Lower Limb Loading Research Articles

Assessment of Asymmetrical Lower Limb Loading in the Short-Track Speed Skaters

Background. Short-track speed skaters who regularly participate in training are exposed to the occurrence of asymmetry in the lower limb loading. 
 Objective. The study aimed to assess the symmetry of the lower limb loading in short track skaters and the relationship between age, training experience and anthropometric variables and symmetry of lower limb loading.
 Methods. The examined group consisted of 20 short-track speed skaters (12 men and 8 women), and the control group comprised 28 university students (14 men and 14 women). Two scales were used to assess the symmetry of lower limb loading, and the lower limb's loading symmetry index (LSI) was calculated. 
 Results. In the studied groups 65% of skaters and 82% of students have LSI within the normal range. Most short-track speed skaters (85%) put weight on the right lower limb, and there was no clear trend among students (p < 0.001). In the group of skaters, the majority of men (83%) properly loaded their lower limbs, compared to 37.5% of women (p = 0.036). In short-track speed skaters, positive correlations were found between LSI and the age and length of training.
 Conclusions. Long-term asymmetric loading of the lower limbs in short-track speed skaters causes the advantage of the load on the right lower limb and increases the asymmetry of the load on the lower limbs, especially in women.

Effects of four-week lower limb loading training with and without augmented feedback on mobility, walking device use, and falls among ambulatory individuals with spinal cord injury: a randomized controlled trial

Purpose To compare the effects of lower limb loading training (LLLT) with or without augmented loading feedback during stepping activity on mobility, walking device use, and falls among ambulatory individuals with chronic spinal cord injury (SCI). Study design Randomized controlled trial (assessor-blinded) with prospective fall data follow-up, clinical trial registration (NCT03254797). Methods Forty-four ambulatory participants (22 participants/group) were prospectively monitored for their baseline fall data over six months, with baseline assessments for their mobility and walking device used after six months. Then participants involved in the LLLT programs with or without loading feedback according to their groups for 30 min/day, 5 days/week, over 4 weeks. Mobility outcomes were re-assessed at week two and week four, with prospective fall data monitoring over six months, and mobility measured thereafter. Results Mobility outcomes of the participants were significantly improved from their baseline ability, especially in those who were trained using augmented feedback (the difference in main outcome, timed up and go, between the groups was 1.8 s; 95% confidence interval = 1.0–3.5s). Conclusions LLLT during stepping activity, especially with augmented loading feedback, could be applied effectively to promote mobility and safety of ambulatory individuals with chronic SCI (post-injury time of approximately four years).

Neuromechanical control of impact absorption during induced lower limb loading in individuals post-stroke

Decreased loading of the paretic lower limb and impaired weight transfer between limbs negatively impact balance control and forward progression during gait in individuals post-stroke. However, the biomechanical and neuromuscular control mechanisms underlying such impaired limb loading remain unclear, partly due to their tendency of avoiding bearing weight on the paretic limb during voluntary movement. Thus, an approach that forces individuals to more fully and rapidly load the paretic limb has been developed. The primary purpose of this study was to compare the neuromechanical responses at the ankle and knee during externally induced limb loading in people with chronic stroke versus able-bodied controls, and determine whether energy absorption capacity, measured during induced limb loading of the paretic limb, was associated with walking characteristics in individuals post-stroke. Results revealed reduced rate of energy absorption and dorsiflexion velocity at the ankle joint during induced limb loading in both the paretic and non-paretic side in individuals post-stroke compared to healthy controls. The co-contraction index was higher in the paretic ankle and knee joints compared to the non-paretic side. In addition, the rate of energy absorption at the paretic ankle joint during the induced limb loading was positively correlated with maximum walking speed and negatively correlated with double limb support duration. These findings demonstrated that deficits in ankle dorsiflexion velocity may limit the mechanical energy absorption capacity of the joint and thereby affect the lower limb loading process during gait following stroke.

