下背痛生物力学研究进展

下背痛是常见的、给社会造成严重经济负担的肌肉骨骼疾病。从生物力学角度出发,浅析腰椎损伤常见原因,下背痛患者正常活动、妊娠下背痛、下背痛患者治疗中的生物力学。     

The relationships between hamstring flexibility,lumbar flexion,and low back pain in rowers

Abstract

In this study, we examined the relationships between low back pain, hamstring flexibility, and lumbar flexion in rowers. Twenty-six male university rowers participated. Hamstring flexibility was assessed using an adjusted straight leg raise technique, and lumbar flexion was assessed via a distraction of skin marks protocol while long sitting. A questionnaire ascertained rowing details and low back pain characteristics. Low back pain was highly prevalent. No association was observed between low back pain and hamstring flexibility, or between hamstring flexibility and lumbar flexion. Sufferers of low back pain showed reduced lumbar flexion (P=0.03; 95% confidence interval = ? 3.7 to ?0.2). Results obtained using the adjusted straight leg raise technique suggested that low back pain was not associated with hamstring inflexibility, which suggests that increasing hamstring flexibility for rehabilitation or prevention of low back pain in rowers might not be necessary.     

Foot force production and asymmetries in elite rowers

The rowing stroke is a leg-driven action, in which forces developed by the lower limbs provide a large proportion of power delivered to the oars. In terms of both performance and injury, it is important to initiate each stroke with powerful and symmetrical loading of the foot stretchers. The aims of this study were to assess the reliability of foot force measured by footplates developed for the Concept2 indoor ergometer and to examine the magnitude and symmetry of bilateral foot forces in different groups of rowers. Five heavyweight female scullers, six heavyweight female sweep rowers, and six lightweight male (LWM) rowers performed an incremental step test on the Concept2 ergometer. Vertical, horizontal, and resultant forces were recorded bilaterally, and asymmetries were quantified using the absolute symmetry index. Foot force was measured with high consistency (coefficient of multiple determination>0.976 ± 0.010). Relative resultant, vertical, and horizontal forces were largest in LWM rowers, whilst average foot forces significantly increased across stroke rates for all three groups of rowers. Asymmetries ranged from 5.3% for average resultant force to 28.9% for timing of peak vertical force. Asymmetries were not sensitive to stroke rate or rowing group, however, large inter-subject variability in asymmetries was evident.     

Lumbopelvic motor control and low back pain in elite soccer players: a cross-sectional study

This study aimed to investigate the relationship between the history of low back pain and quality of lumbopelvic motor control in soccer players. Forty-three male elite soccer players (mean age, 18.2 ± 1.4 years) filled in questionnaires related to low back pain and attended a session to assess lumbopelvic motor control by means of five tests (the bent knee fall out test, the knee lift abdominal test, the sitting knee extension test, the waiter’s bow and the transversus abdominis test). A physiotherapist, blinded to the medical history of the participants, scored (0 = failed, 1 = correct) the performance of the players for each of the tests resulting in a lumbopelvic motor control score ranging from 0 to 5. Forty-seven per cent of the soccer players reported a disabling low back pain episode lasting at least two consecutive days in the previous year. These players scored worse lumbopelvic motor control than players without a history of low back pain (lumbopelvic motor control score of 1.8 vs. 3.3, P < 0.01). The between-groups difference was particularly marked for the bent knee fall out test, the knee lift abdominal test and the transversus abdominis test (P < 0.01). In conclusion, most soccer players with a history of low back pain had an altered lumbopelvic motor control. Further research should examine whether lumbopelvic motor control is etiologically involved in low back pain episodes in soccer players.     

