山口大貴(鹿屋体育大学)，金高宏文(鹿屋体育大学)，山本正嘉(鹿屋体育大学)

本研究では，自転車競技におけるスポーツサークルの指導者である筆者が取り組んだ，自転車競技愛好者や競技者に対する運動技能指導において，SNSを利用した指導実践の報告を行うと共に，SNSを活用する指導のポイントについて提案した．1週間に1度の頻度で行うグループレッスンでは，時間的な制約のため，個人に対する声かけが不十分となり，指導者と参加者との間でトレーニングの解釈が合致していないという問題が生じていた．その問題点を解決するためにSNSを活用し，運動時の動画や意見を投稿するように促した．当初はSNSを開設し動画を掲載したが，それだけでは充分に活用されなかった．しかし，動画を観察するポイントを教授してからは，参加者同士でSNS上や実際に顔を合わせたレッスン時に意見交換をし合う，参加者同士の相互指導が行われるようになった．以上のことから，参加者と顔を合わせた指導時間に限りのあるグループレッスンでは，動画の自己観察を含むSNSの活用の仕方を教授すること，加えてSNS上での意見交換の監修や環境を調整することで，個人のトレーニングの課題の明確化や振り返り，参加者同士の相互指導や友好的なコミュニケーションを促進できると考えられた．

Using smartphones to coach a group in motor skills: Peer coaching among bicycling enthusiasts
The first author, who has been engaged in the training of bicycle racing enthusiasts and athletes in a sports club, tried a new coaching method that included the use of smartphones. At first, group lessons were given once a week, but there was not enough time for individual coaching, and there were discrepancies between the club members’ and the coach’s interpretations of the training. In an attempt to resolve these problems, the participants were urged to use their smartphones to post videos and their opinions. After that, however, only videos were posted, and they were not utilized well. Then, the coach explained to the club members the purpose of watching the videos, and encouraged the participants to do peer coaching on their smartphones or at the class meetings. This experience suggests that, in the group lessons with limited time, utilization of students’ smartphones for viewing videos, exchanging opinions, and making environmental adjustments may have promoted the definition and review of each individual’s problems, as well as encouraging peer coaching and friendly communication among participants.

村瀬直樹(中京大学), 堀山健治(中京大学), 桜井伸二(中京大学)

本研究は, 剣道の打撃動作において防御者に察知しづらいと思わせる動作特徴を明らかにすることを目的とした. 大学男子剣道部員32名を対象にアンケート調査を実施し, アンケート調査の結果から打撃動作が察知しづらい選手5名（上位群）および打撃動作が察知しやすい選手5名（下位群）を被験者として抽出し, 上位群および下位群それぞれの打撃動作のキネマティクス的特徴を明らかにした. その結果から察知しづらいと思わせる動作特徴として以下の項目があげられる. 1.踏み切り脚（左脚）の3関節を屈曲位な状態で構える. 2.打撃に至るまでの踏み切り脚の関節角度変位量を少なくする. 3.構えから打撃に至るまでの身体の上下動を少なくする. 以上の結果は即座に指導現場に還元でき, 指導する際の有益な知見になると考えられる.

Subjective speed of frontal striking movements in kendo
The aim of the present study was to identify characteristics of frontal striking movements in kendo that make it difficult for a defender to predict the strike. The members of a university kendo club (32 males) completed a questionnaire. From the results, 10 of the kendoka were selected: 5 kendoka whose strikes were difficult to predict (upper group) and 5 whose strikes were easy to predict (lower group). Kinematic features of the striking movements of those individuals were extracted. Features of the frontal striking movements that were found to be difficult to predict include the following: 1.The three joints of the step-in leg (left leg) are held in a flexed position. 2.The angle of displacement of the joints of the step-in leg is kept to a minimum until initiation of the strike. 3.Vertical movements of the body are kept to a minimum from the readiness stance until initiation of the strike. This information may be useful for kendo coaches..