The presence of a previous lower limb injury does not affect step asymmetry in elite basketball players: A prospective, longitudinal observational study

ABSTRACT This study investigates whether the presence of a previous lower limb injury influences “Lower limb asymmetry” (LLA) in elite basketball players. A prospective, longitudinal observational study was carried out with 13 players grouped based on lower limb injury history in the 3 months prior to the study (Injury = 7, non-injured = 6). A total of 68 measurements per player were collected over 3 months, using the “Inertial Measurement Unit (IMU)” device. The mean difference in, (i) % of step balance; (ii) the average of the number of impacts performed per minute during training and (iii) the player’s load was assessed. This intensive evaluation is in line with the assessment methodology proposed in the field of sports injury. Our results show no significant differences (p = 0.377) in the asymmetry of the step balance between players with/without a history of injury. However, there were differences when the player’s position was considered (p = 0.046). These findings confirm that the presence of a previous lower limb injury does not influence the asymmetry in lower limb step balance in male basketball players. For clinicians, the variables studied offer an indirect measurement of any capacity and/or deficit in the absorption of lower limb loads after an injury.

Quantification Of Limb Loading Asymmetries In Collegiate Basketball Players During Basketball Tasks

Lower extremity biomechanical asymmetries have been previously identified in basketball athletes during individual screening tasks. The amount of asymmetry that occurs during basketball-specific tasks is not as well understood. PURPOSE: To identify the extent of lower limb loading asymmetry, as measured by a wearable sensor, that occurs during basketball-specific tasks and to determine whether sex-differences in loading patterns exist between male and female basketball athletes. METHODS: Fifteen NCAA Division-I men’s (n: 7, height: 187.3 ± 15.2 cm, mass: 91.4 ± 20.9 kg) and women’s (n: 8, height: 175.5 ± 10.9 cm, mass: 73.8 ± 11.6 kg) basketball athletes participated in the study. Each participant wore an inertial measurement unit on the distal medial aspect of each tibia while completing a series of basketball-related tasks (i.e. drop vertical jump, single leg countermovement jump), and eight basketball-specific tasks (e.g. dribbling, shooting, cutting, sprinting) over the course of a 30-minute session. The average intensity of each impact as measured by tibial acceleration and impact load as a function of the number and intensity of impacts were used for analysis. 2 (side) x 2 (gender) repeated measures ANOVA with post-hoc independent t-tests were used to identify side-to-side asymmetries and sex differences in intensity and loading variables (α = 0.05). RESULTS: For all participants, there were no significant differences in average loading intensity (dominant limb (D): 10.4 ± 1.5 g, non-dominant limb (ND): 10.1 ± 1.5 g) or impact load (D: 6007 ± 1245 g, ND: 5720 ± 1033 g) between sides (p > 0.05). There were significant sex differences in the average intensity of loading such that female basketball players exhibited greater average loading than males in the dominant (M: 9.5 ± 1.0 g, F: 11.1 ± 1.5 g; p = 0.04) and non-dominant limb (M: 9.0 ± 0.8 g, F: 11.1 ± 1.4 g; p = 0.005). CONCLUSIONS: No significant loading asymmetries were identified in collegiate basketball players, warranting further study in a natural, non-simulated environment. Significant differences in loading were identified such that female basketball players had higher average loading than male basketball players, potentially due to differences in force attenuation strategies during running, cutting, jumping and landing.

"I'm More Comfortable with a Wide-Fit Shoe" The Footwear Needs and Preferences of Older Adults in Racket Sports.

Physical activity is important throughout the lifespan. Racket sports are popular with older adults and offer important social benefits. It is unknown how the physiologic changes attributable to aging affect lower limb loading during multidirectional sports and how this may influence footwear requirements. The purpose of this work was to explore the footwear needs and preferences of older adults in racket sports to inform footwear design and development. Semistructured interviews were conducted online with 16 participants (56-92 years of age) who typically play racket sports at least once per week. Thematic analysis was used to group basic themes into organizing themes. The organizing themes were comfort (general comfort, pain-free, and cushioning), functionality (relating to the structure of the shoe and performance), and choice (mostly around the appearance of the shoe). Comfort was a key priority for the majority of participants, although it was often stressed that the footwear must also be supportive. Support was frequently defined in relation to preventing ankle sprains; however, when asked directly about managing injury risk, avoiding certain shots and appropriate grip were mentioned over support. More than half of participants reported needing a wide-fitting sport shoe, which limited the footwear selection available to them. This study provides novel insight into the footwear requirements of active older adults, which can inform the development of footwear to facilitate safe and pain-free participation in sport for all.

