The effectiveness of lumbar extensor training: local stabilization or dynamic strengthening exercises. A review of literature.

BACKGROUND: Deconditioning of the lumbar extensor musculature (lumbar erector spinae and multifidus) is a risk factor for low back injury and pain. The article presents various aspects of scientific reports which confirm the effectiveness of lumbar extensor exercises. MATERIAL AND METHODS: The articles to be reviewed were extracted from the MedLine and PubMed data - bases. The following key words were used as search terms: lumbar multifidus muscle exercises, low back global exercise, motor control exercise in chronic low back pain, low back stabilization exercise. RESULTS: A number of prior investigations have described lumbar multifidus atrophy and replacement by fat after low back injury. Restoration of the tonic activity of the multifidus muscle is an essential condition in regaining health and spine functions. On the other hand, conditioning and strengthening exercises are considered valuable in effectively 'pre-habilitating' and reducing injury risk for athletes. CONCLUSIONS: 1. The lumbar low load specific stabilization exercises would be more efficient than muscle strengthening in the improvement of chronic low back pain. 2. Conditioning and strengthening exercises are considered valuable in effectively 'pre-habilitating' and reducing injury risk for athletes.

Abdominal muscle EMG-activity during bridge exercises on stable and unstable surfaces.

OBJECTIVES: To assess abdominal muscles (AM) activity during prone, side, and supine bridge on stable and unstable surfaces (BOSU, Swiss Ball). DESIGN: Prospective comparison study. SETTING: Research laboratory. PARTICIPANTS: Thirty-three healthy volunteers from a university population. MAIN OUTCOME MEASURES: Surface electromyography of the rectus abdominis (RA), the external oblique (EO) and the internal oblique with the transversus abdominis (IO-TA). RESULTS: The AM exhibited the highest activity during prone bridge on a Swiss Ball (RA, EO, IO-TA 44.7 ± 19.2, 54.7 ± 22.9, 36.8 ± 18.6 in % of MVC, respectively). The lowest activity was observed during supine bridge on a stable surface and a BOSU (under 5.0). The lowest ratio analyzed on the basis of the relation of EO and IO-TA activity to RA was obtained during prone bridge on the Swiss Ball (1.4 ± 0.7 for EO, 0.9 ± 0.5 for IO-TA). The highest ratio was obtained during prone bridge on stable surface and supine bridges. CONCLUSIONS: The highest level of activity in the abdominal muscles is achieved during prone bridge on a Swiss Ball. However, this exercise provided the lowest activity of the EO and IO-TA in relation to RA. It is essential to conduct further studies verifying the usefulness of using Swiss Ball during core stability training.

Incidence and risk for traumatic and overuse injuries in top-level road cyclists.

All traumatic and overuse injuries occurring during an average period of 4 years (2002/09) in a group of 51 currently active road top-level cyclists were retrospectively registered through clinical interviews. Average age was 25.8 years. Average training and competition period was 28.3 ± 2.4 h a week. Only 8 cyclists (15.6%) were completely free from lesions during the period of study. The remaining 43 cyclists suffered a total of 112 lesions; however, 9 out of these were unrelated to their cycling practice. These 103 cycling-related injuries include 50 (48.5%) traumatic and 53 (51.5%) overuse injuries. Twenty-eight fractures were reported, the clavicle being the most frequently affected bone (11 cases). The 68.5% of overuse injuries were located in the lower limbs. Most overuse injuries (89.6%) occurred during the training period. According to the injury abbreviated scale (AIS), severe lesions were only found in 4 cases (8% of traumatic injuries). Overall injury rates were 0.50 per racer/year, 2.02 per studied racer, and 0.007 per 1000 km of training and competition. Active professional top-level cyclists are exposed to a high injury risk. According to the scarce previously published data the current study provides relevant information on the injury occurrence of still active top-level road cycling.

Metabolic muscle damage and oxidative stress markers in an America's Cup yachting crew.

