When Manchester United and Chelsea face Viktoria Plzen and Astana respectively in Europe today, they will each have an England international full-back missing from their team sheet.United left-back Luke Shaw is injured again, and is devastated to be so. His struggles with recurrent injuries have had a huge impact on his career. Chelsea right-back Reece James is also hoping to make a full recovery from his latest lay-off and “come out on top. Against all odds.”As these players suffer further setbacks in their returns from unspecified muscle and hamstring injuries respectively, we asked Geoff Scott, former head of medicine and sports science at Tottenham Hotspur, to explain the general struggles and reasons for the delays.Luke ShawHe suffered a badly broken leg in 2015. Could that still be causing problems?Surprisingly, while it is a major injury, fractures usually heal well. What can be more problematic is if the fracture enters the joint, damaging joint surfaces, or a more complex situation where metalwork is required to stabilise the break. Shaw required surgery, indicating a more serious fracture, but normally you would still expect a good outcome.AdvertisementCould it have been the catalyst for injuries since then?The now 29-year-old does not seem to have suffered from the leg break itself since returning to play (after almost a full year out), but it could have contributed to the recurrent muscle injuries that have kept him out since then. The recovery period following a fracture can result in significant deconditioning. As the injury heals, reconditioning is required, with progressive increased activity until the player reaches pre-injury levels and can return to team training and match play. Residual weakness from a previous injury can also cause muscle strength imbalance and increased risk of injury in the weaker muscle. Statistically, during this time the player is at greater risk of re-injury. Shaw is on the recovery trail, again (Charlotte Tattersall – MUFC/Manchester United via Getty Images)To add to this, when one injury follows another, the cumulative time lost can have a compounding effect with players picking up more frequent problems. For Shaw, these have been with his hamstring and calf muscles. Such issues are seen in a higher proportion in faster players — and also in full-backs and wingers who have higher physical demands due to greater distances run in matches compared with their team-mates.Would the new manager at United have made a difference?The “new manager effect” is often associated with a positive bounce in results. However, it can also have a negative effect on injuries. This happens because players may be asked to adopt a new style and pace of play which places different physical demands on their bodies and there can be a knock-on effect until they adapt. Another reason for worsening injuries is that new managers are frequently appointed in response to a dip in results; so a replacement in the dugout is a fresh start, with a heightened desire to improve performances and to work even harder than before for the new coach. Professional footballers are very well conditioned but, as they are constantly working near the maximum of their physiological capacity, it doesn’t take much extra to push them into dangerous training zones. This period needs to be planned well and progressively increased. AdvertisementThe timing of Shaw’s latest injury, days after the arrival of Ruben Amorim as head coach, is an unlucky coincidence. But it is recognised that a change in training and playing style has a significant impact on injuries in the first few weeks and months. This is why it is so crucial for the new manager and his new coaching team to work with the medical and performance department to effectively manage players’ workload and ensure they are rotated during busy match schedules to optimise their performance. Failure to do so could put their players at risk — particularly of muscle and soft-tissue injuries. Amorim is United head coach after Erik ten Hag was sacked in late October (Clive Brunskill/Getty Images)Reece JamesWhy does he continually get hamstring problems?Hamstrings constitute 24 per cent of all injuries in men’s professional football. According to Ben Dinnery, who runs the Premier Injuries website, there have been 53 hamstring-related absences in the top flight this season, which have accounted for 42 per cent of all muscle injuries (a figure which hasn’t changed a great deal year on year). While they have always been a burden on teams, recent years have shown a significantly increased incidence — and the average time lost per hamstring injury has almost doubled due to a worsening severity. The reasons for this are not completely understood, but are most likely due to changes in the game. Recorded physical statistics, taken from GPS data in training and matches, show increases in speed of play, sprinting distances and the number of accelerations and decelerations putting more demand on athletes’ bodies. James is more susceptible to hamstring injuries because of his previous problems (Carl Recine/Getty Images)James has a top speed of 36.6km/h (22.7mph), which puts him towards the high end of players in the Premier League. As a right-back, the 25-year-old is required to produce some of the biggest physical outputs in the team, for total distance and high-speed running metrics. For a player such as James, who has a history of repeat hamstring injuries, this can put him at risk of repeat problems. The most significant risk factor for hamstring strains is having had a previous injury of that kind. It is required to tolerate significant forces while sprinting, often at the end of its physiologic range (full stretch) — and when there has been a previous injury, there is often a build-up of scar tissue within the muscle. This means it does not stretch in quite the same way and it can become a weak point within the muscle itself. Like a rope with a small defect, the area of scar tissue is likely to fail again once a certain amount of load is applied.AdvertisementJames is out “for a number of weeks” with his latest problem. He will return to the highest levels of match play in time but the problem he and his team will face is his susceptibility to further injury.What is the best way to manage a player in this situation? The most important aspect when managing a player who has had frequent injuries is to appropriately control their loads and ensure effective recovery following each session. The period before they return to first-team action can be the most dangerous as the player becomes anxious to contribute — and the team may need him. But this is where there must be a level of patience to be sure he or she can perform at the highest level repeatedly. Thankfully, this can be achieved through the barrage of testing and monitoring that is available at clubs to assess players’ status. For example, assessing the strength of the hamstring muscle and comparing it to pre-season baseline levels and the contralateral side (the uninjured leg) can ensure the muscle condition is optimised. This is an area that has performance teams working relentlessly to mitigate against any potential risk factors.Good communication and respect between coaching and medical staff at each stage are crucial. Once training is resumed with team-mates, the athlete gets placed in more physically challenging situations, responding to the demands of competition. This period lifts their confidence, builds the muscle’s tolerance to fatigue and allows the coach to see when the player can return to the performance level required to help the team in matches. For the athlete, however, the work does not stop there; their dedication to recovery and continued programme of strengthening and mobility will continue before and after training each day for months to come, with the aim of preventing further recurrence. Each session throughout the week will serve a different purpose, aiming to arrive on gameday with the right amount of loading completed, while still feeling fresh to perform optimally in the match. (Top pictures: Getty Images)