The Influence of the Relative Timing between Pole and Heel Strike on Lower Limb Loading among Young and Older Naïve Pole Walkers.

Current research is unclear with respect to whether pole walking (PW) reduces lower limb loading when compared to regular walking (RW). Contradictory findings in the literature may be related to the relative timing between pole and foot contact events, which were examined in the current study among naïve pole walkers. Fourteen young (4 F; 25.3 ± 5.4 years) and 8 older adults (4 F; 68.5 ± 3.2 years) performed PW and RW trials along a force plate embedded walkway at two different visits. The time difference between pole and foot contact during both the onset of ground contact and the peak force application was calculated. Several kinetic measures were calculated for the lower limbs and poles. A significant decrease during PW, compared to RW, was found for foot impulse (2.1%; p < 0.01), peak vertical ground reaction force (vGRF) (3.4%; p < 0.01), rate of loading (5.2%; p=0.02), and peak push-off vGRF (2.1%; p=0.01). No difference in pole loading was found between age groups and visits. No significant correlations were found between the relative timing and foot loading measures. Significant low-to-moderate negative correlations were found between peak foot and pole vGRFs (p=0.04), peak foot vGRF and pole strike impulse (p=0.01), peak foot vGRF and pole impulse (p=0.02), and peak foot push-off vGRF and pole impulse (p=0.01), suggesting that as pole loading increased, foot loading decreased. Findings suggest timing between pole and heel contact may not be related to unloading the lower limbs but may be related to other aspects of pole use since PW reduced lower limb loading.

Effects of wearable resistance load placement on neuromuscular activity and stride kinematics: A preliminary study.

Wearable resistance (WR) training is a modality that allows athletes to perform loaded sport-specific movements to develop force and power outputs. The acute responses by which WR works is still relatively unknown, and the effects of WR load and location of the load has not yet been examined. To investigate the acute neuromuscular and stride characteristic responses to different wearable resistance (WR) loads and placements on the calf muscles during high-speed running. Ten well-trained subjects completed a workout of ten sets of three 10s runs at 18km.h-1 (20s of rest between runs and one min between sets). Five conditions were tested: (1) unloaded control, (2) bilateral 0.75 vs. 1.5% body mass (BM) loading on the distal posterior calf, (3) bilateral proximal vs. distal loading of 1.5% BM positioned posteriorly, (4) bilateral anterior vs. posterior loading of 1.5% BM positioned distally, (5) unilateral loading of 1.5% BM on the distal posterior calf. Data were collected using Electromyography (EMG) and back-mounted GPS-embedded accelerometers. Magnitude of differences of within athlete and between muscle comparisons were calculated using effect sizes (ES) ± 90% confidence limits (CL). No substantial differences in accelerometry data were observed between any of the loaded conditions and the control. EMG activity was lower for proximal loading compared to the control for the gluteus maximus (ES±90%CL; -0.72±0.41), vastus lateralis (-0.89±0.47) and vastus medialis (VM) (-0.97±0.46). Anterior loading induced substantially lower EMG activity for the semitendinosus (-0.70±0.48) and VM (-0.64±0.39) muscles compared with the control. EMG activity of the VM (-0.73±0.46) muscle was also substantially lower for posterior loading compared to the control. Unilateral loading induced no substantial differences in EMG activity between the loaded and unloaded legs. This preliminary study has provided a rationale for the performance of further investigations into the effects of WR lower limb loading on stride characteristics and EMG activity from a chronic standpoint using a larger population.