Activities of enzymes involved in muscle damage [creatine kinase (CK) and aspartate aminotransferase (AST)] and levels of malondialdehyde (MDA) as a marker of oxidative stress were monitored in the plasma of 27 members of an America's Cup yachting crew. The preventive benefits of allopurinol on muscle damage were also tested. In racing period A, the crew was divided into two groups according to their tasks on board. Blood samples from all 27 sailors were obtained before the start of a 5-day fleet race, after the last race, and after the ten match races. In period B, crew members were divided at random into two groups. One group (13 participants) received 300 mg/day of allopurinol 3 h before racing. The other ten members received placebo. Blood samples were collected just before and after the second round of the Louis Vuitton Cup. All participants showed increased CK and AST activities after the racing period A. The increase in CK activity was highest in sailors involved in strenuous physical work. At the end of period A, plasma MDA levels were higher in all participants as compared with non-participant athletes. In period B, a significant decrease in CK activity, but not in AST, appeared among participants receiving allopurinol. Plasma MDA decreased in sailors treated with allopurinol, but this reduction did not reach statistical significance. America's Cup is a sailing sport with high physical demands, as shown by the increase in muscle-damage markers. Treatment with allopurinol appeared to decrease the levels of muscle damage markers.

Mood profile of an America's Cup team: relationship with muscle damage and injuries.

PURPOSE: To describe the mood profile of an America's Cup sailing team during competition and to evaluate the influence of previous injuries occurrence and intensity of physical work on the boat upon mood state. Relationships between mood domains and metabolic markers of muscle damage were also investigated. METHODS: A descriptive study was conducted on an America's Cup yachting race crew comprising 21 male sailors (mean +/- SD; age = 27.6 +/- 8.5 yr, weight = 89.3 +/- 24.9 kg, BMI = 26.5 +/- 6.9 kg x m(-2)). All measurements were collected during the Louis Vuitton Cup 2007 in Valencia, Spain. The POMS test and creatine kinase (CK) serum activity were measured and correlated. Sailors were grouped according to their presence or absence of previous musculoskeletal injuries (MI) and the intensity of physical work related to boat position: high intensity (HI) and low intensity (LI). RESULTS: According to normative data, pre- and postracing POMS scores were constantly high with prominent anger (24.2 +/- 9 before and 24.9 +/- 10.1 after the race) and depression (22.7 +/- 8.9 before and 20.6 +/- 7.3 after the race). The HI group displayed unchanged anger scores but showed significant differences compared with the LI group (z = -2.07, P = 0.038, mu2 = 0.22) at the end of the competition. The occurrence of a previous injury did not correlate with any interference with mood. Only the fatigue domain before racing had a significant negative correlation with CK levels (r = -0.509, P < 0.05). CONCLUSIONS: The emotional profile of this America's Cup yachting crew showed stable mood scores with high values in anger and depression compared with normative data. Mood was dependent on physical work intensity related to boat position but not on injury occurrence. Enzyme markers of muscle damage had no bearing on most POMS domains, except for fatigue before racing.

Lesiones deportivas en los grinders de una tripulación de la Copa América durante 2004-2007 / Sports injuries in the grinders of an America´s cup sailing crew between 2004-2007

Objetivo: El propósito de este trabajo epidemiológico es describir de modo prospectivo las lesiones específicas ocurridas entre los grinders de una tripulación de Copa América durante las horas de competición. Métodos: Todas las lesiones sufridas por los 9 grinders de una misma tripulación fueron registradas durante las competiciones correspondientes a los 8 Actos de preparación (2004-2007) de la 32 ed. de Copa del América 2007 y la Copa Louis Vuitton. La edad media de los grinders se sitúa en 24,7 años (19-30). Las lesiones fueron clasificadas entraumáticas y por sobrecarga, agudas y crónicas. Se registraron la localización anatómica y el tipo diagnóstico de lesión. Resultados: En total se registraron 30 lesiones en 9 grinders. Un total de 6 tripulantes presentaron más de una lesión durante el estudio. La incidencia global fue de 9,09 lesiones/1000 horas de competición. Las lesiones por sobrecarga alcanzaron el 70% (nº:21) y las traumáticas el 30% (nº:9). Del total, 14 lesiones fueron clasificadas como crónicas, es decir, correspondieron a reactivaciones de antiguas lesiones. Se observaron 16 lesiones agudas o de nueva aparición. Del total de lesiones, el 50% se presentaron en la cintura escapular y en la columna cervical y el 30% en la extermidad superior. Según el tipo diagnóstico, las lesiones más frecuentes fueron las lesiones musculares funcionales (nº:15; 50%), seguido de sobrecargas articulares con sinovitis(nº:8; 26,7%) y las tendinopatías (nº:7; 23,3%). Conclusiones: El análisis prospectivo de las lesiones sufridas por los grinders durante America’s Cup indica que estos tripulantes tienen un alto riesgo de lesiones aunque su severidad es leve. Las lesiones se concentran en la cintura escapular, columna cervical y extremidad superior. Algún programa de prevención en esas localizaciones debería ser implementado en estos atletas (AU)