フダラキス イオアニス ヨルギオス(鹿屋体育大学)，森寿仁(兵庫県立大学)，藤田英二(鹿屋体育大学)，山本正嘉(鹿屋体育大学)

本研究では，クロスフィットトレーニング（CFT）の運動強度の特性を明らかにすることを目的として，運動習慣を有する男性を対象にCFTの代表的な種目であるFranおよびCindy，フリーウエイトを用いたレジスタンストレーニング（RT）およびサーキットトレーニング（CT）を実施した際の心拍数，血中乳酸および筋活動水準について比較した．その結果，FranとCindyは共に心拍数および血中乳酸濃度が高強度領域に位置し，両課題間で有意差はみられなかった．筋活動水準については，外的な負荷を用いるFranでは多くの筋で高水準を示したのに対し，自体重負荷であるCindyでは多くが低水準を示し有意差が認められた．外的な負荷を用いるFranとRTとの比較では，筋活動水準には有意差は認められなかったが，心拍数および血中乳酸濃度はFranの方が有意に高かった．自体重負荷を用いるCindyとCTの比較では，心拍数，血中乳酸濃度および筋活動水準に有意差は認められなかった．以上のことから，FranではRTと同等の筋活動を発揮していることに加えて，有酸素性および無酸素性のエネルギー代謝にはより高い負荷がかけられていること，またCindyではFranやRTよりも筋活動水準は小さいが，CTと同様に有酸素性および無酸素性のエネルギー代謝には高い負荷がかけられていることが明らかとなった．

Exercise intensity characteristics of 2 of the benchmark CrossFit training workouts compared to traditional resistance training and circuit training: heart rate, blood lactate accumulation, and neuromuscular activity
The present study compared the exercise intensity characteristics of the CrossFit Training （CFT） benchmark protocols Fran and Cindy with those of traditional free weight resistance training （RT） and circuit training （CT） protocols. The participants were 7 physically active male university students. The measures were their heart rate, blood lactate accumulation, and neuromuscular activity in each exercise protocol. Both Fran and Cindy resulted in a high intensity exercise stimulus of the cardiovascular (heart rate) and metabolic systems (blood lactate accumulation). No statistically significant differences were found between workouts. On the other hand, the external load bearing protocol Fran resulted in a higher intensity stimulus to the majority of muscles tested, compared to the body mass bearing Cindy. Cindy resulted in statistically lower intensity stimuli. Furthermore, when the protocol Fran was compared to RT, Fran was found to result in a considerably higher exercise stimulus of the cardiovascular and metabolic systems, although no significant difference was found between the two protocols with respect to neuromuscular activity. Moreover, when the protocol Cindy was compared to CT, no significant difference was found in the measures of the aerobic, anaerobic, or muscle systems. These results suggest that Fran has a similar neuromuscular activity result as RT, but with a significantly higher impact on the cardiovascular and metabolic systems, whereas Cindy and CT have almost identical effects on all the physiological parameters measured in the present study.

中村夏実(鹿屋体育大学)，イスラム モハモド モニルル(鹿屋体育大学)，藤田英二(鹿屋体育大学)，榮樂洋光(鹿屋体育大学)，坂口陽平(鹿屋体育大学)，佐藤博幸(国立室戸青少年自然の家)，竹島伸生(朝日大学）

本研究の目的は，中高年者を対象にスタンドアップパドルボード（SUP）運動による静的および動的バランスに対する効果を検討することであった．「SUP健康教室」は，週１回，約２時間，全９回実施した．対象者は過去にSUPを行ったことのない男女９名（60.3±10.6歳）であった．教室前後で対象者のバランスを調べた．バランス測定には，バランスマスターを用い，静的バランスとして重心動揺速度（SV）を指標とし，動的バランスとして安定性の限界値（LOS）を指標とした．SVは，固い台（Firm）および柔らかい台（Foam）での開眼（EO）および閉眼時（EC）の条件で測定し，それらの総合変数（comp）で評価した．LOS は，初期到達点（EPE），最高到達点（MEX），反応時間（RT），重心移動速度（MVL）および方向制御（DCL）とした．テストは，８方向：前方（0度）; 右斜め前方（45度）; 右（90度）; 右斜め後方（135度）; 後方（180度）; 左斜め後方（225度）;左（L: 270度）; 左前方（315度）で計測し，それらの総合指標（comp）をデータとした. 「SUP健康教室」の結果，SVは，EC-Foamが約20％の改善，SVcompは17％改善した．EPEcompが6%，DCLcompが4%改善した．これらのことから，SUP運動における中高年齢者のバランスへの効果が示唆された．

