A Controlled and Retrospective Study of 144 Chronic Low Back Pain Patients to Evaluate the Effectiveness of an Intensive Functional Restoration Program in France.

STUDY DESIGN: A controlled and retrospective study of 144 chronic low back pain patients to evaluate the effectiveness of an intensive functional restoration program in France. OBJECTIVE: Evaluating the efficiency of an intensive, dynamic and multidisciplinary functional restoration program in patients with chronic low back pain (LBP), during 6 and 12 months follow up. SUMMARY OF BACKGROUND DATA: Chronic low back pain disease has a multifactor nature, involving physical, psychological professional and social factors. A functional restoration program (FRP) has been included in a multidisciplinary training program which provides an efficient therapeutic solution. However, the effectiveness of an FRP has not been yet established. METHODS: 144 subjects (71 males, 73 females) with chronic low back pain were included in a functional restoration program. The FRP includes physiotherapy and occupational therapy interventions together with psychological counselling. Patients participated as in- or outpatients 6 h per day, 5 days a week over 5 weeks. Pain intensity, trunk flexibility, trunk strength, lifting ability, quality of life and return to work were recorded before, immediately after, and at 6 months and 12 months after the treatment period. RESULTS: All outcome measures were significantly higher just after the FRP (144 patients) and at 6 and 12 months (from available data in 31 subjects) compared to pre-treatment values. This FRP for chronic low back pain maintained its benefits whatever the patient's activities. CONCLUSIONS: The effects reflected on all outcome measures, both on short and long term follow-up. The multidisciplinary FRP for chronic low back pain patients durably stopped the de-conditioning syndrome and involved new life-style habits for the patient, daily pain management and a return to work.

Functional restoration of the spine: effect of initial pain level on the performance of subjects with chronic low back pain.

BACKGROUND: Chronic low back pain is a persistent lumbar pain of multifactorial origin. The initial pain level remains poorly used to analyze and compare responses in low back pain patients in a reconditioning program. OBJECTIVE: To assess and evaluate the responses of subjects with very painful chronic low back pain in a dynamic and intensive care program. METHODS: A total of 134 patients with chronic low back pain were included in a spine functional restoration program for five weeks. The subjects were classified into two groups by level of pain: a group experiencing severe pain (n=28) and a group experiencing mild to moderate pain (n=106). All subjects received identical support consisting primarily of physiotherapy, occupational therapy, cardiovascular and muscular reconditioning as well as psychological counselling. The physical parameters (flexibility, muscular strength) and psychological (quality of life) were measured before (T0) and after the program (T5sem). RESULTS: All physical and functional performances of the subjects with severe pain were lower and the impact of back pain on quality of life for these subjects was increased. All significant differences at T0 between the two groups were no longer present at T5sem. DISCUSSION: Muscular atrophy is more important in subjects with severe pain at T0. The intense pain would cause kinesiophobia and central inhibition in chronic low back pain. The analgesic effects of the spine functional restoration program allowed subjects to obtain similar physical, functional and psychological performances at the end of the five weeks of support. CONCLUSIONS: Patients with very painful chronic low back pain respond favourably to the dynamic and intensive program. The intensity of low back pain had no effect on responses to the program. The spine functional restoration program enables patients to better manage their pain, whatever its level.

The application of a classification-tree model for predicting low back pain prevalence among hospital staff.

Low back pain (LBP) is a widespread musculoskeletal condition that frequently occurs in the working-age population (including hospital staff). This study proposes a classification-tree model to predict LBP risk levels in Sacré-Cœur Hospital, Lebanon (as a case study-236 chosen staffs) using various predictor individual and occupational factors. The developed tree model explained 80% of variance in LBP risk levels using standing hours/day (90% in relative importance), job status/sitting hours per day (80% each), body mass index (71%), working days/week (63%), domestic activity hours/week (36%), weight (35%), job dissatisfaction/sitting on ergonomic chairs (30% each), height (28%), gender (27%), sufficient break time (26%), using handling techniques/age (25% each), job stress (24%), marital status/wearing orthopedic insoles/extra professional activity (22% each), practicing prevention measures (20%), children care hours/week (16%), and type of sport activity/sports hours per week, car sitting, and fear of changing work due to LBP (15% each). The overall accuracy of this predictive tree once compared with actual subjects was estimated to be 77%. The proposed tree model can be used by expert physicians in their decision-making for LBP diagnosis among hospital staff.

