Hip and groin injury prevention in team sport

Steven Short is Vice President of Sports Medicine at the Denver Nuggets in the NBA. He recently published a paper, “Hip and groin injury prevention in elite athletes and team sport – current challenges and opportunities” and its this area that we dive into with Steven in this Sportsmith Six.

Range of motion is considered a “modifiable” risk factor for hip and groin injuries. But practically, what are some tests that can tell us anything meaningful? Are there any benchmarks that clinicians can use?

Range of motion tests have been standardized and been shown to be valid and reliable for a long time. The question to me is, what does a goniometric measurement tell us about the individual and their current state?

It’s well-established that athletes have “different” range of motion norms compared to non-athletic populations. This is likely specific to each sporting population, as a gymnastics hip will be different than a hockey hip, which will be different than a basketball hip. This does not allow us to make broad statements about hip mobility in general. Repeated measurements could show us how an athlete is evolving over time, or responding to their current training load or injury.

Acute competition, chronic competitive seasons and prior injury will all reduce hip range of motion scores. Often the purpose of preseason measurement of hip range of motion is to assess player risk and provide an intervention to reduce risk, but we lack repeated clinical follow-up.

Few trials show how modifiable and responsive hip range of motion is to interventions chronically (stretching, manual therapy, hip targeted exercise, etc.). It’s challenging to make broad statements on gaining or maintaining hip range of motion without overlooking morphologic considerations, such as the bony shape of the acetabulum or the shape of the head of the femur. Perhaps all we are doing is limiting how much motion we lose over time versus actually increasing range!

We need to appreciate how much mobility athletes can truly gain anatomically, and by which mechanisms they could do it. Are our interventions doing this, or is the sport and all other loads changing the range of motion? If we are providing mobility-based interventions (e.g., stretching, manual therapy), what evidence is there that we are creating lasting change to the hip joint as opposed to temporarily modifying the symptoms or neurophysiologic tolerance to a specific stretch.

For me, the benefit of assessing range of motion is in how it presents with or without musculoskeletal symptoms, how this evolves over time and its response to sporting activity or injury.

Strength is another risk factor, and one that seems to be investigated a lot in elite or collegiate sport. Adductor strength and adductor:abductor ratios seem to be the “go-to” assessments. Do you think these can guide us in understanding those players at risk on a daily basis, and do you have any benchmarks that you use in basketball?

The strength construct has more support in the literature as a modifiable and trainable risk factor compared to range of motion. However, there are still population-specific limitations to the value of the measurements.

When we evaluate risk, we unfortunately have to transfer strength studies from specific populations (soccer, hockey, rugby) to other sports. Based on unpublished data and experience, numbers in certain court-based sports will not hold up in terms of established normative data from other sports as relates to max force output and force ratios.

If you are able to get repeated measures on your athletes, you can time-stamp how they are responding to their demands. This may be assessing the effectiveness of off-season or preseason training to improve eccentric function; or it may be to evaluate how much strength they lose post-competition, and if they recover enough for their next bout of training or competition. Continuously obtaining objective data is time-intensive, but these strength measures are a way to track progress and potentially flag a lack of recovery in-season, thereby allowing a related intervention.

Practically speaking, a maximum effort isometric or eccentric brake test with a handheld dynamometer can give you quick insight within a competitive season and help you modify athlete programming accordingly. In a worst case scenario, having baseline strength data of any measure can assist in the return from injury process, as a practitioner will want objective goals to meet or exceed before returning to competition and hopefully accomplishing tertiary injury prevention.

Movement assessments and screens seem to be getting shot down a lot lately. Are there any movement assessments that you recommend that are easy to implement and don’t cost the world?

Clinic-based tools can provide valuable insight on athlete movement, but we need to temper our expectations of how effective they can be. There is plenty of evidence that athletes with hip pain, or a history of hip pain, will move differently than “healthy” athletes. Quick tests such as the Y-Balance Test- specifically, the posterolateral reach and anterior reach – can give you a nice insight on how the hip tolerates basic stressors. We can identify glaring asymmetries, and the Y-Balance / Star Excursion seems to hold up reasonable well with various reviews while still being very easy to implement in a field-based setting.