Effects of stand-up paddle-board exercise on the balance of middle-aged and elderly people
The present study investigated effects of exercise utilizing a stand-up paddle board (SUP) on people’s balance. An SUP Health Class was held nine times, two hours per day, once per week. The participants were nine middle-aged and elderly people (3 men, 6 women; age 60.3 ±10.6 years) who had not done any stand-up paddle board exercises in the past. Before and after the SUP Health Classes, the balance of the participants was measured. The balancing indices included sway vision (SV) for stability balance and the limit of stability (LOS) for dynamic balance using a Balance Master. Sway vision was evaluated with the participant’s eyes open (EO) or closed (EC) while standing on a hard platform (firm) or a soft one (foam), and a composite value (comp) was calculated. The limit of stability included the initial attainable point (end point excursion, EPE), the highest attainable point (maximum excursion, MXE), the response time (RT), movement velocity (MVL), and direction control (DCL). Tests were conducted in eight directions: front (0 degrees), right front (45 degrees), right (90 degrees), right back (135 degrees), back (180 degrees), left back (225 degrees), left (270 degrees), and left front (315 degrees). The composite value was also calculated. After the SUP Health Classes, the participants’ static balance improved about 20% in the eye-closed-foam condition, and their sway vision composite value improved about 17%. Their dynamic balance improved about 6% in the end point excursion composite value, and the direction control composite value improved about 4%. These results suggest that stand-up paddle board exercise may have a positive effect on the balance of middle-aged and elderly persons.

中本光彦(中京大学), 細川正義(中京大学), 梶山俊仁(朝日大学), �ｱ濱星耶(中京大学), 小牧寛明(中京大学),山本知宙(中京大学), 藤川慎之介(中京大学), 種田行男(中京大学)

2019年にはラグビーワールドカップが日本で開催され，日本中でラグビーに対する注目度が著しく高まり，注目を集めている．今まさに，日本ラグビー界は，競技の普及・拡大に向けて重要な時期を迎えている．近年，ラグビー競技は安全性への配慮や，エキサイティングなゲーム展開となるようにルール変更が行われている．そこで，本研究は近年のスクラムに関するルール変更がゲーム様相に及ぼす影響を明らかにすることを目的とし，スクラムの回数やスクラムが組まれている時間などを調査した．調査対象は2016年度から2018年度のsix nationsでの試合映像から以下の項目を測定した．調査項目は1. スクラム数，2. スクラム時間，3. スクラムインプレー時間，4. 1試合の組み直し平均回数，5. スクラム内で反則がなかった割合であった．その結果，2018年におけるスクラムの組み直し回数と，スクラムインプレー時間は2016年および2017年に比べて明らかに減少していた．近年のルール改正によりスクラムに関する時間が減少傾向であることが示された．2017年のルール変更は，スクラムインプレー時間の短縮と組み直し回数の減少の効果があった.

Some results of the 2017 and 2018 rugby scrum law revisions
Because the Rugby World Cup was held in Japan in 2019, attention to rugby has recently increased greatly throughout Japan. As a result, Japanese rugby is now in a crucial phase for the popularization and expansion of competitions. World Rugby has been changing the rugby laws, aiming to increase the excitement of games while, at the same time, safeguarding the players’ safety. The purpose of the present study was to examine effects of the 2017 changes in the scrum laws on various aspects of the scrum, such as the total number of scrums and the number of scrums in-play time. From the game videos of six nations from FY2016 to FY2018, the following were measured: (a) total number of scrums, (b) total scrum time, (c) number of scrums in-play time, (d) average number of resets in a game, and (e) percentage of scrums without fouls. The average number of resets and the number of scrums-in play time were markedly fewer in 2018 than in 2016 and 2017. Another result of the law revisions was a decrease in scrum time.