Examining self-training procedures in leisure swimming.

This study investigated contents of training sessions from 387 regular swimmers involved in a recreational workout without supervision. We did use multiple correspondences analysis in order to identify self-trained swimmers typology in a sample from a social networking website, focusing on swimming practice. Self-reported parameters (n = 12) were age, gender, practice frequency, supervision in physical activity experiment, main training target, main reason for swimming choice, swimming session duration and distance, most used swimming stroke and material, quality of the training control, and training evolution during a year. Results have highlighted different training strategies and targets according to gender and age. Male strategy consists in performing higher distance (1818.8 ± 644.5 m vs. 1453.0 ± 603.3, p < 0.05 for male and female respectively) by using several swim stroke and gears involving upper body muscles (front crawl, pull buoy and paddles). More concerned about duration of their sessions, women are mainly using breaststroke. Backstroke is associated with people aged higher than 50. We also have established a connection between motives according to ages and long term strategies. The main motivation for middle aged people appears to be general health benefits by performing identical swimming session without evolution during a year. People aged from 20 to 30 are divided between an identical swimming session strategy and an increase in distance or in intensity strategy during a year. This population appears to be concerned about a global health benefits and a body shape effects. Suggestions are made to improve swimming practice environment during free time sessions according to the main results. Key PointsMale strategy consists in performing higher distance by using several swim stroke and gears involving upper body muscles whereas women are more concerned about effort duration and use breaststroke in majority.The main motivation for middle aged people appears to be general health benefits whereas people aged from 20 to 30 appears to be concerned about a global health benefits and a body shape effects.Excepted middle age people, recreational swimmers have low control quality of their session even if they have a good skill level. This suggests to improve health strategy education and swimming pool environment.

On the quantitative relationships between individual/occupational risk factors and low back pain prevalence using nonparametric approaches.

OBJECTIVES: To explore dual quantitative relationships between low back pain (LBP) prevalence and different individual and occupational risk factors, and detect the most important ones which can be used as weighted input data in LBP prediction diagnosis models, providing effective tools to help with the implementation of protection and prevention strategies among hospital staff. METHODS: Fourteen predictor individual risk factors (e.g., age, gender, body mass index BMI [kg/m(2)], domestic activity, etc.) and 17 occupational risk factors (e.g., job status, standing hours/day, sufficient break time, job dissatisfaction, etc.) were collected using self-reported questionnaire among the staff of Sacré-Coeur hospital - Lebanon (used as a case study), and correlated with LBP prevalence using Kendall's tau-b bivariate nonparametric approaches. RESULTS: This study indicates that among the investigated occupational risk factors, job status, working hours/day, and standing hours/day are the most influencing on LBP prevalence (highly correlated with other factors at 1 and 5% confidence levels). It also shows that strong positive (between 0.25 and 0.65)/negative (from -0.38 to -0.26) statistical correlations to LBP prevalence exist between these risk occupational factors and working days/week, sitting hours/day, job stress, job dissatisfaction, children care, and car driving. The weekly hours of domestic activity, the staff height, and gender type have proven also to be the strongest individual factors in aggravating LBP disease. These individual factors are highly correlated at 1% significance level (ranging between 0.28 and 0.49 for positive correlations, and from -0.49 to -0.25 for negative ones) to children care, weight, extra professional activity, and use of handling techniques. CONCLUSIONS: These obtained bivariate correlations can be used successfully by expert physicians in their decision making for LBP diagnosis.

Effect of stroke rate reduction on swimming technique during paced exercise.

