The responsiveness of three-dimensional knee accelerations used as an estimation of knee instability and loading transmission during gait in osteoarthritis patient's follow-up

Self-reported walking difficulty influences gait characteristics in patients with medial compartment knee osteoarthritis

BACKGROUND

To differentiate gait strategies per knee osteoarthritis and self-reported walking difficulty during self-selected regular and fast gait speeds. We hypothesize that knee osteoarthritis gait characteristics during self-selected regular and fast gait speeds will be most accentuated by the osteoarthritis and walking difficulty group, followed by osteoarthritis and no walking difficulty, and least in the control group.

METHODS

Prospective study of community-dwelling older adults (n = 39) who walk at functional speeds (≥1.0 m per second) were age and sex matched across the three groups. Gait strategies including knee excursion and moments, muscle activation and co-contraction, and limb dynamics (linear acceleration and jerk) were compared between groups during self-selected regular and fast gait speed trials. Significant group differences were defined as P < 0.05 and an effect size greater than small.

FINDINGS

Based on walking difficulty, adduction moments (P-range = 0.00-0.03; effect size range,r = 0.42-0.52) and lateral quadriceps-gastrocnemius co-activations (P = 0.01;r = 0.36) were significant during regular gait speeds; and extension (P = 0.03;d = 0.59) and adduction (P-range = 0.00-0.02;d = 0.86;r = 0.40) moments were significant during fast trials. Per knee osteoarthritis presence, adduction moment(P = 0.01;r = 0.49), medial-quadriceps (P = 0.00;d = 1.04;r = 0.61), lateral-hamstrings (P = 0.04;d = 0.55), medial-gastrocnemius (P = 0.02;r = 0.40), medial quadriceps-hamstrings (P = 0.02;r = 0.38), medial quadriceps-gastrocnemius (P = 0.00;r = 0.56), and all limb dynamics (P = 0.00-0.01;d = 1.13-1.18;r = 0.35-0.47) were significant during regular gait speeds. Extension excursion (P = 0.02;d = 0.63), adduction moment (P = 0.01;d = 0.85) and medial-quadriceps (P = 0.01;r = 0.38) were significant during fast trials.

INTERPRETATION

Many gait strategies during regular speeds that differ per walking difficulty and knee osteoarthritis attenuated at fast speeds. Perhaps gait training at fast speeds for those with knee osteoarthritis related walking difficulty is biomechanically and functionally beneficial.

The Relationship Between Changes in Movement and Activity Limitation or Pain in People With Knee Osteoarthritis: A Systematic Review

OBJECTIVE

To report whether changes in knee joint movement parameters recorded during functional activities relate to change in activity limitation or pain after an exercise intervention in people with knee osteoarthritis (OA).

DESIGN

Etiology systematic review.

LITERATURE SEARCH

Four databases (MEDLINE, Embase, CINAHL, and AMED) were searched up to January 22, 2021.

STUDY SELECTION CRITERIA

Randomized controlled trials or cohort studies of exercise interventions for people with knee OA that assessed change in knee joint movement parameters (moments, kinematics, or muscle activity) and clinical outcomes (activity limitation or pain).

DATA SYNTHESIS

A descriptive synthesis of functional activities, movement parameters, and clinical outcomes.

RESULTS

From 3182 articles, 22 studies met the inclusion criteria, and almost all were of low quality. Gait was the only investigated functional activity. After exercise, gait parameters changed 26% of the time, and clinical outcomes improved 90% of the time. A relationship between group-level changes in gait parameters and clinical outcomes occurred 24.5% of the time. Two studies directly investigated an individual-level relationship, reporting only 1 significant association out of 8 correlations tested.

CONCLUSION

Most studies reported no change in gait-related movement parameters despite improvement in clinical outcomes, challenging the belief that changing movement parameters is always clinically important in people with knee OA. J Orthop Sports Phys Ther 2021;51(10):492-502. doi:10.2519/jospt.2021.10418.

Objective parameters to measure (in)stability of the knee joint during gait: A review of literature

BACKGROUND

Instability of the knee joint during gait is frequently reported by patients with knee osteoarthritis or an anterior cruciate ligament rupture. The assessment of instability in clinical practice and clinical research studies mainly relies on self-reporting. Alternatively, parameters measured with gait analysis have been explored as suitable objective indicators of dynamic knee (in)stability.

RESEARCH QUESTION

This literature review aimed to establish an inventory of objective parameters of knee stability during gait.

