Trunk Biomechanics in Individuals with Knee Disorders: A Systematic Review with Evidence Gap Map and Meta-analysis

Do bilateral deficits in hop for distance performance occur concomitantly with bilateral movement differences in people with patellofemoral pain? A cross-sectional investigation with between-group and -limb comparisons

BACKGROUND

People with patellofemoral pain (PFP) may have bilateral deficits in hop for distance test (SLHD) performance, whereas the worsening performance of the pain-free or less painful limbs suggests that bilateral movement differences may occur. While clinicians may not be aware of bilateral movement differences that may be employed during the clinical assessment of SLHD performance (e.g., excessive trunk flexion, lower knee, hip and ankle angles), their suboptimal investigation may overestimate function and favor long-term sequelae.

RESEARCH QUESTION

Do people with PFP exhibit bilateral differences in trunk and lower limb movements as well as bilateral deficits in SLHD performance compared to pain-free controls?

METHODS

We captured three-dimensional motion of 26 adults with PFP and 22 controls during testing and calculated trunk and lower limb sagittal plane kinematics, total concentric and eccentric work, and hip, knee, and ankle work contributions during the jumping and landing phases of the SLHD. We also calculated vertical ground reaction forces during the landing phase and compared between-group and -limb differences using independent and paired t-tests.

RESULTS

People with PFP demonstrated bilateral deficits in SLHD performance (medium effects; p = .028-.050) and lower peak vertical ground reaction force values (medium-to-large effects; p = .006-.012) as compared to controls. No other between-group or -limb differences were identified.

SIGNIFICANCE

Bilateral deficits in SLHD performance seem to occur independently of movement differences in people with PFP, as they presented shorter distance but no differences in sagittal plane biomechanical patterns.

A biokinetic approach in primary knee osteoarthritis prevention and management-exploring movement profiles and kinetic chain interactions: Current concepts

Knee osteoarthritis (OA) is a chronic disease characterized by increasing prevalence and significant physical, psychological, and economic burdens. Despite extensive research, the definition, risk factors, and effective cost-efficient treatments for knee OA remain unclear. This article aims to revisit primary knee OA, understanding its etiology, and focusing on prevention and individualized nonoperative treatment modalities. This study reviews various aspects of knee OA, including its global prevalence, economic impact, and current treatment strategies. It explores the role of mechanical loading pathways in the disease's onset, highlighting the importance of considering not only the knee but the entire kinetic chain in diagnosis and treatment. Also, it discusses knee anatomy and biomechanics during functional activities, emphasizing the role of neuromuscular control and the influence of proximal and distal joints on knee health. Current treatments focus mainly on symptom management, with limited success in disease prevention and curative interventions. This review underlines the importance of understanding the biomechanical risk factors contributing to knee OA and the necessity of individualized interventions based on biokinetic profile analysis. Knee OA management and prevention necessitate a paradigm shift from viewing it as a localized knee disease to recognizing related mechanical overloads of the human complex motion system. Identifying individual inductive elements is paramount for effective knee OA prevention, management, and rehabilitation. Future research should endeavor to identify movement profile subgroups to establish an early-stage prognosis and the impact of interventions for each group. LEVEL OF EVIDENCE V: Expert opinion based on nonsystematic review.

Muscle Tone and Stiffness Comparison in Ambulatory Children With Unilateral Spastic Cerebral Palsy: Implications for Postural Balance and Functional Mobility

OBJECTIVES

To compare muscle tone and stiffness in ambulatory children with unilateral spastic cerebral palsy (UCP) with typically developing peers and explore their relationship with postural balance and functional mobility.

METHODS

Forty ambulatory children with UCP and age-matched typically developing peers were assessed for tone and stiffness of lumbar spinal extensors, gastrocnemius, and hamstring muscles using a myotonometer. Functional mobility was evaluated with the 2-Minute Walk Test, and the Timed Up and Go Test, while postural balance was evaluated using the Pediatric Balance Scale and the Trunk Control Measurement Scale (TCMS).

RESULTS

The gastrocnemius muscle tone and stiffness were higher on the affected side in UCP compared with the less affected side and typically developing peers (P < .05). Lumbar spinal extensor tone correlated with improved Trunk Control Measurement Scale scores (P = .003). The gastrocnemius and hamstring muscles' tone and stiffness did not significantly affect functional mobility measures in UCP (P > .05).

CONCLUSIONS

Our study highlights the importance of achieving muscle symmetry, particularly in the plantar flexors, for functional mobility in UCP children. While differences in ankle and knee muscle biomechanics were observed, they didn't significantly impact functional mobility or postural balance. Symmetry in lumbar spinal extensor biomechanics correlated with better outcomes, emphasizing the crucial role of trunk control in rehabilitation strategies for ambulatory children with UCP.

