The profiles of single leg countermovement jump kinetics and sprinting in female soccer athletes.

The purposes were to evaluate kinetics in lower limbs using single leg countermovement jump (SLCMJ) and to identify the differences in SLCMJ kinetics between sprinting fast players and sprinting slow players in elite university female soccer players. Seventeen participants at the national tournament level completed the survey. SLCMJ and 30 m sprinting tests were performed. A force-plate was used to collect the data of the SLCMJ test. Significant differences of concentric maximum rate of force development (RFD), concentric RFD, concentric RFD/body weight (BW), peak net takeoff force/BW, peak power, and peak power/BW existed between both legs during the SLCMJ among all the participants. For further analysis, the participants were divided into fast group and slow group based on sprinting performance. Significant differences existed between the two groups in concentric peak velocity (nondominant, p = 0.028) and vertical velocity at takeoff (nondominant, p = 0.021). Concentric maximum RFD (p = 0.036) was significantly different between both legs in the slow group. Among elite university female soccer players, the players who presented more increased asymmetry of kinetic characteristics of jumping, also showed weak sprinting performance. Moreover, the players presented the best performance in velocity of the jumping variables and also had the best sprinting performance. Coaches and players should focus on keeping inter-limb balance and developing jumping velocity to improve sports performance. In future, the cause-and-effect relationship between jumping and sprinting should be identified.

Minimally invasive pedicle screw fixation, including the fractured vertebra, combined with percutaneous vertebroplasty for treatment of acute thoracolumbar osteoporotic compression fracture in middle-age and elderly individuals: A prospective clinical study.

ABSTRACT: To evaluate the feasibility, efficacy, and safety of minimally invasive pedicle screw (MIPS) fixation, including the fractured vertebra, combined with percutaneous vertebroplasty (PVP) for the treatment of acute thoracolumbar osteoporotic compression fracture in middle-age and elderly individuals.Between January 2016 and August 2019, a total of 30 patients, with a mean age of 69.4 years (range, 58-75 years), who experienced thoracic or lumbar fracture without neurological deficits, underwent the MIPS procedure combined with PVP. Preoperative and postoperative pain were assessed using a visual analog scale and Oswestry Disability Index. Cobb angles and anterior column height were measured on lateral radiographs before surgery and at 3 days, 1, 3, and 6 months, and 1 and 2 years at final follow-up after surgery.All patients underwent surgery successfully, with a mean follow-up of 18.2 ±â€Š5.7 months (range, 12-45 months). Mean preoperative visual analog scale score decreased from 7.3 ±â€Š2.2 to 1.4 ±â€Š0.3 at the final follow-up (P < .05). Mean preoperative Oswestry Disability Index decreased from 84.2 ±â€Š10.3 to 18.8 ±â€Š7.5 (P < .05) at the final follow-up. The Kyphosis angle of operative segment was improved from preoperative (21.38 ±â€Š1.68)° to (4.01 ±â€Š1.38)° 3 days postoperatively and (5.02 ±â€Š1.09)° at final follow-up (P < .05). The anterior vertebral height was improved from preoperative (49.86 ±â€Š6.50)% to (94.01 ±â€Š1.79)% 3 days postoperatively and (91.80 ±â€Š1.88)% at final follow-up (P < .05). No significant changes in vertebral body height restoration were observed during 2 years of follow-up after surgery. In addition, there were no instrumentation failures or complications in any of the patients.MIPS, including the fractured vertebra, combined with PVP, was a reliable and safe procedure, with satisfactory clinical and radiological results for the treatment of thoracolumbar osteoporotic compression fracture in patients without neurological deficits.

[Treatment of thoracolumbar fractures with unilateral pedicle screw fixation through paraspinal approach].