Differences in paretic lower limb loading and fluidity in sit-to-walk according to selection of the leading limb in individuals with stroke

BackgroundSit-to-walk is an asymmetric task that is challenging for individuals with stroke, and paretic limb loading at seat-off and movement fluidity may change according to whether the non-paretic or paretic leg is used as the leading limb. This study aimed to investigate differences in paretic limb loading and fluidity depending on whether the non-paretic limb or paretic limb was used as the leading limb. MethodsThirty-eight individuals with stroke performed sit-to-walk with each leg as the leading limb, and their movements were measured using a 3D motion analysis system. The paired t-test or Wilcoxon signed-rank test was used to assess differences according to limb selection in paretic limb loading ratio at seat-off and fluidity (Fluidity Index: ratio of the lowest to peak forward velocity before first initial contact). FindingsTwenty-two of 38 participants preferred to use the paretic limb as the leading limb. When leading with the paretic limb, the paretic limb loading ratio was significantly larger (p = 0.002), and the Fluidity Index was lower (p = 0.007). InterpretationSit-to-walk with the paretic leading limb seems to be an adaptive movement because many participants preferred leading with the paretic limb. However, selection of the leading limb in sit-to-walk involves a biomechanical tradeoff between paretic limb loading at seat-off and movement fluidity in individuals with stroke. Use of the paretic leading limb requires loading capacity of this limb, and the non-paretic leading limb must have high balance ability to merge sit-to-stand and gait initiation.

The angle of trunk rotation and symmetry of a lower limb loading in musicians of a symphony orchestra in Poland: a pilot study concerning instrument-specific results.

The study aimed to evaluate the angle of trunk rotation (ATR) and symmetry of lower limb loading in professional musicians. A total of 60 instrumentalists were examined: cellists, violinists and musicians playing wind instruments. The scoliometer examination was used to assess trunk asymmetry. The angle of trunk rotation was measured at segment: Th1-Th4, Th5-Th12, and Th12-L4. The maximum value (ATR max) and the sum of three rotations (STR) were calculated. Two scales were used to assess the symmetry of lower limb loading. Loading symmetry index (LSI) of the lower limb was calculated. Violinists have the highest mean values of ATR, ATR max, STR and LSI and musicians playing wind instruments have the lowest mean values. In the group of violinists and musicians playing wind instruments, a positive correlation was found between playing experience and ATR Th1-Th4. The body position during playing violin and cello may increase the angle of trunk rotation and the lower limb loading's asymmetry. Med Pr. 2022;73(2):85-93.

Multiday load carriage decreases ability to mitigate ground reaction force through reduction of ankle torque production

The aim of this study was to examine the impact of backpack load carriage on lower limb strength and loading rate change in a cohort that match military recruit profiles. Twenty-six participants walked on a treadmill either carrying a military load carriage system (32 kg) or unloaded for 2 h on two consecutive days. Participants ground reaction forces and strength measures were assessed using a force platform and dynamometry, respectively. Testing included assessments before and after treadmill walking on days one and two, and 24 h following day 2. When assessed by mixed methods ANOVA (alpha: 0.05) statistically significant interaction effects were observed for loading peak (p = 0.031), loading rate (p = 0.035) and plantarflexor torque dynamometry variables at 60°s−1 (p = 0.011) and 120°s−1 (p = 0.024). Repeated measures correlation highlighted associations between plantarflexor torque at 60°s−1 and loading rate (r = −0.901, p < 0.001). Load carriage reduced lower limb torque which did not recover between days. Plantarflexor torque reductions were associated with increases in loading rate. Practitioners should consider that load bearers are more likely to experience lower limb injury during multi-day load carriage. Future work should develop protocols to reduce plantarflexor torque loss in order to reduce ground reaction force change.

Varying alignment affects lower extremity joint and limb loading during yoga's triangle (Trikonasana) pose

BackgroundLimited biomechanical data exist describing how yoga asanas (postures) load the limbs and joints, and little evidence-based recommendations for yoga injury prevention are available. This study aimed to establish joint loading metrics for an injury-prone, yet common yoga pose, the Triangle asana (Trikonasana) by identifying how stance width adjustments alter lower extremity loading. MethodsEighteen yoga practitioners underwent 3D motion analysis while performing Trikonasana with self-selected (SS) stance width and −30, −20, −10, +10, +20, and +30% of SS stance width. Ground reaction forces (GRFs), joint forces, and joint moments were calculated for the leading and trailing limb ankle, knee, and hip. One-way repeated-measures analysis of variance determined differences in loading due to stance width. ResultsGRFs, net joint forces, and net joint moments were significantly affected by stance width where increasing stance width increased leading limb loading but decreased trailing limb loading. ConclusionsAltering stance width of Trikonasana influences lower extremity limb loading, and these loading responses were limb-dependent. Yoga practitioners and instructors can use this information to objectively support increasing or decreasing stance width to reduce or increase limb loading according to their goals or to make accommodations to groups such as beginners or at-risk populations for safer, more accessible yoga practices. Cuing a wider or narrower stance width will not have the same effect on both limbs.

