This past season both Jeremy Lin and Andre Roberson suffered a patellar tendon rupture. This is a rare injury that accounts for only 6% of tendon ruptures in total. Most patellar tendon rupture occurs in individuals older than 65.
Here are videos of the Lin and Roberson patellar tendon rupture (hate the cover images but oh well):
Through my unique lens as a Doctor of Physical Therapy (DPT) and avid sports fan, I’ll answer the following questions:
- What is the anatomy and function of the patellar tendon?
- What happens during a patellar tendon rupture?
- What caused Lin and Roberson to suffer a patellar tendon rupture?
- What are the common symptoms of a patellar tendon rupture?
- What does surgery for a patellar tendon rupture entail?
- How are Lin and Roberson rehabbing?
- Are there any long-term implications?
I. The anatomy & function of the patellar tendon
The patellar tendon connects the bottom of the patella (the kneecap) to the tibia (the shin bone). Here’s what it looks like, also take note of the surrounding anatomy:
The patellar tendon, along with the patella (kneecap), quadriceps tendon, and quadriceps, is part of the extensor mechanism of the knee – they work in conjunction to straighten the knee and eccentrically control (“brake”) knee flexion (bending).
In the following video, you can how the patellar tendon elongates and controls knee bend:
Each time your knee has to straighten or bend, the patellar tendon is loaded. For a reference point, the simple act of going up stairs loads the patellar tendon with 3x your body weight. Just imagine how much load is going through the patellar tendon during dynamic activities like jumping and landing.
Now that we know the anatomy, what actually happens during a patellar tendon to rupture?
II. What happens during a patellar tendon rupture
Generally, a very strong force is required to tear a tendon – nearly 17 times your body weight. For the patellar tendon, the most common mechanism for a rupture is when the foot is planted, the knee is bent, and there’s a strong, sudden initiation of the extensor mechanism (in athletic populations, this most commonly occurs during landing). This combination of events results in a strong, sudden contraction of the patellar tendon under heavy resistance and mechanical disadvantage.
To understand mechanical disadvantage, think about doing a biceps curl. The hardest part of the curl is when your arm is straight down by your side and you’re trying to bring it up – at this point, the biceps is elongated and at a mechanical disadvantage.
To apply this to the patellar tendon, lets look at the video again from up top:
You can see that as the knee bends, the patellar tendon elongates which decreases it’s extension mechanical advantage.
Moving on, a patellar tendon tear can either be incomplete or complete (full rupture). An incomplete tear is like a rope being stretched where some of fibers fray but the rope is still intact. A complete tear is when that rope frays and snaps.
With a complete patellar tendon rupture, the tendon itself tears away from the kneecap. Here’s a work-safe visual:
The tendon is completely separated form the kneecap and you can’t straighten your knee.
III. What caused Lin and Roberson’s patellar tendon rupture
There are different risk factors and mechanisms that can lead to a patellar tendon rupture. Generally, an already weakened tendon is more likely to rupture. This weakness could be from ongoing patellar tendonitis (often referred to as “jumpers knee”) or chronic diseases like diabetes or metabolic syndrome (which could explain why patellar tendon ruptures are far more commonly seen in older individuals). In either case, the result is disorganized and weakened tissue with micro-tears in the patellar tendon.
In the case of Lin and Roberson, I’d be shocked if either was suffering from chronic disease so lets rule that out. Additionally, I couldn’t find any history of Lin having patellar knee problems but Roberson did. I’ve listed out the dates and injury description given by OKC:
- 10/15/16 – left knee soreness
- 4/06/17 – left knee soreness
- 12/31/17 to 1/15/18 – missed 8 games with left knee patellar tendonitis
Clearly there’s a history of left knee problems with Roberson and I wouldn’t be surprised at all if that earlier soreness was also patellar related since he eventually missed significant time dealing with left patellar tendonitis.
Lastly, Roberson also missed 2 games with a sprained left ankle in mid-December of 2017. This is also a risk factor because the foot and ankle are key to absorbing force whenever your foot hits the ground. Impaired force absorption at the foot results in a bigger shockwave traveling up through the leg, including into the patellar tendon.
