Evaluation of Gait Characteristics in Subjects With Locomotive Syndrome Using the Wearable Gait Sensors

Background: Locomotive syndrome (LS) is a condition where a person requires nursing care services due to problems with locomotive abilities and musculoskeletal systems. Individuals with LS have a reduced walking speed compared to those without LS. However, differences in lower-limb kinematics and during walking between individuals with and without LS are not fully understood. The purpose of this study is to clarify the characteristics of gait kinematics using wearable sensors for individuals with LS.Methods: We assessed 125 people aged 65 years and older who utilized a public health promotion facility. The participants were grouped into Non-LS, LS-stage 1, LS-stage 2 (large number indicate worse locomotive ability) based on 25-question Geriatric Locomotive Function Scale (GLFS-25). Spatiotemporal parameters and lower-limb kinematics during 10-m walking test were analyzed by 7-inertia-sensors based motion analysis system. Peak joint angles during stance and swing phase as well as gait speed, cadence and step length were compared among all groups.Results: The number of each LS stage was 69, 33, 23 for Non-LS, LS-stage 1, LS-stage 2, respectively. LS-stage2 group showed significantly smaller peak hip extension angle, hip flexion angle and knee flexion angle than Non-LS group (hip extension: Non-LS: 9.5 ± 5.3°, LS-stage 2: 4.2 ± 8.2°, P = 0.002; hip flexion: No-LS: 34.2 ± 8.8°, LS-stage 2: 28.5 ± 9.5°, P = 0.026; knee flexion: Non-LS: 65.2 ± 18.7°, LS-stage 2: 50.6 ± 18.5°, P = 0.005). LS-stage 1 and LS-stage 2 groups showed significantly slower gait speed than Non-LS group (Non-LS 1.3 ± 0.2 m/s, LS-stage1 1.2 ± 0.2 m/s, LS-stage2 1.1 ± 0.2 m/s, P < 0.001).Conclusions: LS-stage2 group showed significantly different lower-limb kinematics compared with Non-LS group including smaller hip extension, hip flexion and knee flexion. The intervention based on these kinematic characteristics measured by wearable sensors would be useful to improve the locomotive ability for individuals classified LS-stage2.

Reliability of the Hip Extension Lower Exercise as a Measure of Eccentric Hamstring Strength

Hamstring strain injury (HSI) is a very common lower-body injury in field sports, and eccentric (ECC) hamstring strength is a potential modifiable risk factor, therefore having reliable eccentric hamstring strength assessments is critical. The aim of this study was to access test–retest reliability of the hip extension lower (HEL) exercise as a measure of ECC hamstring strength and inter-limb asymmetries. Twelve male elite level soccer players (mean; age: 21.8 years; height: 180.4 cm; weight: 75.7 kg) volunteered to participate in this study. Participants were from the same soccer club, covered all playing positions, and had no current injury issues. Participants performed two familiarization sessions to acquaint themselves with the device and exercise protocol. During testing, each participant performed three repetitions with 60s intra-set recovery provided. Average and peak force (N) was recorded for both limbs. Testing sessions took place on the same day and time over a two-week pre-season period and followed a full recovery day. Intraclass Correlation Coefficient (ICC), Coefficient of Variation (CV%), Minimal Detectable Change (MDC) and Typical Error (TE) were used to assess reliability. The HEL showed excellent reliability for average force (N) in the left (ICC (95% CI) = 0.9 (0.7–0.97); TE = 14.1 N, CV% = 1.87; MDC = 39.06 N) and right (ICC (95% CI) = 0.91 (0.73–0.97); TE = 20.89 N, CV% = 3.26; MDC = 57.87 N) limb, and also excellent reliability for peak force in the left (ICC (95% CI) = 0.91 (0.71–0.97); TE = 13.55 N, CV% = 1.61; MDC = 57.87 N) and right (ICC (95% CI) = 0.9 (0.7–0.97); TE = 21.70 N, CV% = 3.31; MDC = 60.11 N) limb. This data suggests the HEL as a reliable measure of both ECC hamstring strength and inter-limb asymmetries. Practitioners should consider the HEL as a reliable choice for measuring and monitoring eccentric hamstring strength in their athletes.