The purpose of this study is to analyze the acute adaptations of motor organization subsequent to a reduction in spontaneous stroke rate (SR) at different swimming speeds, a task constraint that is currently used by trainers to improve stroke technique. Ten well-trained swimmers (8 males and 2 females, whose mean swimming speed on a 400-m front crawl stroke represents 76.8 ± 3.7% and 73.3 ± 2.7% of the mean speed of the short-course pool world record, respectively) performed 3 sets of 3 time to exhaustion trials in front crawl at paces corresponding to 95%, 100%, and 110% of the mean speed measured in a 400-m race. During the first set, individual SR was continuously recorded and averaged. During the second set (Fixed), participants were constrained to swim at their individual corresponding SR. For the third set (Lowered), an individual corresponding SR value lowered by 5% was imposed. Durations of trials and arm stroke phases durations were analyzed. The results showed that the durations of the whole trials declined significantly from the Fixed set to the Lowered set (p < 0.05). Swimmers spent more time in the nonpropulsive phases (increases ranged from 8.6-13.2%; p < 0.05), and the duration of the propulsive phases did not differ significantly in the lowered set. The significant decline in exercise durations might have been caused by an unusual muscular solicitation. Swimming technique changes during trials in the Fixed set suggest an increase in magnitude and efficiency in the propulsive force and a better body streamlining to limit an increase of the resistive impulse in between arm propelling actions. In conclusion, these results should be taken into account to better define training-set technical benefits and better include the impact of such task constraints into the training schedule.

Effects of a 6-week plyometric training program on performances in pubescent swimmers.

This study examined in pubescent swimmers the effects on front crawl performances of a 6-week plyometric training (PT) in addition to the habitual swimming program. Swimmers were assigned to a control group (n = 11, age: 14.1 ± 0.2 years; G(CONT)) and a combined swimming and plyometric group (n = 12, age: 14.3 ± 0.2 years; GSP), both groups swimming 5.5 h · wk(-1) during a 6-week preseason training block. In the GSP, PT consisted of long, lateral high and depth jumps before swimming training 2 times per week. Pre and posttests were performed by jump tests (squat jump [SJ], countermovement jump [CMJ]) and swim tests: a gliding task, 400- and 50-m front crawl with a diving start (V400 and V50, m · s(-1)), and 2 tests with a water start without push-off on the wall (25 m in front crawl and 25 m only with kicks). Results showed improvement only for GSP for jump tests (Δ = 4.67 ± 3.49 cm; Δ = 3.24 ± 3.17 cm; for CMJ and SJ, respectively; p < 0.05) and front crawl tests (Δ = 0.04 ± 0.04 m · s(-1); Δ = 0.04 ± 0.05 m · s(-1); for V50 and V400, respectively; p < 0.05). Significant correlations were found for GSP between improvements in SJ and V50 (R = 0.73, p < 0.05). Results suggested a positive effect of PT on specific swimming tasks such as dive or turn but not in kicking propulsion. Because of the practical setup of the PT and the relevancy of successful starts and turns in swimming performances, it is strongly suggested to incorporate PT in pubescent swimmers' training and control it by jump performances.

Stroking characteristics during time to exhaustion tests.

PURPOSE: Race analyses during swimming reveal how exercise duration affects both clean swimming speed (v), stroke rate (SR), and stroke length (SL). The aim of this study is to provide an explanation for the change of SL and SR during paced exercise swimming the front crawl through an analysis of intracycle changes in motor organization. METHODS: Trained swimmers (N = 10) swam three times to exhaustion (TTE in seconds) at predetermined velocities corresponding to 95%, 100%, and 110% of the mean speed attained in a 400-m race (V 400). During TTE tests, SR, SL, durations of the glide + catch, pull, push, and recovery phases (s) were measured. Assessment of arm coordination was made through the calculation of the index of coordination (IdC). The time allotted to propulsion per distance unit was estimated (T prop). RESULTS: For all tested speeds, fatigue development induced a gradual increase of SR with concomitant decrease of SL. The duration of the nonpropulsive phases decreased, whereas the duration of the propulsive phases per stroke remained constant. The IdC increased reflecting a reduction of the lag time between two consecutive propulsive actions. Consequently, T prop increased. CONCLUSION: Fatigue development induced an increase of the SR to compensate for the reduced capacity to generate a propulsive impulse per stroke. The change in arm coordination allows a better chain of the propulsive actions and leads to a greater time allotted to propulsion per distance unit. Such motor adaptation ensures that the overall propulsive impulse remained constant whereas average propulsive force per arm stroke is reduced.