METHODS

Five electronic databases (Pubmed, Embase, Cochrane, Cinahl and SPORTDiscuss) were systematically searched, with keywords concerning knee, stability and gait. Eligible studies used an objective parameter(s) to assess knee (in)stability during gait, being stated in the introduction or methods section. Out of 10717 studies, 89 studies were considered eligible.

RESULTS

Fourteen different patient populations were investigated with kinematic, kinetic and/or electromyography measurements during (challenged) gait. Thirty-three possible objective parameters were identified for knee stability, of which the majority was based on kinematic (14 parameters) or electromyography (12 parameters) measurements. Thirty-nine studies used challenged gait (i.e. external perturbations, downhill walking) to provoke knee joint instability. Limited or conflicting results were reported on the validity of the 33 parameters.

SIGNIFICANCE

In conclusion, a large number of different candidates for an objective knee stability gait parameter were found in literature, all without compelling evidence. A clear conceptual definition for dynamic knee joint stability is lacking, for which we suggest : "The capacity to respond to a challenge during gait within the natural boundaries of the knee". Furthermore biomechanical gait laboratory protocols should be harmonized, to enable future developments on clinically relevant measure(s) of knee stability during gait.

Exciting perspectives for Translational Myology in the Abstracts of the 2018Spring PaduaMuscleDays: Giovanni Salviati Memorial - Chapter IV - Abstracts of March 17, 2018

Myologists working in Padua (Italy) were able to continue a half-century tradition of studies of skeletal muscles, that started with a research on fever, specifically if and how skeletal muscle contribute to it by burning bacterial toxin. Beside main publications in high-impact-factor journals by Padua myologists, I hope to convince readers (and myself) of the relevance of the editing Basic and Applied Myology (BAM), retitled from 2010 European Journal of Translational Myology (EJTM), of the institution of the Interdepartmental Research Center of Myology of the University of Padova (CIR-Myo), and of a long series of International Conferences organized in Euganei Hills and Padova, that is, the PaduaMuscleDays. The 2018Spring PaduaMuscleDays (2018SpPMD), were held in Euganei Hills and Padua (Italy), in March 14-17, and were dedicated to Giovanni Salviati. The main event of the “Giovanni Salviati Memorial”, was held in the Aula Guariento, Accademia Galileiana di Scienze, Lettere ed Arti of Padua to honor a beloved friend and excellent scientist 20 years after his premature passing. Using the words of Prof. Nicola Rizzuto, we all share his believe that Giovanni “will be remembered not only for his talent and originality as a biochemist, but also for his unassuming and humanistic personality, a rare quality in highly successful people like Giovanni. The best way to remember such a person is to gather pupils and colleagues, who shared with him the same scientific interests and ask them to discuss recent advances in their own fields, just as Giovanni have liked to do”. Since Giovanni’s friends sent many abstracts still influenced by their previous collaboration with him, all the Sessions of the 2018SpPMD reflect both to the research aims of Giovanni Salviati and the traditional topics of the PaduaMuscleDays, that is, basics and applications of physical, molecular and cellular strategies to maintain or recover functions of skeletal muscles. The translational researches summarized in the 2018SpPMD Abstracts are at the appropriate high level to attract endorsement of Ethical Committees, the interest of International Granting Agencies and approval for publication in top quality international journals. The abstracts of the presentations of the March 16, 2018 Padua Muscle Day and those of the remaining Posters are listed in this chapter IV. The Author Index of the 2018Spring PaduaMuscleDays follows at page 78.

Exercise and osteoarthritis: cause and effects

Osteoarthritis (OA) is a common chronic joint condition predominantly affecting the knee, hip, and hand joints. Exercise plays a role in the development and treatment of OA but most of the literature in this area relates to knee OA. While studies indicate that exercise and physical activity have a generally positive effect on healthy cartilage metrics, depending upon the type of the activity and its intensity, the risk of OA development does appear to be moderately increased with sporting participation. In particular, joint injury associated with sports participation may be largely responsible for this increased risk of OA with sport. Various repetitive occupational tasks are also linked to greater likelihood of OA development. There are a number of physical impairments associated with OA including pain, muscle weakness and altered muscle function, reduced proprioception and postural control, joint instability, restricted range of motion, and lower aerobic fitness. These can result directly from the OA pathological process and/or indirectly as a result of factors such as pain, effusion, and reduced activity levels. These impairments and their underlying physiology are often targeted by exercise interventions and evidence generally shows that many of these can be modified by specific exercise. There is currently little clinical trial evidence to show that exercise can alter mechanical load and structural disease progression in those with established OA, although a number of impairments, that are amenable to change with exercise, appears to be associated with increased mechanical load and/or disease progression in longitudinal studies.