Elite status maintained: a 12-year physiological and performance follow-up of two Olympic champion rowers

This case study reports the results of a 12-year (2005–2016) follow-up study of two Olympic champion rowers. The rowers were prospective athletes at the junior level when the study began, and we monitored their relevant physiological and performance data annually. Our findings indicated that their V?O_2max gradually increased up to about 22 years of age and leveled off at a value of approximately 7 l·min^?1 with minimal fluctuations thereafter. However, the variables that directly influence the V?O_2max changed. There was an age-related decline in maximal heart rate of about 0.5 beats·year^?1, while oxygen pulse, which serves as an indirect measure of stroke volume, correspondingly increased by about 1 ml O₂·beat^?1 per year, allowing the athletes to maintain exceptional V?O_2max values. Maximal minute power of the studied rowers, derived each year from their ramp-wise tests, closely resembled the mean power output sustained during the 2000-m all-out tests on a rowing ergometer. A 12-year improvement of 28% and 33% occurred for the mean power output sustained over 2000 and 6000-m on a rowing ergometer, respectively. The findings contribute to the body of knowledge on athletes representing the true elites of their respective sports.     

Do the peak and mean force methods of assessing vertical jump force asymmetry agree?

Abstract

The aim of this study was to assess agreement between peak and mean force methods of quantifying force asymmetry during the countermovement jump (CMJ). Forty-five men performed four CMJ with each foot on one of two force plates recording at 1,000 Hz. Peak and mean were obtained from both sides during the braking and propulsion phases. The dominant side was obtained for the braking and propulsion phase as the side with the largest peak or mean force and agreement was assessed using percentage agreement and the kappa coefficient. Braking phase peak and mean force methods demonstrated a percentage agreement of 84% and a kappa value of 0.67 (95% confidence limits: 0.45–0.90), indicating substantial agreement. Propulsion phase peak and mean force methods demonstrated a percentage agreement of 87% and a kappa value of 0.72 (95% confidence limits: 0.51–0.93), indicating substantial agreement. While agreement was substantial, side-to-side differences were not reflected equally when peak and mean force methods of assessing CMJ asymmetry were used. These methods should not be used interchangeably, but rather a combined approach should be used where practitioners consider both peak and mean force to obtain the fullest picture of athlete asymmetry.     

Reliability and discriminative ability of a modified Wingate rowing test in 12- to 18-year-old rowers

Abstract

We evaluated (1) the test–retest reliability of the Wingate test conducted on a rowing ergometer, and (2) the sensitivity of this test in determining the differences in performance attained by 12- to 18-year-old rowers. Altogether, 297 male rowers aged 12.0–18.9 years (mean ± s: 14.8 ± 1.7) completed a maximal 30-s test on a rowing ergometer, and 80 rowers representing all age groups were retested after 5–7 days. No change was evident in participants' performance in terms of mean power output (P = 0.726; Cohen's d = 0.04), maximal power output (P = 0.567; Cohen's d = 0.06), and minimum power output (P = 0.318; Cohen's d = 0.11) in the second test. The intra-class correlation coefficients were high (≥0.973) and coefficients of variation were low (≤7.3%). A series of analyses of variance were used to compare the performances among 12- to 18-year-old rowers, and age-related increases in performance were evident (P < 0.001; Cohen's d = 1.91–1.96). The age-related increases in performance were similar, although reduced, when the effects of body mass were partitioned out when using analysis of covariance (P < 0.001; Cohen's d = 0.82–0.85). The results suggest that: (1) the described test is reliable and can be used for maximal-intensity exercise assessment in youth rowing, and (2) it discriminates performance among 12- to-18-year-old rowers.     