The lack of injury history in Lin’s case and existing injury history in Roberson’s case also makes sense when we examine their specific mechanisms for injury. Speaking of which…
A. Lin’s mechanism of patellar tendon rupture
Jeremy Lin’s patellar tendon rupture occurred from a huge force on his patellar tendon while landing. Let’s use a series of pictures to break it down:
- First, Darren Collison puts a slight shove into Lin’s back as he goes up to elevate
- Second, Lin is trying to finish in traffic between two players and rotates in the air
These details are important to take note of because each challenges and affects Lin’s sensory systems, specifically his proprioceptive and vestibular systems.
These systems are responsible for providing feedback to his brain about where his body is in space. Based on this feedback, the brain makes little adjustments and activates certain muscles to make movement more efficient, effective, and safe.
In Lin’s case, the slight nudge from behind combined with the flurry of activity may have compromised his sensory systems.
Now, here’s a picture of his landing (look at the right knee):
Three things to note here:
- Landing puts a load on the patellar tendon because it has to first eccentrically control (“brake”) knee flexion (bending) and then keep the body upright by extending (straightening) the knee.
- Lin lands on one leg. This puts even more load on his right patellar tendon (and all other parts of the leg as well) to help control knee bending and then straighten the knee
- Jeremy’s knee is significantly flexed (bent) when his foot is planted (probably because he’s falling backward when he lands). This puts a large resistive load on the patellar tendon – in fact, the largest load on the patellar tendon is when the knee is bent past 60 degrees. Lin’s knee is near or past 60 degrees.
When you combine these extreme mechanical stresses on the patellar tendon with a reduced “safety buffer” from the compromised sensory systems, it’s a recipe for disaster.
B. Roberson’s mechanism of patellar tendon rupture
Roberson’s patellar tendon rupture took place when he slipped while jumping. Here’s the moment it happened:
In that moment, the extensor mechanism of the leg (which includes the patellar tendon) is activating forcefully to straighten the knee and jump into the air. However, when Roberson slips, it takes his knee into a flexed (bent) position – resulting in the patellar tendon contracting against heavy resistance.
Think about it like this: You’re about to do an explosive dumbbell curl with a light weight (lets say 5 pounds) and as you’re about to intensely curl the arm up, an additional 50 pounds is added. You’re making a forceful contraction against a weight that you weren’t ready for or expecting – that’s a recipe for overloading the muscle and tearing fibers. That’s what happened to Roberson – in his case a complete rupture.
However, and this is why I brought up Roberson’s injury history, the stress on Andre’s patellar tendon isn’t nearly as much as Lin’s. For starters, take a look at the difference in the knee bend at the moment of injury:
Lin’s knee is more flexed than Roberson at the moment of injury. The greater the knee flexion, the greater the stress on the patellar tendon.
Additionally, Lin’s patellar tendon is being loaded with landing forces whereas Roberson’s patellar tendon is being loading with jumping forces. The former are significantly higher than the latter.
So even though Roberson had less stress on his patellar tendon, he still suffered the same injury as Lin. This tells me that Andre’s patellar tendon was less capable of handling stress (aka his injury risk was higher) and that makes sense based on his injury history – specifically the left knee patellar tendonitis he was battling weeks prior.
Now that we’ve looked at the specific mechanisms of injury for Lin and Roberson, let’s take a look at the symptoms….
IV. The symptoms of a patellar tendon rupture
The symptoms of a patellar tendon rupture can include the following:
- Inability to weight-bear or you can only do so with help
- Knee buckling or giving way when you try to walk
- An indentation at the bottom of your kneecap where the tendon tore
- Muscle cramping
- The patella (kneecap) displacing up into the thigh because it’s no longer anchored to your tibia (shinbone). Here’s an x-ray of what that looks like:
- Incomplete extensor function (can’t straighten the knee)
- Sometimes people can feel or hear a tearing or popping sensation, followed by pain and swelling. For example, Roberson said he “heard a pop” when the injury happened.