山口大貴(鹿屋体育大学)，金高宏文(鹿屋体育大学)，山本正嘉(鹿屋体育大学)

自転車競技者であった筆者は，ペダリング運動中の荷重と脚の使い方を工夫することで，高いパフォーマンスを発揮できるこぎ方B（ペダル荷重×脚を踏み替える意識）を体得した．このこぎ方Bが機械的効率に優れることは，すでに本誌で報告した．本研究では，フォースプレートとインソールセンサーを用いることで，こぎ方Bと，それよりも効率の低い2つのこぎ方（A：ハンドル荷重×脚で踏みつける意識，C: サドル荷重×脚で踏みつける意識）との違いを可視化できるか，筆者1名を対象に検討した．荷重の様相については，自転車の前後車軸が2枚のフォースプレート上に乗るようにローラー台を設置し，前後の車軸に対して均等に荷重された場合にそれぞれ50%の値となるように設定した上で「荷重合成割合」を算出した．脚の使い方は，バイクシューズにインソールセンサーを装着し，足底圧力を算出することで可視化した．その結果，荷重合成割合の分布は，Aが47%（前寄り），Bが56%，Cでは63%（後寄り）の所に最頻値があり，分布の尖度はBが最も高かった．足底圧力は，Aは353N，Bが165N，Cでは351Nで，Bが他に比べて著しく小さかった．以上の結果から，荷重の仕方および脚の使い方の違いによって生じるペダリング技能の優劣を，客観的な指標で可視化できることが示唆された.

Objective visualization of pedaling technique in sport cycling: Comparison of tsechniques of loading and using the legs
The first author, who had been a bicycle racer, had developed a high performance using pedaling technique B (pedal loading x awareness of changing the pedaling leg) by improving how he loaded and used his legs while pedaling. The mechanical superiority of pedaling technique B has already been reported. The present study examined how to enable a cyclist to visualize differences between pedaling technique B and two less effective pedaling techniques, A (handle loading x awareness of stepping on the pedal with the feet) and C (saddle loading x awareness of stepping on the pedal with the feet). The participant was the first author. The differences of his results using the three techniques were measured with force plates and insole sensors. In order to calculate the load composite rate, a roller stand was installed in which the front and rear axles of a bicycle were supported by two force plates, and the weight was distributed equally to the front and rear axles. The cyclist was able to visualize how he used his legs and feet as a result of the installation of insole sensors in his shoes. With those sensors, the pressure on the soles of his feet could be calculated. The maximum frequency of the load composite rate was 47% (close to the side) with A technique, 56% with B, and 63% (close to the rear) with C. The highest kurtosis of the distribution was observed with B technique. The sole pressure was 353N with A technique, 165N with B, and 351N with C. In other words, the values observed with B technique were much smaller than with the other two techniques. These results suggest the possibility of using objective visualization of pedaling techniques with different loading methods and different ways that cyclists use their legs.

藤井雅文(鹿屋体育大学)，鈴木智晴(鹿屋体育大学)，佐藤伸之(鹿屋体育大学)，前田明(鹿屋体育大学)

本研究は，トラッキングシステムを用いた打撃パフォーマンステストから得られる打球データが，試合での打撃成績と合致しているか比較検討することで，本打撃パフォーマンステストの有用性を明らかにすることを目的とした．対象者は，A大学硬式野球部員の中で，春季公式戦に全試合出場し規定打席に達した3名とした．打撃パフォーマンステストは，バーチャルバッティングマシンから投じられる120km/hの直球を打ち返すフリー打撃を約60球 (約10球×6回：6週間) 実施した．本テストの打球データは，打球速度，打球角度，打球飛距離の3項目とし，打撃成績は，打率や長打率，本塁打数など17項目とした．両者を比較検討した結果，打球速度の平均値や変動係数と打率の関係が示され，打球角度から長打率や打球傾向がうかがえた．これらは，従来実施されてきたスイング速度だけの測定値では予測できなかった部分であり，トラッキングシステムによって取得することができた打球データの有用性を示す結果となった．従って，本打撃パフォーマンステストは打者を客観的に評価するのに効果的である可能性が示唆された．/p>

