Impaired jump landing after exercise in recreational and in high-performance athletes.

The risk of sustaining injuries increases with fatigue. The aim of this study was to analyze the influence of fatigue on dynamic postural control in jump landing and stabilization (ST) in athletes of different levels. In all, 18 high-performance ball sports athletes and 24 recreationally active subjects performed a jump test (JT) before and at 1, 5, 10, 15, and 20 minutes after a 30-minute treadmill run at the individual anaerobic threshold. An overhead ball switch hit during a forward jump triggered indicator lamps on either side of a force plate. After landing on the plate, ST on 1 leg (no light cue) or a second jump sideways (toward a light cue) was required. The ST force integral index was calculated for the ST trials. Dynamic postural control was significantly impaired in jump landing and ST in the first minute after the run: mean difference ± SD: 0.25 ± 0.48 m·s-1 (95% confidence interval: 0.10-0.40 m·s-1, p = 0.043; analysis of variance). No significant group differences were found. Under fatigued conditions, dynamic postural control in jump landing was impaired in an unexpected ST task. Not only recreational but also high-performance athletes were affected. Ball sports athletes could add a training exercise to their workout, which alternates between periods of high effort and neuromuscular training. Resistance to fatigue effects should be checked on a regular basis using JTs.

Subjective and objective results of arthroscopic debridement of ulnar-sided TFCC (Palmer type 1B) lesions with stable distal radio-ulnar joint.

PURPOSE: The purpose of this study was to determine functional and subjective results of patients who received arthroscopic debridement for their TFCC Palmer 1B lesions and to compare their results with those of arthroscopic suture repair. METHODS: Between March 2007 and August 2011, 36 patients were diagnosed with Palmer type 1B tears and underwent arthroscopic debridement. 31 patients (15 males and 16 females) were followed up for an average of 26.7 months (±17.4 months) postoperatively. Their average age was 36.7 years (±12.7 years). Follow-up included the determination of range of motion (ROM), grip strength, pain, and wrist scores (modified Mayo wrist score (MMWS), Disabilities of the Arm, Shoulder and Hand questionnaire (DASH score)). RESULTS: Postoperative ROM averaged 99.2 % for the extension/flexion arc, 95.5 % for the radial/ulnar deviation arc, and 99.4 % for the pronation/supination arc of motion when compared with the contralateral wrist. The MMWS was rated excellent in 48 % of patients, good in 39 %, fair in 13 %, and poor in 0 %. The average DASH score was 17.02 (±14.92). There was a significant reduction in pain. The grip strength was 96.7 % (±15.8), pulp-to-pulp pinch 101.9 % (±17.4), and the ulnar variance -0.12 ± 1.69 mm. CONCLUSIONS: Arthroscopic debridement of Palmer type 1B lesions in stable DRUJ yields satisfactory to excellent results. Our study showed similar results compared with the studies of arthroscopic suture repair with shorter postoperative care and fewer complications.

Altered force ratio in unanticipated side jumps after treadmill run.

OBJECTIVE: The aim was to investigate the influence of a run at the individual anaerobic threshold (IAT) on postural control in jumps with an unanticipated change of direction. HYPOTHESIS: Dynamic postural control is less affected by the run in trained athletes than in recreational ones. DESIGN: : Controlled prospective cohort study with an intervention. SETTING: Biomechanics laboratory. PARTICIPANTS: A total of 18 female high-level handball and volleyball players, 16 female and 8 male recreational athletes, with a mean age of 21.7 +/-4.1 years. INTERVENTIONS: In the jump test, the ball switch, hit above the force plate during a forward jump, triggers indicator lamps on either side. After landing on the dominant leg, a second jump 90 degrees sideways following a light signal or a stabilization in one-leg stance was required. Nine jumps (randomized order) were performed before and at 1, 5, 10, 15 and 20 min after a 30-min treadmill run at the IAT. MAIN OUTCOME MEASUREMENTS: For the second jump, the ratio of the absolute values of the maximum forces in anteroposterior and mediolateral direction was calculated as a parameter of dynamic postural control in the change of direction. RESULTS: In both groups, the force ratio increased significantly at 1 and 5 min after the treadmill run. The relative increase did not differ between groups. Dynamic postural control in transfer from a forward to a sideward jump was reduced after the run. Recovery occurred within 10 min. CONCLUSIONS: This study shows that dynamic postural control in jumps with an unanticipated change of direction is influenced by fatigue. These findings could be used to develop training programs aimed at reducing lower limb injuries in high-level ball sport athletes. The preventive effects have to be evaluated in further studies.

Determining knee joint alignment using digital photographs.

The objective of this work is to find out how reliably knee joint alignment can be measured from a standardized photograph and what influence changes in the standing position have on the angles measured. The interrater, intrarater, and test-retest reliability were evaluated. The influence of image-object distance, the distance between the legs and leg rotation on the measured angles was evaluated. In addition to the digital photographs, 10 full-length radiographs were obtained in an upright position to determine whether the measured angles represent the anatomic axis or mechanical axis. There was high correlation between the interrater (ICC 0.997), intrarater (ICC 0.989) and test-retest reliability (ICC 0.904). Only slight deviation was found with the changes in radiograph-object distance (0 degrees -1.8 degrees ). With feet together varus malalignment was greater. Leg rotation showed a strong influence on the measured results (ICC 0.658). The angle measured in the digital photographs reflects the mechanical axis with only slight deviation (0.12 degrees -1.9 degrees ). The measurement of the clinical axis using standardized radiography is highly reliable and can be used for individual follow-up of varus and valgus malalignments.