In the case of a full rupture, surgery is required…
V. Lin and Roberson’s Surgery
A patellar tendon rupture requires surgery to reattach the torn tendon – research shows that the earlier the surgery happens, the better the outcome. This is because an early repair, within 2 to 6 weeks, can prevent the tendon from tightening and scarring into a shortened position. Lin had surgery the day after and Roberson two days after his respective patellar tendon rupture.
If the diagnosis is delayed more than 6 weeks after the initial rupture, shortening of the quadriceps and fibrous adhesions can make it more difficult to complete the surgery and restore the length of the patellar tendon.
A. The Procedure
The first step of the surgery is to drill holes through the patella (kneecap), place sutures in the tendon, and then thread them through the holes. The sutures are then tied at the kneecap. Here’s what that looks like (work-safe):
At this point, it’s critical for the surgeon to carefully tie the sutures and get the correct tension in the tendon. This also ensures that the kneecap position closely matches where it was before the injury.
As an aside, there’s an emerging new technique where the kneecap doesn’t have to be drilled into. In this technique, the tendon is attached to the bone using small metal implants called suture anchors rather than being threaded through the drilled holes. It’s a relatively new technique so data collection and research is ongoing to assess its effectiveness.
B. Additional considerations
If the repair needs extra protection, some surgeons will use a wire, sutures, or cable to help hold the patella (kneecap) in position while the tendon heals. In these cases, the extra hardware may need to be removed at a later point. For example, Kyrie Irving – who didn’t have a patellar tendon tear but did have wires placed in his patella to repair a fracture – had his hardware removed because it was irritating his knee. I wrote specifically about Kyrie’s case here.
VI. Lin & Roberson’s recovery and rehab
A. General guidelines
After surgery, the involved leg is placed in a hinged knee brace that is locked in extension (to keep the leg straight and allow for appropriate healing of the patellar tendon) . The knee brace stays locked in position until you have adequate quad strength and can walk normally. Here’s one example of what that hinged knee brace looks like:
The general plan for rehab is to incrementally allow greater weight-bearing while gradually increasing range of motion.
Commonly around 12-16 weeks (3-4 months), the knee brace is removed, there are no weight-bearing restrictions, and you can start to work on higher level quadriceps strength and neuromuscular training – aka training the unconscious processes that help generate fast and optimal muscle firing patterns, increase dynamic joint stability, decrease joint forces, and aide in learning movement patterns and skills
After 16-24 weeks (4-6 months), you can usually return to running and sport specific training. Once the quad on the involved side is able to test 85-90% as strong as the uninvolved leg, you can return to jumping and contact sports – commonly around the 6 month mark, post surgery. However it can take up to a year+ for there to be minimal side to side deficits.
For reference, Roberson ruptured his patellar tendon about 3 months ago whereas Lin ruptured his nearly 6.5 months ago. Based on the general timelines, Roberson would just be getting back to full weight-bearing and starting to ramp up his rehab while Lin should already be back to dynamic and on-court activities.
Let’s check-in with each on their physical and mental journey back….
B. The physical recovery & rehab
As I outlined above, there’s a well established protocol for the recovery and rehabilitation of the patellar tendon. Roberson suffered his patellar tendon rupture months after Lin so he’s not nearly as far along in the process. Let’s start with Roberson:
1 – Roberson’s physical recovery
On Feb 12th (about 2 weeks after the patellar tendon rupture), Roberson was in the very early stages of rehab – focusing on exercises to prevent leg atrophy and stimulate his leg muscles. He still wasn’t cleared to travel with the team because air travel after surgery increases the risk of blood clots.
On March 7th, Roberson had his first media session and said:
“Can’t do much, just at the foundation stage. Slow bends, quad contractions to keep the muscle going, keep the blood flowing to avoid any blood clots, and walking, straight leg of course. Just trying to get back to the movement stages”
As you can tell, the physical rehab is very slow going in the early stages – focusing on slowly increasing range of motion, keeping the muscles active, and still keeping the knee straight during walking.
On April 23rd, this video was posted:
Andre Roberson Rehab Chronicles cont. pic.twitter.com/0pV6eihAgc
— Erik Horne (@ErikHorneOK) April 23, 2018
You may be wondering “what the heck is he doing?” Well, you’re in the right place to answer that question. There are 2 key reasons for this activity:
- Walking backwards promotes full extension (straightening) of the knee (just try it and you’ll see).