Evaluating batters objectively using data from a tracking system
The present study examined effectiveness of a batting performance test by comparing batting data from the test with results from a tracking system that recorded batting performance during games. The participants were 3 members of the A university baseball team who had taken part in all the official spring games and who met a criterion of number of times at bat. In the batting performance tests, the batters hit about 60 straight balls (about 10 balls x 6 times in 6 weeks) shot from a virtual batting machine at a speed of 120 km/h. The data collected from the performance test were measures of bat speed, bat angle, and distance traveled by the ball. Data obtained from the tracking system included 17 measures taken from the batters’ performance in games, such as batting average, slugging percentage, and number of home-runs. Comparison of the data from the batting performance test and the batters’ actual performance revealed the relation of bat speed and the coefficient of variation to batting average. The relation of slugging percentage and batting tendency to bat angle was estimated. These details could not have been obtained from the conventional measurement of swing speed. Thus, these results supported the usefulness of the data obtained with the tracking system. This suggests that the batting performance test may be effective for objectively evaluating batters.

下川美佳(鹿屋体育大学)，永原隆(鹿屋体育大学)，本嶋良恵(鹿屋体育大学)，金高宏文(鹿屋体育大学)，前田明(鹿屋体育大学)，竹中健太郎(鹿屋体育大学)

本研究では，右足踵部痛を改善させたある競技者の踏み込みに着目し，その事例から踏み込み動作とその動作による地面反力，踏み込み音の違いを検討して，技術指導に活用可能な示唆を得ることを目的とした．その結果，ある競技者の右足踵部痛改善の要因は，踏み込んだ瞬間に床面から右足が受ける衝撃力（地面反力）の低下であり，それには踏み込み脚大腿の挙上が低く，踏み込み脚中足趾節関節が底屈した踏み込みフォームへの動作修正が影響したものと推察された．また，踏み込み動作の修正とその力発揮の変容によって，踏み込み音が高く大きな音に変化し，打突評価が高まる可能性が示された．以上のことから，ある競技者が取り組んだ右足踵部痛を改善させるための踏み込み動作の変更は，傷害予防と競技力向上の両面において有効な技術修正といえる．

Changes in step-in action, ground reaction, and sound in order to lessen pain in the right heel: Analysis of how a kendoka reduced pain in the right heel
The aim of the present study was to identify useful ideas for kendo coaching by examining changes in step-in form, ground reaction, and step-in sound of a kendoka who had decreased the pain in the right heel. The retrospective analysis suggested that a key for decreasing the pain was to reduce impact that the right foot received from the ground by adjusting the step-in form such that the step-in thigh was lowered and the metatarsophalangeal joint of step-in foot was in planter flexion. These changes in step-in form and method of exerting power, which made the step-in sound louder, may lead to receiving a higher striking score. The analysis further suggested that the changes in step-in form that this kendoka applied in order to decrease the pain in the right heel may also be useful for preventing injury and improving competitive power more generally.

古川右京(鹿屋体育大学), 小原侑己(鹿屋体育大学), 山本正嘉(鹿屋体育大学)

筆者が所属するサッカーチームでは専属のトレーナーがおらず，怪我をした際に低下した体力を十分強化せずに競技復帰をして再受傷するケースが多い．本研究では，筆者が受傷したことを契機に，自身の体力を計画的に回復させ，より効果的な競技復帰を図った事例について報告した．受傷による痛みの消失後，現状把握のために体力・技術テストを実施したところ，いずれも大きく低下していた．そこで自身および指導者の意見，文献等を総合的に考察し，解決すべき能力に優先順位をつけた．その結果，持久力の改善を優先課題とした．　第1期ではLT走トレーニングを実施したところ，LT相当の走速度やYo-Yo Test(レベル1)は改善したが，復帰直後の練習ではダッシュを反復する際の持久力に課題を感じた．そこで第2期では高強度インターバル走を実施したところ，Yo-Yo Test(レベル2)の成績にも改善がみられ，試合のスタッツ，筆者自身の内省および指導者の内省報告でも肯定的な結果が得られた．この取り組みの手順は，トレーナー不在のチームで，選手が主体となって計画的に体力回復を図り，よりよい競技復帰を果たす上で，他選手の参考にもなると考えられた．