瑜伽运动对女性慢性下背痛康复效果的分析

目的:探讨瑜伽运动对慢性下背痛患者的康复效果。方法:30例确诊慢性下背痛女性患者随机分为常规康复组(n=15)及瑜伽运动组(n=15),随后分别进行12周的常规康复及瑜伽运动,并对受试对象康复前、康复后12周末进行RDQ问卷评分、VAS疼痛强度评分及腰背功能的测定、评价。结果:12周后的瑜伽运动组患者的疼痛及压痛测定、腰背功能测定计分明显降低。结论:瑜伽运动对慢性下背痛患者慢性腰背疼痛、功能障碍有明显的康复效果。     

Total kinetic energy production of body segments is different between racing and training paces in elite Olympic rowers

Total kinetic energy (TKE) was calculated for 28 Canadian national team Olympic rowers during training on water, comparing low-stroke rates (18–22 stroke/min) and high-stroke rates (32–40 stroke/min), using video analysis. Stroke duration was normalized to 100%, beginning and ending at the “catches”, with the drive phase occurring first and recovery second. Two discrete points were identified during the stroke, both occurring when the fingers had the same horizontal position as the ankles (i.e. mid-drive and mid-recovery). The ratios of recovery-to-drive TKE at these points for the entire body at low and high-stroke rates were 0.36 ± 0.34 and 1.26 ± 0.54 respectively. Significant differences were found for the lower leg, upper arm and forearm segments, and within the female groups. Low-stroke rate is a typical training pace and high-stroke rate is analogous to a race pace. This study demonstrates that TKE production during recovery in a race was not replicated during training. While training at low-stroke rates is vital for technique refinement, this study stresses the importance of training appropriately for the energy expenditure during high-stroke rate recovery. This is commonly overlooked by coaches and athletes.     

Hatha瑜伽对非特异性下腰痛康复的影响

目的:探讨Hatha瑜伽对非特异性下腰痛患者康复的影响.方法:将60例NLBP患者随机均分为实验组和对照组.实验组采用Hatha瑜伽康复治疗,对照组采用走罐康复治疗.以Roland-Morris功能障碍调查(RMDQ)、疼痛程度视觉模拟量尺(VAS)、腰背肌耐力、腰椎关节活动度为测评依据,对患者治疗前、治疗6周、停止治疗6个月后的测定指数进行测评.结果:1)治疗6周后,实验组和对照组Roland-Morris评分和VAS评分较治疗前均显著下降(P<0.01),实验组显著低于对照组(P<0.05);实验组腰背肌耐力和腰椎关节活动度较治疗前均显著上升(P<0.01),对照组耐力和活动度无明显差异(P>0.05).2)停止治疗6个月后,两组组内各项指标停治前后比较,实验组差异不显著(P>0.05),对照组VAS和RMDQ评分明显上升(P<0.05),肌耐力和关节活动度无明显变化(P>0.05).结论:Hatha瑜伽、走罐治疗均能不同程度的减缓NLBP患者的疼痛.Hatha瑜伽作用优于走罐治疗,在停治一段时间后,瑜伽更能维持疗效,抑制复发,效果优于走罐治疗.     

Inspiratory muscle training effects on oxygen saturation and performance in hypoxemic rowers: Effect of sex

ABSTRACT

Exercise-induced arterial hypoxemia (EIAH) has been consistently reported in elite endurance athletes. This study examined the effects of an inspiratory muscle training protocol (IMT) on resting pulmonary function, end-exercise arterial oxygen saturation and performance in hypoxemic rowers. Twenty male and sixteen female well-trained hypoxemic rowers were divided into four groups: IMT-male, control-male, IMT-female and control-female. The IMT groups, additionally to the regular training, performed IMT (30 min/day, 5 times/week, 6 weeks). Before and after training, groups underwent an incremental rowing test, a 2000-m time trial and a 5-min “all-out” race. IMT increased respiratory strength in the IMT-male (135 ± 31 vs. 180 ± 22 cmH₂O) and IMT-female (93 ± 19 vs. 142 ± 22 cmH₂O) (P < 0.05). The IMT-female group exhibited lower EIAH and improved rowing performance in the 2000-m time trial (487 ± 32 vs. 461 ± 34 sec) and in the 5-min “all-out” test (1,285 ± 28 vs. 1,310 ± 36m) (P < 0.05). IMT protocol improved performance in IMT-male only in the 5-min test (1,651 ± 31 vs. 1,746 ± 37m) (P < 0.05). IMT may be a useful tool for increasing respiratory strength and enhancing performance in hypoxemic rowers, especially for women.