Changes in swimming technique during time to exhaustion at freely chosen and controlled stroke rates.

The aim of this study was to assess technical changes during constrained swimming in time-to-exhaustion tests. Ten swimmers of national standard performed a maximal 400-m front crawl and two sets of exhaustion tests at 95%, 100%, and 110% of mean 400-m speed. In the first set (free), swimmers had to maintain their speeds until exhaustion and mean stroke rate was recorded for each test. In the second set (controlled), the same speed and individual corresponding stroke rate were imposed. The durations of the exhaustion tests, relative durations of the stroke phases, and arm coordination were analysed. For each speed in the "controlled" set, the exhaustion tests were shorter. Moreover, variables were consistent, suggesting a stabilization of stroke technique. Under the free condition, stroke rate increased to compensate for the decrease in stroke length. At the same time, swimmers reduced the relative duration of their non-propulsive phases in favour of the propulsive phases. Thus, swimmers changed their arm coordination, which came close to an opposition mode. These two constraints enable swimmers both to maintain their stroking characteristics and develop compensatory mechanisms to maintain speed. Moreover, stroke rate can be seen as a useful tool for controlling arm technique during paced exercise.

Variations of stroking parameters associated with 200 m competitive performance improvement in top-standard front crawl swimmers.

The aim of this study was to analyse the variations of stroking parameters (speed, stroke length, stroke rate, and stroke index) associated with the 200 m front crawl competitive performance improvement. Two races completed by 17 top swimmers were analysed in the 200 m freestyle final of French or European championships, each final being separated by two years. All the swimmers' performances were bettered in the second race (mean +/- SD: 113.44 +/- 2.50 vs 111.78 +/- 2.71 s; p < 0.01) and were associated with a significant increase of stroke rate without variation of average stroke length and stroke index values (p > 0.05). Swimmers emphasized the first part of the race, with higher speed in the first three lengths, higher stroke rate in the first two lengths and lower stroke length in the first one. Stroke length and stroke rate variations were highly correlated (r = 0.98; p < 0.05). In 11 of the 17 swimmers, the improvement was concomitant with a decrease in stroke length and an increase in stroke rate. Only one swimmer's improvement was associated with a substantial increase in stroke length. These results highlighted that stroke length and stroke index cannot be considered as the only parameters linked to improvement in a 200 m crawl in adult swimmers competing at high standard. Moreover, an increase in stroke rate associated with a slight decrease in stroke length should not be considered as ineffective, especially at top standard.

Effect of a 15% increase in preferred pedal rate on time to exhaustion during heavy exercise.

The aim of this study was to evaluate the effect of a 15% increase in preferred pedal rate (PPR) on both time to exhaustion and pulmonary O(2) uptake (VO(2)) response during heavy exercise. Seven competitive cyclists underwent two constant-power tests (CPT) at a power output that theoretically requires 50% of the difference in VO(2) between the second ventilatory threshold and VO(2)max (Pdelta50). Each cyclist cycled a CPT at PPR (CPTPPR) and a CPT at +15% of PPR (CPT+15%) in a randomized order. The average PPR value was 94 +/- 4 rpm, and time to exhaustion was significantly longer in CPTPPR compared with CPT+15% (465 +/- 139 vs. 303+/- 42 s, respectively; p = 0.01). A significant decrease in VO(2) values in the first minutes of exercise and a significant increase in VO(2) slow component was reported in CPT+15% compared with CPT(PPR). These data indicate that the increase of 15% PPR was associated with a decrease in exercise tolerance and a specific VO(2) response, presumably due to an increase of negative muscular work, internal work, and an altering of motor unit recruitment patterns.

Cadence and exercise: physiological and biomechanical determinants of optimal cadences--practical applications.

This critical review reflects the current state of cadence research during cyclical activities at different intensities. Moreover, this review aims at making suggestions in the areas of evaluation, therapy and sporting performance in the light of all the different results reported in studies. A large number of researchers have tried to determine the 'optimal' cadence from imposed, preferred or spontaneously chosen cadences in order to improve efficiency and performances. Results are sometimes conflicting and difficult to explain or interpret. The authors have studied the variations in cadences using a reduced number of parameters, without links between energetic (oxygen consumption, ventilation), biomechanical (force, electromyography) and/or perceived parameters (rating of perceived exertion). Conclusions point out that the 'optimal' cadence cannot be unique and must be associated with the objectives and individual characteristics of the subject (skills and training level, anthropometric parameters). In the area of training and reconditioning, cadences would have to be set in relation to the nature of cyclical activities and the subjects' condition.