Objective: This epidemiological work was aimed at describing the specific injuries occurred in grinders of an America’s Cup yachting crew during competition hours throughout to the preparatory acts of the 32 nd America’s Cup 2007 and the Louis Vuitton Cup. Methods: All injuries suffered by sailors in grinder position were prospectively registered from October 2004 to June 2007. This period included 8 preparatory acts of the 32 nd America’s Cup 2007 and the Louis Vuitton Cup. There were 9 grinders with an average age of 24, 7 years (19-30). Injuries were classified as traumatic and secondary to overuse. Injuries were also considered either acute orchronic. Anatomic location of injury and the diagnosis type were registered. Results: A total of 30 injuries in 9 athletes were registered during the period of study. A group of 6 sailors showed more than one injury. None of the 9 grinders were free from any injury along the four competition years. Overall incidence was 9,09 injuries/1000 competition hours. Overuse injuries account for the 70% (nº:21) and traumatic for 30% (nº:9). The most common anatomic location was the shoulder girdle (50%), being the region most frequently affected. The most frequent injuries were found to be functional muscular injuries (nº:15; 50%), followed by joint injuries such as strains with synovitis (nº:8; 26,7%) and tendinopathies (nº:7; 23,3%). Conclusions: Grinders who participate in America’s Cup are exposed to a high risk of overuse injuries, although the severity of injuries is low. Specific programs for the most affected anatomic areas should be incorporated. This particular group should be included in strict monitoring programs for injury prevention and specific physical training (AU)

Different strategies for sports injury prevention in an America's Cup yachting crew.

PURPOSE: To analyze the effectiveness in reducing the number of sport injuries after application of different strategies of preventive physiotherapy during competition periods in an America's Cup yachting crew. METHODS: A prospective physiotherapy intervention study during competition periods for three seasons was conducted on an America's Cup yachting race crew of 30 professional sailors. In the first two acts (2004), athletes did not receive any preventive physiotherapy. In the two acts celebrated in 2005, preventive intervention (phase 1) consisted of stretching exercises before the yacht race and preventative taping. During the four acts corresponding to the 2006 season, the physiotherapy program was implemented adding articular mobilization before competition, ice baths after competition, and kinesiotaping (phase 2). In the last act and the Louis Vuitton Cup (2007), a recovery program with "core stability" exercises, postcompetition stretching exercises, and 12 h of compressive clothing were added (phase 3). RESULTS: In the preintervention phase (2004), the rate of injured sailors/competition day was 1.66, decreasing to 0.60 in 2007 (phase 3). The number of athletes with more than one injury was significantly reduced from 53% (8 of 15) to 6.5% (2 of 12). In the preintervention period, mastmen, grinders, and bowmen showed a rate of 2.88 injuries per competition day. After phase 3, this group only suffered 0.35 injuries per competition day. CONCLUSIONS: The implementation of a program of preventive physiotherapy decreased the risk of injuries suffered during competition by an America's Cup yacht crew.

Sports injuries in an America's Cup yachting crew: A 4-year epidemiological study covering the 2007 challenge.

The aim of this study was to describe the injuries sustained by an America's Cup crew during eight preparatory competitions of the 32nd America's Cup 2007 and the Louis Vuitton Cup (from October 2004 to June 2007). The anatomical location, type of injury, and mechanism of injury were recorded. The injuries were categorized based on each sailor's position on the boat according to three intensities of physical demands. The injury rates per sailor and per 1000 h of competition were determined. In total, 90 injuries were registered. The overall incidence was 10 injuries per 1000 competition hours. Overuse injuries accounted for 76.6% of all lesions. The most common anatomical location of injuries was the upper limb (36.6%), followed by the upper dorsal and cervical spine (34.4%). Frequency of injury was related to the sailor's position on the boat, being higher in the group with more demanding activities (grinder, bowman, and mastman). Most injuries (67%) were sustained by this group of sailors. The most common injuries in this group were muscle contractures of the quadratus lumborum (11), trapezius (8), and rhomboid (7). There were eight cases of elbow epicondylitis, four cases of tendinopathy of the supraspinous tendon, and three cases of tendinopathy of the biceps brachii. An America's Cup yachting crew is exposed to a high risk of overuse injuries, especially those sailors whose boat position involves high-intensity activity.