Does knee alignment influence gait in patients with severe knee osteoarthritis?

BACKGROUND

Patients with knee osteoarthritis present an altered gait pattern. Amongst many factors, the lower limb alignment (varus, valgus) has been identified as an important risk factor for the progression of knee osteoarthritis. Among the large number of studies on knee osteoarthritis gait, only a few have included patients with a valgus deformity. The aims of this study were to determine how knee alignment influences full-body gait in patients with knee osteoarthritis and if knee malalignment is associated with pain and functional capacity.

METHODS

Sixty patients with severe knee osteoarthritis scheduled for a total knee arthroplasty were included in this study. Twenty-six subjects were recruited as the control group. The spatio-temporal parameters, three-dimensional full-body kinematics, and lower body kinetics were evaluated during a comfortable gait and compared between the groups. Pain and function were assessed with the WOMAC questionnaire.

FINDINGS

The full-body gait analysis demonstrated substantially different gait patterns and compensation mechanisms between the three groups. Patients with varus knee alignment significantly augmented their trunk movements in sagittal and frontal planes compared to patients with a valgus knee. In addition, patients with a valgus knee reported lower pain and lower functional deficits compared to patients with a varus knee.

INTERPRETATION

We found that gait compensations were significantly influenced by lower limb alignment. These new insights related to different knee osteoarthritis gait patterns might help in the understanding of gait compensation behaviours prior to total knee arthroplasty and better manage the strategies of rehabilitation following surgery.

Sit-to-stand alterations in advanced knee osteoarthritis

This study investigated the full-body strategies utilized during a sit-to-stand (STS) task in patients with knee osteoarthritis (OA) and the association between STS alterations and clinical measurements. Twenty-five patients with advanced knee OA and twenty healthy elderly adults were recruited to participate in this study. Patients were asked to stand up from a chair four times without using their arms. A 3D motion analysis system was used to capture the full-body kinematics during the task. Two force plates were used to capture the forces under each leg. The following parameters were investigated in the knee OA group and compared with the control group: the time to realize STS, the force ratio between both limbs, the knee and hip kinetics and the trunk kinematics. The pain and functional capacity were obtained from the WOMAC. The results showed that patients with knee OA put 10% additional weight on the contralateral side when compared with the symmetrical strategy of the control group. Patients with knee OA showed a significantly lower knee flexion moment (0.51 Nm/kg vs. 0.72 Nm/kg), a higher maximal trunk flexion (46.4° vs. 37.5°), and a higher lateral trunk lean on the contralateral side (2.4° vs. 0.9°) when compared with the control group. The main correlations were found between pain and the averaged time to complete the STS task (r=0.55). With the quantification of the full-body mechanisms utilized during the STS task, which includes both distal and proximal compensations, our study brings new insights, leading to a better understanding of the functional alterations in patients with advanced knee OA.

The KneeKG system: a review of the literature

PURPOSE

Accurately quantifying knee joint motion is not simple. Skin movement over the medial and lateral femoral condyles is the greatest obstacle to obtaining accurate movement data non-invasively. The KneeKG™ system was developed with the objective of providing high reliability movement analysis. The goal of this manuscript is to review the technical details, clinical evidence, and potential applications of this system for evaluation of rotational knee laxity.

METHODS

A comprehensive review of the MEDLINE database was carried out to identify all clinical and biomechanical studies related to KneeKG™ system.

RESULTS

The KneeKG™ system non-invasively quantifies knee abduction/adduction, axial rotation, and relative translation of the tibia and femur. The accuracy and reproducibility of the system have been assessed. The average accuracy of the acquisition is 0.4° for abduction/adduction, 2.3° for axial rotation, 2.4 mm for anteroposterior translation, and 1.1 mm for axial translation. This clinical tool enables an accurate and objective assessment of the tri-planar function of the knee joint. The measured biomechanical parameters are sensitive to changes in gait due to knee osteoarthritis and ACL deficiency.

CONCLUSION

The KneeKG™ system provides reliable movement analysis. This system has the potential to improve understanding the biomechanical consequences of trauma or degenerative changes of the knee as well as more accurately quantify rotational laxity as detected by a positive pivot-shift test.