- Going down stairs backwards puts a resistive load on the patellar tendon as well. Whenever Roberson goes to step back and down with his right leg, his left knee has to bend in a controlled manner (eccentric control). This mimics a key functional role of the patellar tendon.
All in all, Andre is coming along well. The locked brace is off and he has progressed to the movement stages as he was hoping to. Considering it’s only been about 2 months since the injury, he still has a ways to go but provided there are no setbacks, I imagine he’ll be progressed to higher load strengthening soon.
Moving onto Jeremy:
2 – Lin’s physical recovery
Lin has taken a bit of a different and more holistic approach to his rehab.
On Nov 30th (days after the injury), he announced that he was going to spend most of the season at Fortius Sport & Health in Vancouver. Here’s what he said:
“The Nets and I have decided on a really comprehensive rehab program that will have me out here most of the season. The goal is to rebuild my body from the ground up, each and every muscle and joint, not just the patellar tendon. I can’t wait to get healthy and come back even stronger.”
On Feb 8th, Lin spoke in detail about this holistic and comprehensive approach:
“I’m not going to change the bread and butter of who I am which is downhill, attacking, dynamic playmaking. I’ll always be that player…What we’ll see is probably a similar style, but in a safer way. I’ll still be in the paint heavy, but I won’t be landing on my legs the same way, getting off-balance unless obviously I’m forced to. But the landing, taking contact, being able to engage certain muscles before contact, before I take off, all those things are really important.”
He expounded further:
“It’s not just the plays that make you go ‘ooh’ and ‘ahh’ and ‘ouch’ that hurts. It’s more everyday movement, like if I’m moving inefficiently or if I’m putting extra load on my right knee throughout the course of the game..that’s going to be a big area of improvement. A lot of other muscles will be absorbing impact that joints shouldn’t be.”
In a nutshell, he’s speaking on re-learning and changing his movement patterns and muscular sequencing (neuromuscular training) to reduce the amount of stress on his knee and re-distribute it across the body.
Let me illustrate with an example – Jeremy mentioned changing the way he lands. Changing landing patterns can be key in changing the amount of stress on the knee.
Take a look at this picture that compares an upright landing (a lot of knee bend, limited hip bend aka a knee dominant pattern) with an angled landing (less knee bend, more hip bend aka a hip dominant pattern):
The knee dominant pattern (picture on the left) puts a lot more stress on the knee whereas the hip dominant pattern (picture on the right ) puts more stress on the hip and takes it off the knee.
If you’re wondering “wouldn’t this just hurt the hip then?” – great question and the answer is no because the hip is able to handle a lot more load than the knee.
To re-train this pattern, Lin has to constantly work on breaking the upright knee pattern and “sinking back into” the hips when landing. If you’ve ever tried to learn or teach someone else to squat with their hips and not their knees, it’s basically the same principle (load the powerful posterior chain – the hamstrings, glutes, low back extensors – rather than less capable muscles)
On March 6th, we got some video of Jeremy shooting around:
Look who is putting in the work 👀 pic.twitter.com/flccdhzf1l
— Brooklyn Nets (@BrooklynNets) March 7, 2018
At this point, he was over 4 months removed from surgery so he was right around the point where you would normally get back to more dynamic sport-specific activities.
On March 8th, Jeremy gave an update:
“I feel really good. Still no setbacks, everything is going to plan – the time we set in the beginning. I really can’t complain, it’s been a lot smoother of a process than I anticipated.”
And finally, a few a weeks ago on April 16th, Lin gave a comprehensive review of his rehab and process:
“I’m looking at whether I have done enough to completely change pre-existing movement patterns…everything down to my shot, the way I run, the way I defend, the way I move. Cut, accelerate, decelerate, everything. It won’t look to the eye or on TV any different, but it will be very different in terms of how I do it and where I moved from and what muscles I’m using and what tendons and joints I’m not using.”