Comparison of crossover and jab step start techniques in sprinting for football and handball players

There are two techniques for a lateral sprint start: crossover (CS) and jab step (JS) starts. This study aimed to elucidate the difference in the CS and JS starts in terms of sprint performance and leg kinetics in athletes from ball-and-goal type sports (e.g. soccer and handball). Nineteen male athletes performed CS and JS starts, during which their motion and the force they applied to the ground were simultaneously recorded using a motion-capture system and two force platforms. The results showed that, although 5-m time via video analysis did not differ between CS and JS starts, forward velocity of centre of gravity (CG) and normalised average horizontal external power were greater for the JS start than the CS start. From waveform analysis, greater positive joint power in the sagittal plane leading to greater positive work in the JS start were found in the first three quarters of the push-off phase for rear hip extension and in the subsequent push-off phase for rear ankle plantar flexion. In conclusion, the results suggest that the JS start is superior to the CS start for start quickness, though the gains in the start did not appear to transfer to the 5-m performance. Moreover, greater positive joint power in the first three quarters of the push-off phase for the rear hip extension and in the subsequent push-off phase for the rear ankle plantar flexion were considered to be important contributing factors to the better performance of the JS start.

Biomechanical Effects on Lower Extremities in Human-Robot Collaborative Agricultural Tasks

The present study pertains to a key aspect of human-robot collaborative systems which is usually underestimated, namely occupational health prolepsis. The aim of this investigation was to assess the biomechanical effects of manual symmetric load lifting related to a synergistic agricultural task that utilizes an unmanned ground vehicle to undertake the carriage of loads. Towards that goal, kinetic and kinematic data were collected from the lower extremities of thirteen experienced workers, by testing three different deposit heights (70, 80, 90 cm) corresponding to possible adjustments of the available agricultural robot. Moreover, the muscle activation levels of three lower extremity muscles and one trunk muscle were evaluated via a wireless electromyography system. Overall, the experimental findings revealed that the lower examined load height was associated with larger knee flexion moments and hip extension moments. Nevertheless, this height was related to lower activation mainly of the erectus spinae muscles. Finally, insignificant alterations were observed for the ankle joint as well as the activation levels of the other muscles. Consequently, a height equal to 90 cm is suggested, however, by avoiding extreme lumbar postures. The current results can be exploited for possible ergonomic interventions concerning the optimal deposit height of a robotic platform when a similar case is designed.

Is Dynamic Spino-Pelvic Alignment During Gait Associated with Quality of Life in Patients with Degenerative Lumbar Spinal Canal Stenosis?

This study aims to investigate the relationship between dynamic alignment of the spine and pelvis during gait and quality of life (QOL) in lumbar spinal canal stenosis (LSS) patients. We evaluated QOL using the Oswestry Disability Index (ODI), trunk and hip muscle strength as physical function, static spinal alignment, and dynamic spinal/pelvic alignment during gait. The relationship between the ODI score and physical function or static and dynamic alignment were examined. A total of 30 preoperative patients with LSS were participated in this study. ODI score significantly correlated with trunk extension strength (r = -0.559, p = 0.002), hip extension strength (r = -0.473, p = 0.011), maximum flexion angle of spine during gait (r = -0.551, p = 0.002) and maximum anterior tilt angle of pelvis (r = 0.528, p = 0.004). Multiple regression analysis showed that trunk extension strength (standardized β; - 0.35), maximum spinal flexion angle (standardized β; - 0.51) and hip extension strength (standardized β; - 0.40) significantly affected the ODI score, with adjusted coefficient of determination of 0.62. The results of this study showed that the LSS patients with weak hip or trunk extensor muscles, a greater angle of pelvic tilt or a less spinal flexion during gait had a lower QOL.