The influence of a two-point contralateral crutch gait on the loading of the lower limb using a forearm crutch

Objectives: This biomechanical study was conducted to validate the assumption that using an elbow crutch on one side diminishes the loading of the contralateral lower limb. Methods: This study included in total 49 subjects: 39 patients and 10 healthy volunteers with a total of 114 observations divided in two groups. Group I, control group, (forearm crutch) contained 24 subjects (5 healthy volunteers and 19 Orthopedic patients). Group II (electronic forearm crutch) was made up of 25 subjects (5 healthy volunteers and 20 Orthopedic patients) with 60 observations. The electronic crutch recorded the speed of the crutch movement in the sagittal plane, the axial force exerted on the shaft of the crutch and the position of the crutch in the frontal plane in relation to the central axis of the subject. Results: holding the forearm crutch contralateral of the examined limb, we documented a 74% lower amount of limb loading. Holding the elbow crutch on the same side as the examined limb, we reported in 53.6% less loading. Conclusions: These results do not corroborate with the theoretical mechanical analysis of limb loading, where a diminishing load of the limb is predicted contralateral to an elbow crutch.

Early Superimposed NMES Training is Effective to Improve Strength and Function Following ACL Reconstruction with Hamstring Graft regardless of Tendon Regeneration.

The study aimed at investigating the effects of neuromuscular electrical stimulation superimposed on functional exercises (NMES+) early after anterior cruciate ligament reconstruction (ACLr) with hamstring graft, on muscle strength, knee function, and morphology of thigh muscles and harvested tendons. Thirty-four participants were randomly allocated to either NMES+ group, who received standard rehabilitation with additional NMES of knee flexor and extensor muscles, superimposed on functional movements, or to a control group, who received no additional training (NAT) to traditional rehabilitation. Participants were assessed 15 (T1), 30 (T2), 60 (T3), 90 (T4) and at a mean of 380 days (T5) after ACLr. Knee strength of flexors and extensors was measured at T3, T4 and T5. Lower limb loading asymmetry was measured during a sit-to-stand-to-sit movement at T1, T2, T3, T4 and T5, and a countermovement-jump at T4 and T5. An MRI was performed at T5 to assess morphology of thigh muscles and regeneration of the harvested tendons. NMES+ showed higher muscle strength for the hamstrings (T4, T5) and the quadriceps (T3, T4, T5), higher loading symmetry during stand-to-sit (T2, T3, T4, T5), sit-to-stand (T3, T4) and countermovement-jump (T5) than NAT. No differences were found between-groups for morphology of muscles and tendons, nor in regeneration of harvested tendons. NMES+ early after ACLr with hamstring graft improves muscle strength and knee function in the short- and long-term after surgery, regardless of tendon regeneration.

Association of Ankle Dorsiflexion and Landing Forces in Jumping Athletes.