People With Patellofemoral Pain Have Bilateral Deficits in Physical Performance Regardless of Pain Laterality

CONTEXT

People with patellofemoral pain (PFP) may have lower performance during the forward step-down and single-leg hop with their painful (unilateral complaints) or most painful (bilateral complaints) limb when compared with pain-free controls. However, no authors have investigated the appropriateness of using the pain-free or less painful limb as a reference standard in clinical practice or whether deficits might be present depending on the laterality of pain.

OBJECTIVE

To compare performance scores and proportion of side-to-side limb symmetry during the forward step-down and single-leg hop tests among people with unilateral and bilateral PFP and pain-free controls.

DESIGN

Cross-sectional study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

Fifty-two young adults (18-35 years old) with unilateral PFP, 72 with bilateral PFP, and 76 controls.

MAIN OUTCOME MEASURE(S)

Group × limb interactions on performance during the step-down (repetitions) and single-leg hop (distance [cm] normalized by the limb length) tests were investigated using a repeated-measures analysis of covariance controlling for sex. Pairwise comparisons were interpreted using effect sizes. A χ2 test was used to compare the proportion of symmetry/asymmetry (cutoff point of ≥90% for symmetry indices) across groups and tests.

RESULTS

Main effects for groups (small to medium effects) but not limbs indicated lower performance of both limbs of individuals with unilateral and bilateral PFP than controls during forward step-down and single-leg hop tests. No significant differences for the proportion of symmetry/asymmetry were identified across groups (P ≥.05), which further suggests an impaired physical performance of the contralateral limb.

CONCLUSIONS

Our results indicate bilateral deficits in the physical performance of people with unilateral and bilateral PFP when compared with pain-free controls during the forward step-down and single-leg hop tests. Limb symmetry indices greater than 90% should be interpreted with caution, as they may overstate physical performance by not assuming bilateral deficits.

Relationship Between the Results of the Landing Error Scoring System and Trunk Muscle Thickness

Background

A landing error scoring system (LESS) is widely used to evaluate landing maneuvers. Poor landing maneuvers, such as lateral bending of the trunk, are thought to be associated with a risk of lower-extremity injury. However, no studies have examined the association between landing and trunk muscle function, which is associated with a high risk of lower-extremity injury.

Hypothesis/Purpose

This study examined whether an association exists between landing movements and a high risk of lower-extremity injury and trunk muscle function. It was hypothesized that athletes with poor activation of deep trunk muscle (transversus abdominis and internal oblique) would have lower LESS scores.

Study Design

Cross-sectional study.

Methods

The trunk muscle thickness at rest and during the plank was measured using ultrasonography. The percent of change in muscle thickness (during plank/at rest) was calculated. The LESS was measured using the Physimax. Based on the LESS scores, patients were divided into high- (LESS > 6) and low-risk (5 > LESS) groups for lower extremity injury. The relationship between the high-risk group and trunk muscle thickness was examined using a stepwise regression analysis.

Results

The high-risk group had significantly lower muscle thicknesses of the transversus abdominis (p=0.02) and transversus abdominis plus internal oblique abdominis (p=0.03) muscles during the plank. Additionally, the high-risk group showed significantly lower percent of change in muscle thickness of the internal oblique (p=0.02) and transversus abdominis plus internal oblique (p=0.01) muscles. Only the percentage of change in the thickness of the internal oblique and transverse abdominal muscles was extracted from the regression as a factor.

Conclusion

The findings indicated that athletes with landing movements and a high risk of injury, as determined based on the LESS results, had low trunk muscle function, and a relationship was observed between the change in thickness of transversus abdominis and internal oblique abdominis muscles.

Level of Evidence

3B.

Exploratory study of the lateral body sway predictability as frame of reference for gait rehabilitation following a total knee arthroplasty

AIMS

The aim of the present study was to investigate whether the predictability of fronto-parallel trunk rotations (lateral body sway) could serve as a frame of reference to monitor recovery after total knee arthroplasty (TKA).

METHODS

Before surgery, 11 TKA patients were asked to perform a treadmill walking task at three different speeds. In addition, their gait abilities were scored on three standard clinical walking tests. The treadmill walking task was repeated at three different timepoints following surgery, i.e., at 3, 6 and 12 months post-TKA. The movements of the trunk were digitized with an inertial sensor to capture the amplitude and the sample entropy (SEn) of the lateral body sway that were evaluated in separate ANOVAs.