“I definitely learned more about science and anatomy than I ever thought I would. But I’m excited and I feel like I’m moving better and it’s going to help my game.”
“There’s principles that make a lot of sense intuitively – you want to move from your core, you want to reach, you want to push. You want to make sure that you’re sinking into your hips. You’re using your strongest muscles on your body. You’re using your quads and your glutes, not your knees basically, and things like that. There’s a lot of movement philosophy behind what I’ve been learning.”
Movement science is a lot of fun and with patience, dedication, and a willingness to change, you can learn and accomplish a lot by harnessing it effectively. Jeremy has embraced it and I’m excited to see the changes for next season.
All that being said, the physical recovery is only half the battle…
B. The mental recovery
The stark reality of injury rehab is that it’s not only about whether the tissue, in this case the patellar tendon, has healed or not. The concept of chronic pain and pain science revolves around the fact that you can still feel pain even after the tissue has been “medically cleared”. Kawhi Leonard is a pertinent example of that and I wrote about his saga here.
Therefore, the mental aspect of healing and recovery is, in my opinion, just as important as the physical component. Staying engaged and not reclusive while being in a positive, supportive environment can work wonders. Some benefits include:
- Reducing stress levels. Stress can increase pain sensitivity and overall systemic inflammation
- Mitigating negative thoughts and fixation. Studies have shown that fixation leads to the area in the brain responsible for that body part actually growing in size (termed “cortical re-organization”). This creates increased awareness and feedback of that area (like “shining a spotlight on it”) which leads to more pain…and more negative thoughts and fixation…and so on – a truly vicious cycle
- Increased resiliency and perspective to get through setbacks. We all need a helping hand once in awhile – a man on an island usually dies.
Fortunately, it seems that both Roberson and Lin have all of these components. Lets check-in…
1 – Roberson’s mental recovery
By all accounts, Roberson has stayed engaged with the team and helped out with preparation and mentorship.
Here’s what Steven Adams had to say on Feb 12th:
“He’s been around in the background…he’s around all the time. It’s good, mate. He’s just doing his own thing, a little rehab. It’s a tough situation to be in, but he’s still keeping in happy spirits, good spirits.”
This is Billy Donovan speaking on Andre’s involvement with the team:
“I do think where he can provide a lot of input is just scouting reports, preparation, those things…him being able to give insight to a Terrance Ferguson, to an Alex (Abrines), to guys that are gonna be in his position, Josh (Huestis), I think that’s become very impactful…the way he thinks is a lot different than any other player.”
Additionally, Roberson’s teammates and the Thunder organization and have been extremely supportive of him. Steven Adams speaking on it:
“It is a lonely thing because you see all the boys still working out and you’re just in the background…you can feel pretty (expletive), so yeah the Thunder do a really good job at kind of trying to help that.”
Coach Donovan on the benefits of camaraderie and being around the team:
“it’s healthy for him that he sees those guys. I think any time you’re going through an injury, it can kinda seem like a lonely existence, the things you’re doing by yourself and alone. So, I think the more he’s around his teammates, the organization, I think the better.”
On March 7th, Roberson addressed it as well:
“It’s definitely tough but I’m doing everything I can to stay involved (with the team). Being around the guys just makes me feel not alone”.
As Roberson alluded to, rehab can be a lonely place. In the sports world, it’s a lot of 1 on 1 with the same person for multiple hours on end and you can’t be on the floor with your teammates. However, being around the team allows for Roberson to re-gain that sense of camaraderie, team, resiliency, and give him more perspective on what he’s fighting hard to get back to.
This sense of perspective and resiliency characterizes Roberson’s approach:
“What I’m all about is accepting and taking on challenges”.
That mentality is so critical (and I cannot stress that enough) when it comes to injuries, especially major ones that involve extended rehab.
The last thing I’ll touch on with Roberson’s mental state is his extremely close friendship with Steven Adams. The reason why Adams has so many quotes regarding Roberson and his recovery is because they are best friends. Here’s how Andre described their friendship:
“my buddy since day one…we’ve been through a lot together and this is just another thing we’ll get through”
The quote alone says it all but also notice how Andre refers to himself and Adams collectively as “we”. That’s truly a brotherhood relationship right there.