OBJECTIVE: To evaluate the feasibility and efficacy of unilateral pedicle screw fixation in treating thoracolumbar fractures through paraspinal approach. METHODS: From January 2006 to January 2009,21 patients with single level thoracolumbar fracture without neurological symptoms were treated with unilateral pedicle screw fixation through paraspinal approach. There were 14 males and 7 females,aged from 21 to 65 years old with a mean of 36.4 years. The duration from injury to operation ranged from 6 h to 5 d with an average of 3 d. According to the classification of Denis fracture, compression fractures happedned in 12 cases and burst fractures happened in 9 cases,including 1 case with T5 fracture, 2 cases with T7 fracture, 2 cases with T10 fracture, 3 cases with T11 fracture, 8 cases with T12 fracture, and 5 cases with L1 fracture. Based on the Flankel grade, all patients were classified as grade E. Anterior vertebral body height ratio, sagittal Cobb angle, condition of internal fixation failure, visual analogue score (VAS) were evaluated. RESULTS: All patients were followed up from 12 to 36 months with an average of 20.5 months. No internal fixation failure was found. Anterior vertebral body height ratios at preoperative 3 days after operation and last follow-up were 54.3 +/- 2.8, 92.9 +/- 1.5, 93.8 +/- 1.7, respectively;sagittal Cobb angle at the three timepoints were (27.8 +/- 2.5) degrees, (5.3 +/- 0.8) degrees, (6.3 +/- 1.4) degrees, respectively; the difference was statistical significant (P < 0.05). VAS was (1.2 +/- 0.4) points at last follow-up and had obviously improved (P < 0.05). CONCLUSION: Treatment of thoracolumbar fractures with unilateral pedicle screw fixation through paraspinal approach is safe with the advantages of micro-trauma and less blood loss,which can not only completely retain the posterior spinal complex structure, reinforce the spinal stability, raise the reductional quality, but also improve the strength of fixation and the distribution of stress force.

[Treatment of thoracolumbar fractures with short-segment transpediclar screw fixation and vertebroplasty via paraspinal intermuscular approach].

OBJECTIVE: To evaluate the clinical effects of short-segment transpedicular fixation and vertebroplasty via paraspinal intermuscular approach in treating thoracolumbar fractures. METHODS: From January 2009 to January 2012,18 patients with thoracolumbar fractures without neurological symptoms were treated with short-segment transpedicular fixation and vertebroplasty via paraspinal intermuscular approach. There were 11 males and 7 females, aged from 52 to 76 years old with an average of 62.2 years. The duration from injuries to surgery ranged from 8 h to 7 d with an average of 4.2 d. According to the Denis fracture classification, 12 cases got compression fractures and 6 cases got burst fractures. LOCATION: 6 vertebra with T12, 9 with L1, 6 with L2, and 3 with L3. Anterior vertebral body height, the sagittal Cobb angle, the sagittal index (SI), condition of internal fixation failure and recurrent kyphosis were observed. RESULTS: All patients were followed up for 12-28 months with an average of 16.5 months. Operation time was from 80 to 130 min with a mean of 95 min and bleeding volume during operation ranged from 100 to 180 ml with a mean of 145 ml. Anterior vertebral body height ratios preoperation, 3 days after operation and final follow-up was 54.3 +/- 2.8, 90.9 +/- 1.5, 88.6 +/- 1.7, respectively; sagittal Cobb angle was (27.8 +/- 2.5) degrees, (5.3 +/- 0.8) degrees, (6.3 +/- 1.4) degrees, respectively; sagittal index was 52.3 +/- 3.8, 89.2 +/- 5.2, 86.4 +/- 4.5, respectively. Data obtained 3 days after operation obviously improved than preoperation, and there was no statistically significant difference between 3 days after operation and last follow-up. No internal fixation failure, neurological complications and recurrent kyphosis were found. CONCLUSION: Treatment of thoracolumbar fractures with short-segment transpediclar screw fixation and vertebroplasty via paraspinal intermuscular approach can retain the posterior ligament complex and restore the mechanical strength of the anterocentral column,which proved an ideal method for preventing the failure of internal fixation and reduction of post-traumatic segmental kyphosis.