RESULTS

Before surgery the TKA group showed larger body sway (P = 0.025) with smaller SEn values (P = 0.038), which both restored to levels of healthy adults in the 12 months following surgery. Systematic correlations between the SEn values and the clinical test scores were found.

CONCLUSIONS

The current findings show that movement behavior of the trunk in the fronto-parallel plane was affected by knee osteoarthritis and suggest that the predictability of the lateral body sway may serve as an index of recovery after TKA.

Efficacy of Mulligan joint mobilizations and trunk stabilization exercises versus isometric knee strengthening in the management of knee osteoarthritis: a randomized controlled trial

BACKGROUND

Knee osteoarthritis (KOA) progression is often influenced by biomechanical factors. Biomechanical interventions, such as Trunk stabilization exercise (TSE) and Mulligan joint mobilization (MWM), may offer relief from KOA symptoms and potentially slow disease progression. However, the comparative efficacy of these therapies remains uncertain. This study aimed to compare the efficacy of TSE, Mulligan joint mobilization, and isometric knee strengthening (KSE) on disability, pain severity, and aerobic exercise capacity in patients with KOA.

METHODOLOGY

A randomized controlled trial (RCT) with three intervention groups was conducted between September 2020 to February 2021. The study enrolled adults aged between 40 and 60 years with a confirmed KOA diagnosis recruited from the physical therapy clinic of the Sindh Institute of Physical Medicine and Rehabilitation, Pakistan. Participants were randomly assigned to receive 24 sessions of either TSE, MWM, or KSE. The knee's functionality was assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS), pain on a visual analogue scale (VAS), and two objective functional tests-the 6-minute walk test (6MWT) and the 11-stair climb test (SCT). These assessments were conducted at baseline, the third week, and the sixth week. Changes in outcome measures were analyzed using a mixed-design ANOVA with Bonferroni post-hoc analysis, with statistical significance set at a p-value < 0.05.

RESULT

Of the 60 participants, 22 (36.7%) were females, and 38 (63.3%) were males. Within-group analysis revealed a significant improvement in all outcome measures at the third week (p < 0.05) and sixth week (p < 0.05). Notably, the TSE group exhibited a greater reduction in mean difference (M.D) in VAS scores than the MWM and KSE groups across various measures in the third week. At rest, during stair ascent, and descent, the TSE group showed significant improvements in VAS scores: MWM (-2.05; -1.94; -1.94), TSE (-2.38; -2.5; -2.5), KSE (-1.05; -0.63; -0.63). Additionally, during sub-maximal exercise capacity assessment, the TSE group showed greater improvement (MWM 12.89; TSE 22.68; KSE 7.89), as well as in Knee Injury and Osteoarthritis Outcome Score for activities of daily living (KOOS-ADL) (MWM 20.84; TSE 28.84; KSE 12.68), and KOOS-pain (MWM 24.84; TSE 27.77; KSE 5.77) at the third-week assessment (p < 0.05). The TSE group demonstrated significant improvements (p < 0.05) across various measures in the sixth week. Specifically, improvements were observed in VAS scores at rest (MWM - 4.15; TSE - 4.42; KSE - 3.78), during stair ascent (MWM - 3.89; TSE - 4.88; KSE - 3.56) and descent (MWM - 3.78; TSE - 4.05; KSE - 2.94). Furthermore, significant improvements were noted in the stair climb test (MWM - 7.05; TSE - 7.16; KSE - 4.21), 6-minute walk test (6MWT) (MWM 22.42; TSE 37.6; KSE 13.84), KOOS-pain (MWM 41.47; TSE 49.11; KSE 28.73), and KOOS-ADL (MWM 40.31; TSE 50.57; KSE 26.05).

CONCLUSION

In this study in patients with KOA, TSE had greater efficacy compared to MWM and KSE in enhancing functional levels, reducing pain, improving sub-maximal exercise capacity, and performance on the stair climb test. Importantly, mean scores between the groups, particularly in the TSE group, reached the minimally important level, particularly in key areas such as pain, functional levels, sub-maximal exercise capacity, and stair climb performance. Clinicians should consider the significant pain reduction, improved functionality, and enhanced exercise capacity demonstrated by TSE, indicating its potential as a valuable therapeutic choice for individuals with KOA.

TRIAL NO

ClinicalTrials.gov = NCT04099017 23/9/2019.

Patellar Tendon Load Progression during Rehabilitation Exercises: Implications for the Treatment of Patellar Tendon Injuries

PURPOSE

This study aimed to evaluate patellar tendon loading profiles (loading index, based on loading peak, loading impulse, and loading rate) of rehabilitation exercises to develop clinical guidelines to incrementally increase the rate and magnitude of patellar tendon loading during rehabilitation.