Think about those times where you may have been struggling and you relied on that one friend or group of friends to help pull you through. It’s huge for mental recovery and Roberson clearly has that type of friend in Steven Adams.
2 – Lin’s mental recovery
Lin, like Roberson, has also stayed highly engaged and interacting with the team. Here’s Kenny Atkinson on Feb 8th talking about it:
“He (Lin) is one of my text buddies. He sent me a pick-and-roll defense, it was like a Harvard NBA presentation on pick-and-roll defense and how to become a better pick-and-roll defender. It’s like, ‘OK, Coach Lin.’”
“He’s so involved. He’s not just sitting there doing his own thing, he’s always hitting me with stuff after the game.‘You could’ve done this, you could’ve done that’, it’s great. And I know our medical team is all over him. He’s in a really good place, he’s happy with how he’s progressing.”
Jeremy, on March 8th, talking in detail about the team’s recent games and trajectory:
“We just have to close out games. It’s coming down to a couple of plays at the end [sighs]. It just comes down to a couple of details. Guys have talked about it — the coaching staff is working hard at it and the players are trying to make it work. We should be able to pull out a couple of close wins in the next week or two.”
“I think guys are also understanding like ‘Dude, we’re right there.’ There’s a saying in the NBA, ‘Don’t get too high, don’t get too low.’ I think we’re kind of figuring that out right now. Let’s just stay even-keeled and stick with the gameplan – you never know when that breakthrough is going to come…I think that’s what everyone is working on.
It’s clear how involved and invested Lin is in the team’s game to game play, and he keeps himself mentally engaged by trying to help.
Additionally, Lin’s rehab team in Vancouver have been in constant communication with the Nets about Jeremy’s progress. This provides piece of mind and confidence in the process and in both organizations. Jeremy touched on it:
“That’s been the thing that I’ve been absolutely blown away with…how much they’re communicating and every little thing gets passed on to every single person down the line, and everyone in Brooklyn knows, and everyone in Vancouver knows every little thing that happens, every milestone that we pass or whatever it is.”
Further, and Jeremy has been very transparent and forthcoming with this which is why I bring it up specifically for him, Lin’s family support has been tremendous and critical for his mental recovery.
He’s extremely close with his family and has a very tight family unit that he relies on. The following video does a great job of showing that relationship and connectivity:
Two great quotes:
“I wouldn’t be here without them. In the times I couldn’t find the strength to even show up to my next game, or even show up to my next practice, my family would come and visit and be there for me. They’v always believed in me and in due time I’ll overcome the obstacle in front of me”
“Pretty much every athlete will go through moments of self-doubt – I definitely had and will continue to battle certain thoughts or feelings – and my family has always stuck by my side”
Lastly, and Jeremy touched on this directly in that video, the support from the fans has been incredible. Here’s a quote:
“The most impressive thing is not just the fact that fans have gone online to send really warm things, like messages and encouraging notes, it’s the solidarity and unification of fans…it’s been amazing”
Knowing that so many people are behind you and want you to get back to 100% must feel incredibly empowering, uplifting, and motivating.
Both guys seem to be well on their way physically and mentally, but let’s take a look at if they face any long-term consequences after a patellar tendon rupture.
VII. Long-term implications of patellar tendon rupture
In some cases, and not infrequently at that, there is a sustained loss of quadriceps strength and loss of full knee flexion. Additionally, there is the chance of re-rupture (I couldn’t find the overall rate) but it’s usually in individuals who return to athletic activities too quickly, before the tendon is healed.
However, overall patellar tendon rupture repair has a good prognosis when diagnosis and surgical treatment is performed quickly, and an early rehabilitation program is implemented. Lin and Roberson both meet these criteria.
VIII. All in All
All in all, a patellar tendon rupture definitely sucks because it’s a long and arduous road to recovery. However, based on all the indicators that I’ve seen and found, it looks like both Lin and Roberson are meeting their physical milestones, are in a good spot mentally, and are surrounded by supportive organizations, teammates, friends, family, and fans.
Thanks for reading and until next time.
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