Dorsiflexion range of motion restriction has been associated with patellar tendinopathy, but the mechanisms of how dorsiflexion restriction could contribute to knee overload remain unknown. Peak ankle dorsiflexion and ankle dorsiflexion excursion are negatively associated with peak vertical ground-reaction force (vGRF) and loading rate, and with peak patellar tendon force and loading rate, and positively associated with peak ankle plantar flexor moment. Cross-sectional study. Level 4. Kinematic and kinetic data of 26 healthy recreational jumping athletes were measured during a single-leg drop vertical jump. Pearson's correlation coefficients were calculated to establish the association between peak ankle dorsiflexion and ankle dorsiflexion excursion with peak vGRF and vGRF loading rate, with peak patellar tendon force and patellar tendon force loading rate, and with peak ankle plantar flexor moment. Ankle dorsiflexion excursion negatively correlated with peak vGRF loading rate (r = -0.49; P = 0.011) and positively correlated with peak ankle flexor plantar moment (r = 0.52; P = 0.006). In addition, there was a positive correlation between peak ankle dorsiflexion and peak vGRF (r = 0.39; P = 0.05). Ankle kinematics are associated with vGRF loading rate, ankle flexor plantar moment and peak vGRF influencing knee loads, but no association was observed between ankle kinematics and patellar tendon loads. These results suggest that increasing ankle dorsiflexion excursion may be an important strategy to reduce lower limb loads during landings but should not be viewed as the main factor for reducing patellar tendon force.

Calcaneal ultrasound attenuation as a predictor of bone density: Does the region of interest or loading influence the repeatability of measurement?

Introduction: It is well documented that sporting activities are important to increase bone mass. Depending on the quality and type of sport the amount of bone increment will vary. The attenuation of ultrasound as it passes through the calcaneal bone provides quantitative information about the density and structural properties of bone and is a clinically useful predictor of osteoporotic fracture risk in adults. Current ultrasound systems, however, assess different regions of interest (ROI) of the calcaneus, yield different attenuation values, involve different levels of lower limb loading and are likely prone to different levels of error. This study evaluated the repeatability of measures of ultrasound attenuation at three calcaneal ROI under varying levels of load. Methods: A custom-built transmission-mode ultrasound system was used to measure ultrasound attenuation in the calcaneus of 20 healthy participants (mean (±SD) age, 41.8 ± 19.6 years; height, 1.70 ± 0.17 m; and weight, 71.3 ± 23.3 kg). Repeated measurements were performed at three ROI (BW, JA, FG) and under four loading conditions (non-weightbearing, semi-weightbearing, bipedal stance, unipedal stance). Agreement between measures was evaluated using the Standard Error of Measurement (SEM) and limits of agreement (LA). Potential differences in attenuation between ROI, loading and measurement occasions were assessed using repeated measure analysis of variance ( 0.05). Results: Ultrasound attenuation ranged from 58.0±32.0 to 77.2 ± 27.6 dB/MHz across all conditions. There was a statistically significant difference between all ROI (F = 11.7, P = <0.001), which was moderated by loading (F = 2.4, P = 0.03).The narrowest LA for repeated measures of attenuation ranged between 25.7 dB/MHz and 11.6 dB/MHz across all sites. The SEM for attenuation was approximately 10 dB/MHz for both the FG and JA ROI during non-weightbearing and tended to reduce to approximately 5 dB/MHz with full weightbearing. Discussion: ROI and calcaneal loading are important considerations for measures of ultrasound attenuation at the calcaneus. Although measures of ultrasound attenuation are dependent on the ROI, lower limb loading tended to lower attenuation and improve the repeatability of measurements across sites. Given that the LA were 1.7 times smaller during unipedal stance than in non-weightbearing, calcaneal loading may be a useful method to improve the minimal detectable difference of the measurement. Conflict of interest statement: The authors declare no conflicts of interest.

Methods to determine saddle height in cycling and implications of changes in saddle height in performance and injury risk: A systematic review

ABSTRACT The objective of this systematic review was to assess the methods to determine bicycle saddle height and the effects of saddle height on cycling performance and injury risk outcomes. The key motivator of this review was to update and expand the finding reported by a previous narrative review published in 2011. The literature search included all documents from the following databases: Medline, Scopus, CINAHL, OVID and Google Scholar. Studies were screened against the Appraisal tool for Cross-sectional Studies to assess methodological quality and risk of bias. After screening the initial 29,398 articles identified, full-text screening was performed on 66 studies with 41 of these included in the systematic review. Strong evidence suggests that saddle height should be configured using dynamic measurements of the knee angle, and limb kinematics is influenced by changes in saddle height. However, moderate evidence suggests that changes in saddle height less than 4% of the leg length results in trivial to small changes in lower limb loads, and no effect on oxygen uptake and efficiency. It is also possible to state that there is limited evidence on the effects from changes in saddle height on supramaximal cycling performance or injury risk.