When Manchester United and Chelsea face Viktoria Plzen and Astana respectively in Europe today, they will each have an England international full-back missing from their team sheet. United left-back Luke Shaw is injured again, and is devastated to be so. His struggles with recurrent injuries have had a huge impact on his career. Chelsea right-back […]

When Manchester United and Chelsea face Viktoria Plzen and Astana respectively in Europe today, they will each have an England international full-back missing from their team sheet.

United left-back Luke Shaw is injured again, and is devastated to be so. His struggles with recurrent injuries have had a huge impact on his career. Chelsea right-back Reece James is also hoping to make a full recovery from his latest lay-off and “come out on top. Against all odds.”

As these players suffer further setbacks in their returns from unspecified muscle and hamstring injuries respectively, we asked Geoff Scott, former head of medicine and sports science at Tottenham Hotspur, to explain the general struggles and reasons for the delays.

Luke Shaw

He suffered a badly broken leg in 2015. Could that still be causing problems?

Surprisingly, while it is a major injury, fractures usually heal well. What can be more problematic is if the fracture enters the joint, damaging joint surfaces, or a more complex situation where metalwork is required to stabilise the break. Shaw required surgery, indicating a more serious fracture, but normally you would still expect a good outcome.

Could it have been the catalyst for injuries since then?

The now 29-year-old does not seem to have suffered from the leg break itself since returning to play (after almost a full year out), but it could have contributed to the recurrent muscle injuries that have kept him out since then.

The recovery period following a fracture can result in significant deconditioning. As the injury heals, reconditioning is required, with progressive increased activity until the player reaches pre-injury levels and can return to team training and match play. Residual weakness from a previous injury can also cause muscle strength imbalance and increased risk of injury in the weaker muscle. Statistically, during this time the player is at greater risk of re-injury.

Shaw is on the recovery trail, again (Charlotte Tattersall – MUFC/Manchester United via Getty Images)

To add to this, when one injury follows another, the cumulative time lost can have a compounding effect with players picking up more frequent problems. For Shaw, these have been with his hamstring and calf muscles. Such issues are seen in a higher proportion in faster players — and also in full-backs and wingers who have higher physical demands due to greater distances run in matches compared with their team-mates.

Would the new manager at United have made a difference?