Association of lower muscle strength with self-reported knee instability in osteoarthritis of the knee: results from the Amsterdam Osteoarthritis cohort

OBJECTIVE

To determine whether muscle strength, proprioceptive accuracy, and laxity are associated with self-reported knee instability in a large cohort of knee osteoarthritis (OA) patients, and to investigate whether muscle strength may compensate for impairment in proprioceptive accuracy or laxity, in order to maintain knee stability.

METHODS

Data from 283 knee OA patients from the Amsterdam Osteoarthritis cohort were used. Univariable and multivariable logistic regression analyses were performed to assess the association between muscle strength, proprioceptive accuracy (motion sense), frontal plane varus-valgus laxity, and self-reported knee instability. Additionally, effect modification between muscle strength and proprioceptive accuracy and between muscle strength and laxity was determined.

RESULTS

Self-reported knee instability was present in 67% of the knee OA patients and mainly occurred during walking. Lower muscle strength was significantly associated with the presence of self-reported knee instability, even after adjusting for relevant confounding. Impaired proprioceptive accuracy and high laxity were not associated with self-reported knee instability. No effect modification between muscle strength and proprioceptive accuracy or laxity was found.

CONCLUSION

Lower muscle strength is strongly associated with self-reported knee instability in knee OA patients, while impairments in proprioceptive accuracy and laxity are not. A compensatory role of muscle strength for impaired proprioceptive accuracy or high laxity, in order to stabilize the knee, could not be demonstrated.

Evaluation of unipodal stance in knee osteoarthritis patients using knee accelerations and center of pressure

OBJECTIVE

This study aims to compare knee joint instability and postural impairments during the performance of a unipodal stance task between patients having knee osteoarthritis (OA) and healthy elderly subjects using knee accelerations and center of pressure (COP) measurements.

MATERIALS AND METHODS

Twenty patients with medial knee OA and nine healthy individuals participated in this study. Three-dimensional (3D) knee joint accelerations and COP were measured during unipodal stance. The range and the root mean square (RMS) were extracted from medial lateral (ML) and anterior-posterior (AP) knee accelerations, whereas sway area, velocity, and ML and AP ranges were measured from the COP. The average parameters of three trials for each subject were compared between groups.

RESULTS

Results show that knee OA patients exhibited a significantly higher range of knee acceleration in both ML (0.22±0.08 g vs 0.15±0.05 g) and AP (0.17±0.06 g vs 0.06±0.01 g) directions and a lower COP velocity (136.6±22.3 mm/s vs 157.6±18.4 mm/s) than did the healthy age-matched group. Significant correlations between the COP and knee acceleration parameters were also obtained.

CONCLUSIONS

This study confirmed that patients with knee OA displayed greater body sway than did able-bodied subjects. Moreover, using an accelerometric-based method, this study highlighted the higher knee joint instability in the frontal and sagittal planes in knee OA patients compared with able-bodied subjects during a unipodal standing task.

Effects of physiotherapy treatment on knee osteoarthritis gait data using principal component analysis

BACKGROUND

Interpreting gait data is challenging due to intersubject variability observed in the gait pattern of both normal and pathological populations. The objective of this study was to investigate the impact of using principal component analysis for grouping knee osteoarthritis (OA) patients' gait data in more homogeneous groups when studying the effect of a physiotherapy treatment.

METHODS

Three-dimensional (3D) knee kinematic and kinetic data were recorded during the gait of 29 participants diagnosed with knee OA before and after they received 12 weeks of physiotherapy treatment. Principal component analysis was applied to extract groups of knee flexion/extension, adduction/abduction and internal/external rotation angle and moment data. The treatment's effect on parameters of interest was assessed using paired t-tests performed before and after grouping the knee kinematic data.

FINDINGS

Increased quadriceps and hamstring strength was observed following treatment (P<0.05). Except for the knee flexion/extension angle, two different groups (G(1) and G(2)) were extracted from the angle and moment data. When pre- and post-treatment analyses were performed considering the groups, participants exhibiting a G(2) knee moment pattern demonstrated a greater first peak flexion moment, lower adduction moment impulse and smaller rotation angle range post-treatment (P<0.05). When pre- and post-treatment comparisons were performed without grouping, the data showed no treatment effect.

INTERPRETATION

The results of the present study suggest that the effect of physiotherapy on gait mechanics of knee osteoarthritis patients may be masked or underestimated if kinematic data are not separated into more homogeneous groups when performing pre- and post-treatment comparisons.