METHODS

Twenty healthy adults (10 females/10 males, 25.9 ± 5.7 yr) performed 35 rehabilitation exercises, including different variations of squats, lunge, jumps, hops, landings, running, and sports specific tasks. Kinematic and kinetic data were collected, and a patellar tendon loading index was determined for each exercise using a weighted sum of loading peak, loading rate, and cumulative loading impulse. Then the exercises were ranked, according to the loading index, into tier 1 (loading index ≤0.33), tier 2 (0.33 < loading index <0.66), and tier 3 (loading index ≥0.66).

RESULTS

The single-leg decline squat showed the highest loading index (0.747). Other tier 3 exercises included single-leg forward hop (0.666), single-leg countermovement jump (0.711), and running cut (0.725). The Spanish squat was categorized as a tier 2 exercise (0.563), as was running (0.612), double-leg countermovement jump (0.610), single-leg drop vertical jump (0.599), single-leg full squat (0.580), double-leg drop vertical jump (0.563), lunge (0.471), double-leg full squat (0.428), single-leg 60° squat (0.411), and Bulgarian squat (0.406). Tier 1 exercises included 20 cm step up (0.187), 20 cm step down (0.288), 30 cm step up (0.321), and double-leg 60° squat (0.224).

CONCLUSIONS

Three patellar tendon loading tiers were established based on a combination of loading peak, loading impulse, and loading rate. Clinicians may use these loading tiers as a guide to progressively increase patellar tendon loading during the rehabilitation of patients with patellar tendon disorders and after anterior cruciate ligament reconstruction using the bone-patellar tendon-bone graft.

Detection of kinematic abnormalities in persons with knee osteoarthritis using markerless motion capture during functional movement screen and daily activities

Background: The functional movement screen (FMS) has been used to identify deficiencies in neuromuscular capabilities and balance among athletes. However, its effectiveness in detecting movement anomalies within the population afflicted by knee osteoarthritis (KOA), particularly through the application of a family-oriented objective assessment technique, remains unexplored. The objective of this study is to investigate the sensitivity of the FMS and daily activities in identifying kinematic abnormalities in KOA people employing a markerless motion capture system. Methods: A total of 45 persons, presenting various Kellgren-Lawrence grades of KOA, along with 15 healthy controls, completed five tasks of the FMS (deep squat, hurdle step, and in-line lunge) and daily activities (walking and sit-to-stand), which were recorded using the markerless motion capture system. The kinematic waveforms and discrete parameters were subjected to comparative analysis. Results: Notably, the FMS exhibited greater sensitivity compared to daily activities, with knee flexion, trunk sagittal, and trunk frontal angles during in-line lunge emerging as the most responsive indicators. Conclusion: The knee flexion, trunk sagittal, and trunk frontal angles during in-line lunge assessed via the markerless motion capture technique hold promise as potential indicators for the objective assessment of KOA.

Effect of different isometric trunk extension intensities on the muscle stiffness of the lumbar and lower limbs

Purpose: To investigate the effect of isometric prone trunk extension (IPTE) contraction intensity on the stiffness of erector spinae (ES), semitendinosus (ST), biceps femoris (BF), and gastrocnemius muscles to understand the overall muscle mechanical behavior during IPTE and to explore the mechanisms of oordinated contraction of the body kinetic chain. Methods: Twenty healthy females were recruited, and participants underwent IPTE at three contraction intensities, i.e., 0% maximum voluntary isometric contraction (MVIC), 30% MVIC, and 60% MVIC, and muscle stiffness was measured using MyotonPRO. Results: Muscle stiffness was moderately to strongly positively correlated with contraction intensity (r = 0.408-0.655, p < 0.001). The percentage increase in stiffness at low intensity was much greater in ES than in lower limb muscles and greater in ST and BF than in gastrocnemius, whereas at moderate intensity, the percentage increase in stiffness decreased in all muscles, and the percentage increase in stiffness in ES was lower than that in ST. There was a moderate to strong positive correlation between ES stiffness variation and ST (r = 0.758-0.902, p < 0.001), BF (r = 0.454-0.515, p < 0.05), MG (r = 0.643-0.652, p < 0.01), LG (r = 0.659-0.897, p < 0.01). Conclusion: IPTE significantly affected the stiffness of lumbar and lower limb muscles, and low-intensity IPTE activated the ES more efficiently. There were significant coordinated muscle contractions between ES, ST, and LG. This provides preliminary evidence for exploring the overall modulation pattern of the lumbar and lower limb muscles' kinetic chains. In future studies, we will combine other stiffness assessment methods (such as Magnetic Resonance Elastography, Shear Wave Elastography, or electromyography) to corroborate our findings.