Abbreviations: EIAH: Exercise-induced arterial hypoxemia; IMT: inspiratory muscle training protocol; PaO2: partial pressure of arterial oxygen; SaO2: arterial oxyhemoglobin saturation; VO2max: maximal oxygen consumption; [(A-a)DO2]: alveolar-to-arterial oxygen difference; VA/Q: ventilation-perfusion inequality/mismatching; PImax: maximal inspiratory pressure; BMI: body mass index; BSA: body surface area; FVC: vital capacity; FEV1: forced expiratory volume in 1 sec; VCin: vital capacity; MVV12: maximal voluntary ventilation in 12 sec     

Asymmetry in elite rowers: effect of ergometer design and stroke rate

Between limb movement asymmetries and foot force production asymmetries are thought to be detrimental for both rower's performance and risk of injury, particularly when rowing frequently on ergometers. Several ergometers with different designs can be used by rowers as part of their indoor training. Hence, this study aimed to compare asymmetries in lower limb joint kinematics and foot force production with respect to ergometer design and rowing intensity. A new symmetry index was proposed to assess these asymmetries in elite rowers during a test on three ergometers. Additionally, the asymmetry in lower limb length was assessed to investigate its relationship with kinematic and kinetic asymmetries. Parameters describing medium (5–10%) or high (>10%) asymmetries were compared between rowing ergometers and intensities. Results indicated medium asymmetries for the ankle joint angle and hip–knee joint accelerations and high asymmetries for the resultant force and the ankle joint acceleration associated with a low inter-stroke variability. Kinetic asymmetry was neither correlated to kinematic asymmetry nor with lower limb length asymmetry. The use of a mobile ergometer led to higher joint acceleration asymmetries. Further studies are necessary to investigate the relation between these findings and muscular adaptations that may increase the risk of lower-back injury.     

跳绳运动对预防和治疗大学生腰背疼痛的效果研究

目的:探讨跳绳运动对大学生腰背疼痛的治疗效果。方法:将60例患者随机分为A、B两组,A组为实验组,B组为对照组,A组进行跳绳运动的训练,B组进行正常的生活作息,实验时间为3个月。结果:实验组患者腰背疼痛有明显改善,对照组患者腰背疼痛无明显变化,A组B组比较具有显著差异性(p0.05)。结论:跳绳运动对大学生腰背疼痛的治疗具有显著效果。     

赛艇运动员腰痛机制进展

腰部损伤是国内外赛艇运动员最常见的损伤。赛艇运动员的腰痛是多因素促发导致的结果,因此对其机制的研究较有局限性。近几年对赛艇运动员腰痛机制的研究主要是流行病学及生物力学的分析,研究表明：赛艇运动过程中,运动员脊柱承受的较大应力会使其前屈后伸超过其生理的活动度,而且,较小程度地骨盆旋转以及腰-骨盆运动的不协调增加了腰椎损伤的几率;腰部损伤跟大量的测功仪训练、相关肌肉功能下降有较大的相关性。而且国外的一些研究初步说明,赛艇运动员的腰、腹、大腿等部肌肉用力明显不对称,可能也是引起腰部损伤的重要原因。     