The Relationship between Leg Extension Angle at Late Stance and Knee Flexion Angle at Swing Phase during Gait in Community-Dwelling Older Adults

This study aimed to clarify the relationship between leg extension angle and knee flexion angle during gait in older adults. The subjects of this cross-sectional study were 588 community-dwelling older adults (74.6 ± 6.1 y). Segment angles and acceleration were measured using five inertial measurement units during comfortable gait, and bilateral knee and hip joint angles, and leg extension angle, reflecting whole lower limb extension at late stance, were calculated. Propulsion force was estimated using the increase in velocity calculated from anterior acceleration of the sacrum during late stance. Correlation analysis showed that leg extension angle was associated with knee flexion angle at swing phase and hip extension angle and increase in velocity at late stance (r = 0.444–508, p < 0.001). Multiple regression analysis showed that knee flexion angle at mid-swing was more affected by leg extension angle (β = 0.296, p < 0.001) than by gait speed (β = 0.219, p < 0.001) and maximum hip extension angle (β = −0.150, p < 0.001). These findings indicate that leg extension angle may be a meaningful parameter for improving gait function in older adults due to the association with knee kinematics during swing as well as propulsion force at late stance.

Hamstring Torque, Velocity and Power Elastic Band Measurements during Hip Extension and Knee Flexion

The quantitative dynamic monitoring of the performance of hamstring muscles during rehabilitation and training cannot currently be undertaken using elastic resistance bands. Hip extension with a fully extended knee involves hamstring agonists, while knee flexion involves only the hamstring. The purpose of this study is to provide normative values of torque, velocity and power involving hamstring muscles opposing elastic bands. Twenty amateur athletes aged 25.7 ± 4.9, were studied during two motor tasks—hip extension and knee flexion, both isometric & dynamic—with an elastic resistance band and DINABANG portable instrument. We compared the peak isometric torque in hip extension with agonists (2.93 Nm/kg) and without them (1.21 Nm/kg): the difference is significant. The peak angular limb velocity—starting at 50% of the maximum torque—is smaller in hip extension with agonists (215.96°/s) than in a knee flexion without them (452.56°/s). The combination of peak torque and peak velocity estimates power and there is no difference (p = 0.051) with and without agonists: 452.56°Nm/s.kg without agonists and 542.13°Nm/s.kg with them. This study opens the possibility of monitoring torque–velocity–power profiles for hamstring exercise in open chain.

Effect of Strength Training on Jump-Landing Biomechanics in Adolescent Females

Background: Sex-based differences in neuromuscular characteristics relevant to anterior cruciate ligament (ACL) injury risk may arise as compensation for divergent strength development during puberty. Strength training during this period may prevent the development of these undesirable neuromuscular characteristics. Hypothesis: Strength-trained middle school girls will have improved jump-landing biomechanics compared with control participants. Study Design: Cohort study. Level of Evidence: Level 3. Methods: Maximum voluntary isometric contraction in hip extension and abduction and knee extension and flexion as well as Landing Error Scoring System (LESS) scores were collected for healthy female middle school students of grades 6 to 8. Strength-training participants (STR: N = 30; height, 1.63 ± 0.07 m; mass, 48.1 ± 7.6 kg; age, 12.5 ± 1.0 y) were matched with control participants (CON: N = 30; height, 1.60 ± 0.09 m; mass, 47.2 ± 8.9 kg; age, 12.6 ± 0.9 y). The training consisted of a 6-month strength-training program administered through a gym class curriculum that targeted the lower extremity. A repeated-measures mixed-model analysis of variance was used for comparisons between groups and across time (α = 0.05). Stepwise linear regression was used to examine the relationship between strength change and LESS score change. Results: Strength values (N·m/kg) increased across time and to a greater degree in STR for hip extension (baseline 3.98 ± 1.15 vs follow-up 4.77 ± 1.80), hip abduction (4.22 ± 1.09 vs 5.13 ± 2.55), and knee flexion (3.27 ± 0.62 vs 3.64 ± 1.40) compared with CON. LESS grades significantly decreased across time in STR (5.58 ± 1.21 vs 4.86 ± 1.44) and were significantly lower than CON (5.98 ± 1.42) at follow-up ( P < 0.001). The change in hip extension and knee extension strength explained 67% of the variance ( P < 0.001) in the LESS change score in the STR group. Conclusion: A school-based strength-training program that focused on hip and knee musculature significantly improved jump-landing biomechanics (as determined by LESS) relevant to ACL injury risk. Further investigation using different strength-training approaches in this age group is warranted. Clinical Relevance: Strength training during adolescence holds promise as an injury prevention program. The use of a school-based approach is novel and may represent a robust opportunity for injury prevention programs, as physical education class is often mandatory in this age group.