based on different quadriceps central activation ratios (CAR): a quadriceps deficit (QD; CAR <0.95) group and a no quadriceps deficit (NQD; CAR ≥0.95) group. All subjects in both groups performed five walking trials, while common mechanical characteristics were measured: 3D ground reaction force, and 3D joint kinematics and kinetics. Functional statistics were used to compare mechanical characteristics between the groups across the entire stance phase of gait (α=0.05). Numerous differences were found between the two groups for ground reaction force, and joint kinematics and kinetics. For example, the NQD group exhibited 5% greater vertical ground reaction force at peak impact, and 5% less vertical ground reaction force during the unloading portion of stance, relative to the QD group. The results indicate that when researching movement mechanics associated with PFP, it is important to consider objectively-measured neuromuscular activation characteristics that are not likely to be self-reported by PFP subjects.