腰痛羽毛球运动员的功能评估

研究目的：对腰痛羽毛球运动员的部分功能进行测试,观察其活动范围、肌肉力量、肌电活动以及相应对称性。为了解羽毛球运动员损伤机制发生提供科学依据。研究对象：6名腰痛羽毛球运动员（男运动员4名,女运动员2名）。研究方法：对研究对象分别进行日本矫正外科协会（JOA）评分量表、躯干旋转、胸椎旋转、髋关节内外旋活动度、躯干等速旋转力量、等长背伸活动的肌电活动测试,并观察两侧差异比的平均值。研究结果：（1）腰痛运动员的躯干旋转、胸椎旋转以及髋关节外旋活动度平均差异比为（31.98±21.53）%,（19.8±17.08）%,（13.81±4.43）%大于10%,仅髋关节内旋活动度平均差异比为（5.62±5.63）%小于10%。胸椎和髋关节旋转动度有减小的趋势;（2）等速躯干旋转两侧峰力矩和平均功率差异没有显著性意义,峰力矩平均差异比为（5.45±1.78）%小于10%,而平均功率平均差异比为（12.78±11.40）%大于10%;（3）在等长背伸活动中,竖脊肌肌电活动的平均两侧差异比为（14.18±9.84）%大于10%,而多裂肌肌电活动的平均两侧差异比（9.90±7.92）%接近10%;竖脊肌和多裂肌的中位频率斜率（Median Frequency slope,MFs）均出现下降的趋势,但两侧差异比为（4.68±3.17）%,（5.35±5.40）%小于10%。结论：（1）腰痛羽毛球运动员躯干旋转、胸椎旋转、髋关节外旋活动范围存在对称性问题,且胸椎旋转、髋关节旋转有减少趋势;（2）躯干等速旋转平均功率存在对称性问题;（3）等长背伸任务中,竖脊肌和多裂肌出现疲劳,肌电活动存在对称性问题。     

Muscle morphology of the vastus lateralis is strongly related to ergometer performance,sprint capacity and endurance capacity in Olympic rowers

Rowers need to combine high sprint and endurance capacities. Muscle morphology largely explains muscle power generating capacity, however, little is known on how muscle morphology relates to rowing performance measures. The aim was to determine how muscle morphology of the vastus lateralis relates to rowing ergometer performance, sprint and endurance capacity of Olympic rowers. Eighteen rowers (12♂, 6♀, who competed at 2016 Olympics) performed an incremental rowing test to obtain maximal oxygen consumption, reflecting endurance capacity. Sprint capacity was assessed by Wingate cycling peak power. M. vastus lateralis morphology (volume, physiological cross-sectional area, fascicle length and pennation angle) was derived from 3-dimensional ultrasound imaging. Thirteen rowers (7♂, 6♀) completed a 2000-m rowing ergometer time trial. Muscle volume largely explained variance in 2000-m rowing performance (R² = 0.85), maximal oxygen consumption (R² = 0.65), and Wingate peak power (R² = 0.82). When normalized for differences in body size, maximal oxygen consumption and Wingate peak power were negatively related in males (r = ?0.94). Fascicle length, not physiological cross-sectional area, attributed to normalized peak power. In conclusion, vastus lateralis volume largely explains variance in rowing ergometer performance, sprint and endurance capacity. For a high normalized sprint capacity, athletes may benefit from long fascicles rather than a large physiological cross-sectional area.     

Morphological changes of the lateral abdominal muscles in adolescent soccer players with low back pain: A prospective cohort study

BackgroundMost papers examining the lateral abdominal muscles (LAMs) and low back pain (LBP) are cross-sectional, with groups of participants being divided into a control and an LBP group. We hypothesized that morphological measurements of the LAMs in adolescent soccer players may predict future LBP incidence. The aim of this study was to examine the associations between the morphology of LAMs and LBP incidence rate among adolescent soccer players.MethodsNinety-seven adolescent male soccer players with no LBP at baseline were recruited into the prospective cohort study. The thickness of the LAMs was measured at baseline by ultrasound imaging in a supine rest position. Nine cases of LBP occurred during the follow-up 6-month observation.ResultsAn obliquus internus (OI) asymmetry was related to increasing LBP risk (odds ratio = 19.99; 95%CI: 2.4–167.9). Spearman correlation also showed a linear relationship between OI asymmetry value and duration of LBP (R = 0.75, p = 0.02). An OI side-to-side difference greater than 1.25 mm suggests possible LBP incidence in the 6-month observation among adolescent soccer players.ConclusionThe morphological changes of the OI may be related to LBP’s incidence in adolescent soccer players. The presence of OI asymmetry increases the odds of LBP by at least 2.4 times. Hypertrophy of the OI on one side of the body may contribute to trunk muscle imbalance.     