If you are able to combine this information with other measures such as range of motion, strength and symptom monitoring, you can evaluate interactions between these measures and basic movement.

Everyone wants a silver bullet to predict an injury from happening. We are not going to get that with movement assessment – injury is way too dynamic and complex. However, basic tests combined with other athlete interventions can give you acute and chronic insight on how an athlete tolerates basic joint and soft tissue stressors. It is our job to add up the pieces and apply some clinical reasoning to see if it is valuable for the athlete in front of us.

On a more dynamic level, doing a 505 test or a 110 degree change of direction and filming the mechanics can give you some insight similar to Enda King’s work published in 2018.

Perhaps these tests just tell you that an individual’s movement is responsive to pain or past injury, but I feel we can pry out a bit more insight if we take a single test, apply a healthy skepticism, and reason through it in combination with other bits of clinical information.

Monitoring high speed running and sprinting is now seen as a “vaccine” for hamstring injuries. Are there any particular metrics that we can use in a similar vein for hip and groin injuries?

Inherently this makes sense. We know various mechanics of hip and groin injury involve dynamic hip flexion: max effort jumping on a lay-up, kicking a ball and deceleration, that is, change of direction with high eccentric demand in a lengthening position like hip abduction. Monitoring athlete response to those mechanisms and training resilience in a “sport-specific” context seems reasonable.

However, we haven’t even figured out how to best use basic range of motion or strength data, let alone more complex movements and theories!

When it comes to these high intensity efforts, the biggest pearl I see is having a 6-12 week block prior to the season where athletes gradually train these efforts through their sport training. We can fill in the gaps via low volume repeat sprints, cuts and max effort jumps that reproduce these mechanisms within their conditioning programs if they aren’t getting enough on the court or field. But it will lack some of the competitive specificity that may be protective in the long run.

In your paper you have a heading, “Intervention over identification.” Are there any particular exercises or methods that you think should be used across almost all team sports when the goal is to reduce the chances of hip and groin injuries?

Despite all of our screening and testing, we all appreciate that predicting which athletes get injured and when is as elusive as the Sasquatch. You will go crazy if you dwell on non-modifiable risk factors, as the biggest intervention we have against them is education and acceptance of their reality and impact.

From established modifiable risk factors we can glean that proper sport-specific training / conditioning, load progressions through a preseason and adequate eccentric pre-season and in-season programs are things that we can program and attempt to control. They are exercise prescription fundamentals! Continuously monitoring these factors, the related interventions and dose-response allows us to make better decisions. They help us evaluate athlete response to stressors and globally reduce risk across a roster via secondary prevention.

The beauty of these tools are that everyone can benefit and you can implement them across the entire roster. By simply adding a group eccentric exercise program post-practice, you can protectively intervene across an entire group. Getting the group to train at an adequate sporting volume heading into the season and maintaining those gains via through training strategies benefits everyone.

This is a much more practical use of our time compared to trying to compute a magical individual algorithm from an 8-month old pre-season screen based on tests that haven’t been validated to prevent injury. You just need to ensure that you communicate the programming and the goals  across all departments to attain buy-in and adherence to these fundamentals.

What is the biggest mistake you see young practitioners or clinicians make, and what advice would you give them to help?

1. Be diligent with hip mobility drills and mindful of the athlete’s morphology or pathology. Sometimes scouring a hip makes it a lot more irritable and does not reduce their risk of injuring their groin!

2. Over-valuing a single intervention. It’s easy to hone in on a single bucket such as eccentric strength or just one specific movement test, and then become frustrated when you don’t get the outcome you are supposed to based on one factor or test. Especially if you only take this measure once in the pre-season.

It’s important to stay sound and fundamental with your training, and then use multiple data points to assist your clinical decision-making to modify program design per your findings.

Athletes have hip range of motion deficits, adaptable movement patterns and ever-changing strength profiles, and this is normal! We need to think through their entire profile and sport environment, and hopefully find a way to nudge them in the right direction.