A stepwise recovery of endurance by a soccer player who was able to return safely to the game after a long time on the injured list
A soccer team that the first author participates in has no exclusive trainer, with the result that injured players often return to play before recovering sufficiently and, as a consequence, get injured again. The present study reports the first author’s experience in which he was injured but then exercised systematically in order to recover his strength, after which he was able to return safely to play. When the first author conducted physical and technical tests in order to have a better understanding of his physical condition after the pain from the injury had disappeared, he found that his scores on all the tests had decreased significantly. Then, on the basis of his own ideas, the coach’s opinion, and published articles, he prioritized the abilities that he should work on, giving the greatest emphasis to improvement in his endurance. In the first stage, after doing lactate threshold (LT) training, his running speed improved, as did his results on level 1 of the Yo-Yo Test, but he had only limited endurance in repeated dashes. In the second stage, he did high intensity interval runs, after which his results on level 2 of the Yo-Yo Test improved and his game stats showed positive results. That he had improved was also supported by his own and the coach’s feelings about his recovery. This approach may provide useful hints to other athletes who are on teams that have no trainer and who thus have to prepare on their own initiative a plan to recover their strength so that they can return safely to the game.

森祐貴(京都工芸繊維大学)，今井啓介(大阪学院大学)，渡邊和香(芦屋大学)

近年，2012年ロンドン五輪の女子バレーボール競技で金メダルを獲得したブラジル，銀メダルを獲得した米国がレシーバー枠を採用し，好成績につなげたことや2016年リオデジャネイロ五輪においても日本女子代表チームである真鍋ジャパンが12名の競技出場選手の中にレシーバー枠を採用し戦術の1つとして活用するなどメンバーチェンジによるリザーブメンバー出場の戦術的な有効性が再認識されている．そこで，本研究では，メンバーチェンジによるリリーフサーバー投入時に起こる得点変動が与える影響を明らかにすることを目的とした．これまで，試合に関する様々な要因から生み出された試合状況から判断される試合の主観的優劣とされていた「流れ」を今回，セット中のメンバーチェンジによるリリーフサーバー投入に着目することで意図的に「流れ」を獲得するための客観的な視点からのベンチワークに関する有用な知見を得ることに本研究を行う意義があるだろう．結論として，総ゲーム数147セット(61勝86敗)で勝率41.5%に対して，2回以上のサーブ継続がある場合には，76セット(42勝34敗)で55.3%と15%近く勝率が上昇した．

Influence of changes in scores due to consecutive serves on set wins and losses when a team uses a relief server: Examination of practice games
Recently, the silver-medal U.S. women’s volleyball team has adopted the receiver formation used by Brazil when winning a gold medal in women's volleyball at the 2012 London Olympics. Because of these favorable results, Masayoshi Manabe, coach of the Japan women's volleyball team, in the 2016 Rio de Janeiro Olympics, again proved the tactical effectiveness of adopting a receiver formation for a 12-player competition by using, among other strategies, mid-game substitutions of players. The aim of the present study was to examine the influence of score fluctuations when a relief server is introduced through player substitution. Until now, the flow of a game was considered to be a subjective measure of a team's performance and of the subsequent likely outcome, as judged on the basis of various game-related factors. The present research, conducted from an objective perspective, examined the results of coaching decisions that sought to develop flow intentionally by focusing on mid-game player substitutions with relief servers. An analysis of the results of practice games revealed a win rate of 41.5% across 147 sets (61 wins, 86 losses), whereas in cases of two or more consecutive serves, the win rate increased by nearly 15% across 76 sets (42 wins, 34 losses) to 55.3%.