针对性核心训练对存在腿长差异的非特异性腰疼人群长期疗效研究

研究目的:探索针对性核心训练对存在腿长差异特征的非特异性腰疼人群的长期疗效。研究方法:筛查出48名存在腿长差异特征的非特异性腰疼人群,将其分为实验组(n=24)和对照组(n=24)。对照组采取核心训练,实验组采取针对改善长腿差异的核心训练。观察各组治疗前、治疗后及治疗结束一个月后时视态模拟评分法(Visual Analogue Scales,VAS)、日本骨科学会评分(Japanese Orthopaedic Association Scores,JOA)并观察疗效。实验结果:实验前,两组受试者VAS、JOA均无显著性差异(p> 0.05)。两组受试者实验前较实验后、实验后一个月VAS均降低(p <0.01),JOA均升高(p <0.01)。治疗结束一个月后,实验组VAS低于对照组(p <0.01)、实验组JOA高于对照组(p <0.05)。结论:针对改善腿长差异的核心训练对比单纯核心训练对于改善存在腿长差异的非特异性腰疼人群长期疗效、主观感受、疼痛程度、腰椎功能效果更优。     

Effects of load on ground reaction force and lower limb kinematics during concentric squats

The purpose of this study was to examine the effects of external load on vertical ground reaction force, and linear and angular kinematics, during squats. Eight males aged 22.1?±?0.8 years performed maximal concentric squats using loads ranging from 7 to 70% of one-repetition maximum on a force plate while linear barbell velocity and the angular kinematics of the hip, knee and ankle were recorded. Maximum, average and angle-specific values were recorded. The ground reaction force ranged from 1.67?±?0.20 to 3.21?±?0.29 times body weight and increased significantly as external load increased (P?<?0.05). Bar linear velocity ranged from 0.54?±?0.11 to 2.50?±?0.50?m?·?s^?1 and decreased significantly with increasing external load (P?<?0.05). Hip, knee and ankle angles at maximum ground reaction force were affected by external load (P?<?0.05). The force?–?barbell velocity curves were fitted using linear models with coefficients (r ²) ranging from 0.59 to 0.96. The results suggest that maximal force exertion during squat exercises is not achieved at the same position of the lower body as external load is increased. In contrast, joint velocity coordination does not change as load is increased. The force?–?velocity relationship was linear and independent from the set of data used for its determination.     

非特异性腰痛患者腰骶结构特征及其影响因素

研究非特异性腰痛（non-specific low back pain,NLBP）患者的腰骶结构特征及其影响因素。方法：招募筛选NLBP患者71例（NLBP组）及29例无腰痛的健康人群（Con组）。填写问卷评估疼痛程度和腰功能障碍,并分别拍摄矢状面及额状面的X光片,测定腰椎前凸程度和骨盆侧倾程度的相关指标。研究发现：①NLBP组腰椎前凸程度与Con组相比无显著性差异（P>0.05）;②NLBP组与Con组相比骨盆发生明显侧倾（P<0.05）;③性别对NLBP患者腰骶结构没有影响;④不同年龄的NLBP患者腰椎结构有发生不同的改变,青年患者与中老年患者相比,腰骶出现了显著的腰曲变直（P<0.05）及骨盆侧倾（P<0.01）;⑤症状也会影响NLBP患者的腰椎前凸程度（P<0.05）。研究结论：①骨盆侧倾是NLBP患者的共性,可将该指标用于临床诊断和疗效评估;②不同年龄、性别和症状的NLBP患者进行康复时应有针对性。