Effect of incremental and submaximal constant load tests: protocol on perceived exertion (CR10) values.

The purpose of the present investigation was to determine to what extent the protocol (incremental and constant load exercises) affects the ratings of perceived exertion for a given submaximal intensity on a cycle ergometer. 10 healthy and well-trained male students (M age=23 yr., SD=2.9) performed an incremental exercise to determine maximal oxygen uptake (VO2 max), maximal aerobic power, and the ratings of perceived exertion (CR10) corresponding to 70% and 75% VO2 max (CR10(70i) and CR10(75i)). Two 30-min. constant load exercises set at these intensities were performed to establish the corresponding CR10 values. CR10(70i) (5.6 +/- 1.9) and CR10(75i) (6.2 +/- 1.9) were significantly higher than all CR10 values collected at Minutes 5, 10, 15, 20, 25, and 30 of the constant load exercises. These results indicate that, for a given exercise intensity (70% and 75% VO2 max), subjects are rated higher during an incremental exercise than during a 30-min. submaximal constant load test. Therefore, when coaches and physiotherapists want to use CR10 values reported during an incremental standard exercise to set training loads, they have to be prudent since the same relative exercise intensity does not seem to be perceived identically during a submaximal constant exercise as during an incremental one.

Cardiorespiratory and efficiency responses during arm and leg exercises with spontaneously chosen crank and pedal rates.

The aim of this study was to compare the cardiorespiratory and efficiency responses between upper (T(UBE)) and lower (T(LBE)) body exercises at the same relative power outputs and with spontaneously chosen crank (SCCR) or pedal (SCPR) rates. Twelve participants performed exercise bouts set at 20, 40, 60 and 80% of maximal power (MP) separated by passive recovery periods. Oxygen uptake, ventilation, gross and work efficiencies during T(LBE) were significantly (P < 0.05) higher than during T(UBE). These results suggest that these responses were not directly related to the relative intensities. However, no significant difference was found for delta efficiency and heart rate values. During T(UBE) and T(LBE), gross efficiency increased significantly (P < of MP for T(UBE) and T(LBE) and the same SCCR and SCPR could explain these results. The present results confirm that the cardiorespiratory and efficiency responses between arm and leg exercises are not always similar, although the power output are normalized in relation to MP and add to the understanding of differences between upper and lower body.

Ventilatory thresholds in arm and leg exercises with spontaneously chosen crank and pedal rates.

The present study assessed whether the first and the second ventilatory thresholds (VT1 and VT2) were dependent on the muscle groups solicited when spontaneously chosen crank and pedal rates are used. 20 physical education male students (22 +/- 2.2 yr.) performed two maximal incremental tests randomly assigned using an increment of 15 and 30 W every minute for arm and leg exercises, respectively. These tests were used to measure the maximal oxygen uptake (VO2 max) and to identify VT1 and VT2. The absolute oxygen uptake (VO2) values measured at VT1, VT2, and at maximal workload were significantly (p < .05) lower during arm and leg exercises. However, VT1 and VT2 expressed in percent of VO2 max were not significantly different between arm and leg exercises (54.1 +/- 8.2 vs 57.2 +/- 11.4%; and 82.5 +/- 6.4 vs 84.6 +/- 5.1% at VT1 and VT2, respectively). In addition, at the two thresholds, none of the variables measured during arm and leg exercises were significantly correlated with the exception of spontaneously chosen crank and pedal rates (p < .01; r = .75 and r = .69 for VT1 and VT2, respectively). Probably due to the different training status and skill level, no extrapolation can be made to specify the arm thresholds from the leg. These results underline the need to specify the ventilatory thresholds from specific arm ergometer measures obtained from tests performed with spontaneously chosen crank and pedal rates and, thus, close to sport and recreational activities, when they are used for training and rehabilitation programs.