Senior Club-Level Rugby Union Player's Positional Movement Performance Using Individualized Velocity Thresholds and Accelerometer-Derived Impacts in Matches.

ABSTRACT: Takamori, S, Hamlin, MJ, Kieser, DC, King, D, Hume, P, Yamazaki, T, Hachiya, M, and Olsen, PD. Senior club-level rugby union player's positional movement performance using individualized velocity thresholds and accelerometer-derived impacts in matches. J Strength Cond Res 36(3): 710-716, 2022-Game demands of professional rugby union players have been well documented; however, there is minimal game demand information using individualized velocity thresholds and collision loads, particularly for amateurs. This study investigated movement patterns of 20 male amateur rugby players during 16 senior premier division one matches using global positioning system (GPS) devices sampling at 10 Hz. Derived GPS variables included distances, velocities, sprinting, and impacts. Data files from 86 player games (≥60 minutes of play per game) were categorized into broad (forwards and backs) and specific (front row, second row, back row, half back, inside back, and outside back) positional groups for analysis. It was most likely that backs covered more distance in the high-speed running (>60% maximal velocity) zone (502 ± 157 m) compared with forwards (238 ± 147 m) (100/0/0%, chances of positive/trivial/negative differences, effect size [ES] = 1.3), performed more striding (backs 1,116 ± 240, forwards 954 ± 240 m, 96/4/0%, ES = 0.5), and sprinting (backs 121 ± 58, forwards 90 ± 65 m, 93/7/0%, ES = 0.5). However, forwards had higher collision loads (35 ± 12 arbitrary units) compared with backs (20 ± 6, 99.9/0.1/0%, ES = 1.3) with back row forwards completing the highest collision load of any playing position (40 ± 13). Our example match movement performance and impact information is valuable to coaches and support staff in preparing player profiles for similar-level rugby players to help manage their workloads.

Intraoperative Neural Mobility and Postoperative Neurological Recovery in Anterior Cervical Decompression Surgery: Evaluation With Intraoperative Sonography.

STUDY DESIGN: A study using intraoperative sonography (IOS) was conducted for evaluating neural mobility in anterior cervical decompression surgery. OBJECTIVES: To analyze decompression status and mobility of the spinal cord and the nerve root during anterior cervical decompression and to clarify its relevance to the postoperative neurological recovery. SUMMARY OF BACKGROUND DATA: Several papers introduced the usefulness of IOS assessments; however, there have been no reports systematically evaluating the neural mobility in anterior cervical decompression surgery. METHODS: Eighty-four consecutive patients with compressive myelopathy who underwent anterior cervical decompression procedures were studied. The decompression status of the spinal cord was evaluated with IOS and classified into 3 grades according to the restoration pattern of the space ventral to the cord. Pulsatile motion of the spinal cord in cranio-caudal direction was named "sliding pulsation" and graded into 3 groups. The nerve root pulsation was also assessed using the IOS short-axis views. This study analyzed whether those neural mobility in anterior cervical decompression surgery had relevance to postoperative neurological recovery, which was assessed by the Japan Orthopaedic Association score. RESULTS: The mean recovery rate of the Japan Orthopaedic Association score was 59.1% in total. According to the decompression status in IOS, 67 patients who acquired space ventral to the spinal cord indicated 64.3% of the recovery rate which was significantly higher than 36.6% of the other patients on an average. As to the sliding pulsation of the cord, 10 patients who failed to show this particular motion indicated significantly lower recovery rate as 36.9%. In addition, 6 patients who did not exhibit nerve root pulsation indicated just 29.3% of recovery rate, and 4 of them failed to show the cord sliding motion. CONCLUSIONS: Sonographic evaluation during anterior cervical decompression surgery provided very useful information of neural decompression status that had significant correlation with postoperative neurological recovery.

A new performance test for cervical myelopathy: the triangle step test.

STUDY DESIGN: Our original performance test for evaluating the severity of cervical myelopathy, the triangle step test (TST), was introduced along with an assessment of its validity. OBJECTIVE: The TST was designed to evaluate the lower extremity motor function objectively and quantitatively. This study aimed to assess the validity of the test by analyzing the relation to the other analytic methods. SUMMARY OF BACKGROUND DATA: Several rating scales and performance tests have been proposed to evaluate the severity of cervical myelopathy. Simple walking test is useful; however, the test is limited for the patients who can walk safely. METHODS: Each subject sitting on a chair was instructed to step on marks at each apex of a triangular board and the number of steps in 10 seconds was counted for each foot. The subjects were 270 cervical myelopathy patients who had visited our hospital since 2002. As a control group, 60 healthy adults also underwent this test. All subjects were simultaneously evaluated by the Nurick score, the Japan Orthopedic Association score and the finger grip and release test. An assessment of the effect of surgery was analyzed for 94 patients who underwent surgical treatments. RESULTS: The mean of the lower count for each subject (TST score) in the control group was 25.4 +/- 3.7 steps, which was superior to 18.4 +/- 5.2 steps for myelopathy patients. TST score significantly correlated to the other analytic measures for cervical myelopathy. Regarding the effect of surgery, a performance of 16.7 +/- 4.5 steps before surgery improved to 21.2 +/- 4.9 steps at follow-up. Patients who could step more than 20 times before surgery, showed greater neurologic recovery. CONCLUSION: TST score correlated with other analytic methods for cervical myelopathy. This test is very useful to quantitatively evaluate lower extremity function and its improvement following surgical intervention.

Spinal cord morphology and dynamics during cervical laminoplasty: evaluation with intraoperative sonography.

STUDY DESIGN: An intraoperative sonographic study for evaluating spinal cord decompression status was conducted. OBJECTIVES: To analyze the spinal cord decompression status using intraoperative sonography and to evaluate the relation to postoperative neurologic recovery following cervical laminoplasty. SUMMARY OF BACKGROUND DATA: Since the 1980s, several papers have introduced that the intraoperative ultrasound allowed assessment of the adequacy of decompression and configuration of the spinal cord in compressive myelopathy. However, there have been no reports systematically evaluating the decompression status. METHODS: Spinal cord decompression status of 80 consecutive patients with cervical compressive myelopathy was evaluated by intraoperative sonography during cervical laminoplasty. The decompression status was classified into 4 grades according to the restoration pattern of the space ventral to the cord. In addition, amplitude of the cord pulsation and compression type in axial view were also assessed. This study analyzed whether those findings from intraoperative sonography had relevance to preoperative spinal cord conditions evaluated by magnetic resonance images (MRI) and postoperative neurologic recovery. RESULTS: The mean neurologic recovery rate was 48.3% at the final follow-up. According to intraoperative sonographic evaluation, 50 cases who acquired the space ventral to the cord showed significantly higher recovery rate (59.2%) than 30 cases who failed to acquire the space (recovery rate, 31.0%) in total. Twenty-seven of 60 cases with intramedullary T2 high lesion on preoperative MRI more frequently failed to restore the ventral space, and their neurologic recovery rate indicated 30.2%. The amplitude of spinal cord pulsation or compression type did not correlate with the neurologic recovery. CONCLUSION: Intraoperative sonography during laminoplasty appears to be very useful for evaluating spinal cord decompression status. Our original classification system based on restoration patterns of the space ventral to the spinal cord is considered to be practical for predicting neurologic improvement in cervical compressive myelopathy.