The “new manager effect” is often associated with a positive bounce in results. However, it can also have a negative effect on injuries. This happens because players may be asked to adopt a new style and pace of play which places different physical demands on their bodies and there can be a knock-on effect until they adapt.

Another reason for worsening injuries is that new managers are frequently appointed in response to a dip in results; so a replacement in the dugout is a fresh start, with a heightened desire to improve performances and to work even harder than before for the new coach. Professional footballers are very well conditioned but, as they are constantly working near the maximum of their physiological capacity, it doesn’t take much extra to push them into dangerous training zones. This period needs to be planned well and progressively increased.

The timing of Shaw’s latest injury, days after the arrival of Ruben Amorim as head coach, is an unlucky coincidence. But it is recognised that a change in training and playing style has a significant impact on injuries in the first few weeks and months. This is why it is so crucial for the new manager and his new coaching team to work with the medical and performance department to effectively manage players’ workload and ensure they are rotated during busy match schedules to optimise their performance. Failure to do so could put their players at risk — particularly of muscle and soft-tissue injuries.

Amorim is United head coach after Erik ten Hag was sacked in late October (Clive Brunskill/Getty Images)

Reece James

Why does he continually get hamstring problems?

Hamstrings constitute 24 per cent of all injuries in men’s professional football. According to Ben Dinnery, who runs the Premier Injuries website, there have been 53 hamstring-related absences in the top flight this season, which have accounted for 42 per cent of all muscle injuries (a figure which hasn’t changed a great deal year on year).

While they have always been a burden on teams, recent years have shown a significantly increased incidence — and the average time lost per hamstring injury has almost doubled due to a worsening severity. The reasons for this are not completely understood, but are most likely due to changes in the game. Recorded physical statistics, taken from GPS data in training and matches, show increases in speed of play, sprinting distances and the number of accelerations and decelerations putting more demand on athletes’ bodies.

James is more susceptible to hamstring injuries because of his previous problems (Carl Recine/Getty Images)

James has a top speed of 36.6km/h (22.7mph), which puts him towards the high end of players in the Premier League. As a right-back, the 25-year-old is required to produce some of the biggest physical outputs in the team, for total distance and high-speed running metrics. For a player such as James, who has a history of repeat hamstring injuries, this can put him at risk of repeat problems.

The most significant risk factor for hamstring strains is having had a previous injury of that kind. It is required to tolerate significant forces while sprinting, often at the end of its physiologic range (full stretch) — and when there has been a previous injury, there is often a build-up of scar tissue within the muscle. This means it does not stretch in quite the same way and it can become a weak point within the muscle itself. Like a rope with a small defect, the area of scar tissue is likely to fail again once a certain amount of load is applied.

James is out “for a number of weeks” with his latest problem. He will return to the highest levels of match play in time but the problem he and his team will face is his susceptibility to further injury.

What is the best way to manage a player in this situation?

The most important aspect when managing a player who has had frequent injuries is to appropriately control their loads and ensure effective recovery following each session. The period before they return to first-team action can be the most dangerous as the player becomes anxious to contribute — and the team may need him. But this is where there must be a level of patience to be sure he or she can perform at the highest level repeatedly. Thankfully, this can be achieved through the barrage of testing and monitoring that is available at clubs to assess players’ status. For example, assessing the strength of the hamstring muscle and comparing it to pre-season baseline levels and the contralateral side (the uninjured leg) can ensure the muscle condition is optimised. This is an area that has performance teams working relentlessly to mitigate against any potential risk factors.

Good communication and respect between coaching and medical staff at each stage are crucial. Once training is resumed with team-mates, the athlete gets placed in more physically challenging situations, responding to the demands of competition. This period lifts their confidence, builds the muscle’s tolerance to fatigue and allows the coach to see when the player can return to the performance level required to help the team in matches. For the athlete, however, the work does not stop there; their dedication to recovery and continued programme of strengthening and mobility will continue before and after training each day for months to come, with the aim of preventing further recurrence.

Each session throughout the week will serve a different purpose, aiming to arrive on gameday with the right amount of loading completed, while still feeling fresh to perform optimally in the match.

(Top pictures: Getty Images)