The ACL can hypertrophy in response to mechanical loading: an MRI study in elite athletes (157)

The ACL can hypertrophy in response to mechanical loading: an MRI study in elite athletes (157)

Early Pain Catastrophizing Exacerbates Impaired Limb Loading and 6-Minute Walk Test Distance 12Months After Lower Extremity Fracture.

Disability is common after lower extremity fracture (LEF). Although psychosocial factors have been associated with patient-reported outcomes after LEF, they have not been associated with objective measures of function. Aberrant gait patterns are important markers of function, but are poorly defined after LEF. The primary purpose of this study was to explore whether pain catastrophizing and fear of movement 6weeks after surgery were associated with injured limb loading outcomes and 6-minute walk test (6MWT) distance 12months after femur or tibia fracture. The secondary purpose was to determine if limb loading characteristics differed between injured and uninjured limbs. At 6weeks after LEF, patients completed validated measures of pain catastrophizing, fear of movement, and depression. At 12months, patients completed a 6MWT while wearing instrumented insoles that recorded the limb loading outcomes of stance time, impulse, and loading rate. Bivariate correlations assessed how patient and psychosocial characteristics at 6weeks were associated with injured limb loading outcomes and 6MWT distance. Multivariable regression analyses were performed to determine if psychosocial variables were associated with each outcome after controlling for depression and patient demographic and clinical characteristics. Finally, paired t tests compared limb loading outcomes between limbs. Forty-seven participants completed the 6MWT at 12months (65%), and 38 completed the 6MWT with the instrumented insoles. Fear of movement carried a poor relationship (r = 0.11-0.32) and pain catastrophizing a moderate relationship (r = 0.46-0.54) with 12-month outcomes. The regression results indicated that pain catastrophizing continued to be associated with all outcomes. Finally, the injured limb had significantly lower limb loading outcomes than the uninjured limb at 12months (Cohen d = 0.54-0.69). Pain catastrophizing early after LEF was associated with impaired limb loading and 6MWT distance at 12months. Impaired limb loading persists 12months after LEF. Further research is needed to determine whether rehabilitative efforts focused on pain catastrophizing can restore limb loading after LEF.

Effects of real-time feedback during decline walking on kinematic and kinetic gait parameters in a healthy population: study protocol for a randomized trial\xa0\u2014\xa0up and down

BackgroundThe control of the dynamic functional leg alignment (dFLA) and biomechanical load are important joint-related aspects regarding the development of osteoarthritis (OA). Research on level walking with feedback on load-related parameters has provided innovative treatment possibilities. With regard to walking on sloped surfaces, fundamental biomechanical knowledge exists. However, comprehensive data on the agreement of kinematics and kinetics of self-paced ramp versus sloped treadmill walking is lacking. Further, deeper insights into the control of the dFLA during decline walking and the usefulness of real-time feedback are missing.Methods/designThirty healthy participants aged between 18 and 35 years will be included. They will complete a three-dimensional gait analysis walking self-paced up and down on a 5-m ramp with a 10° inclination. Subsequently, speed-matched to ramp-up walking and self-paced 10° incline split-belt treadmill walking will be assessed. Afterwards, the participants will be observed under four different conditions of 10° declined walking on the same treadmill (a) self-paced walking, (b) self-paced walking with an internal focus of attention, (c) self-paced walking with real-time feedback, and (d) condition c speed-matched walking. The primary outcome parameter will be the frontal knee range of motion (fKROM). Secondary outcomes include the ground reaction force loading rate, spatial-temporal parameters, as well as sagittal, frontal and transversal kinematics, and kinetics for the lower extremities.DiscussionThe findings aim at improving the understanding of the effects of real-time feedback on the control of the dFLA and lower limb loading. Following clinical practicable methods for effective feedback devices can be developed and evaluated. Additionally, the first dataset comparing kinematic and kinetic parameters for decline and incline ramp walking versus walking on an instrumented treadmill will be available for appropriate intervention planning.Trial registrationClinicalTrials.govNCT04763850. Prospectively registered on 21 February 2021.