Tag: recovery

Slipping or Tripping? Researchers Find Best Way to Regain Your Balance

Everyone has slipped or tripped at some point in their lives. Whether it is walking on an icy road to get to your car or tripping over the Lego set your kid refused to put away, everyday obstacles can cause us to lose our balance. Often this results in a brief moment of panic followed by the uneasy relief of regaining your footing, but for those who aren’t lucky enough to avoid falling, the results can be devastating. This is especially prevalent in populations more susceptible to falling. Falling in the workplace accounts for 16.8% of all non-fatal injuries leading to days taken off work. It is thought that this is due to the high volume of slipping or tripping obstacles encountered in some occupations. Additionally, 36 million falls resulting in 32,000 deaths were reported for the 65+ year old population of the US (Bruijn et. al 2022). Elderly individuals may lack the strength and reflexes necessary to recover their balance quickly. This is especially worrisome because the elderly are also the most at risk for the major health complications that can be caused by fall related injuries.

While it may not always be possible to avoid the obstacles that cause us to slip or trip, it may be possible to decrease your likelihood of falling as a result. Biomechanics researchers Daniel Marigold, Sjoerd Bruijn, and Rakié Cham attempt to determine what human responses allow us to recover our balance after slipping or tripping. To do this, these researchers subjected volunteers to a slip or trip course where they would be caused to periodically slip or trip. When the subject slipped or tripped, the researchers would use a special camera to map out the subject’s movements throughout the response and sensors placed on the subject and course to determine the muscles and forces acting throughout. As a result, the researchers were able to find various patterns that may explain how some subjects were better able to recover their balance.

Example Testing Course Diagram Showing Cameras and Sensors (Marigold 2003)

When discussing slip and trip responses, researchers distinguish between a subject’s legs by defining the leg that first encounters the slippery surface or hits the tripping obstacle as the “perturbed limb.” On the other hand, the leg that does not encounter the obstacle first is called the “unperturbed limb.” 

Though each researcher devoted their attention to a different limb response, there were similar patterns seen throughout all of the research. Firstly, it was found that the unperturbed limb is used within slipping or tripping primarily to catch the body. For example, under slipping, the unperturbed limb would help catch the body by touching the ground briefly near the perturbed limb before taking its subsequent step. Similarly, when tripping on an obstacle, the unperturbed limb would step over the obstacle to catch the subject. Additionally, it was found that subjects were able to recover better when their arms were extended as opposed to abruptly brought into the body. Researchers struggled to come to a consensus on why this is the case, but Marigold believed this was the body’s way of balancing its offset mass (like when someone extends their arms while walking on a balance beam). On the other hand, Bruijn thought that it was important to keep one’s arms extended and moving to delay the transfer of their momentum (arm mass movement) to the rest of the body, like when a spinning figure skater keeps their arms extended to spin slowly. Finally, it was found that the perturbed limb responded by attempting to pull back towards the neutral standing position. When you slip, your perturbed limb tends to slide forward and away from your body, so in response, the muscles in this limb try to pull it backwards and towards your body.

So your body responds by catching itself with the unperturbed limb, extending your arms, and pulling the perturbed limb closer to your body, but what makes some people more successful at this than others? Researchers emphasize acting quickly but not abruptly. Though reaction time is important, subjects who panicked would rush the stabilizing step with their unperturbed limb, pull their arms in suddenly, and pull their perturbed limb inwards too harshly. It seems that the best thing to do when slipping or tripping is to remain calm and allow your body to react at its own measured pace.


Bruijn, Sjoerd M., et al. “Contribution of Arm Movements to Balance Recovery after Tripping in Older Adults.” Journal of Biomechanics, vol. 133, Mar. 2022, p. 110981. ScienceDirect, https://doi.org/10.1016/j.jbiomech.2022.110981.

Cham, Rakié, and Mark S. Redfern. “Lower Extremity Corrective Reactions to Slip Events.” Journal of Biomechanics, vol. 34, no. 11, Nov. 2001, pp. 1439–45. ScienceDirect, https://doi.org/10.1016/S0021-9290(01)00116-6.

Marigold, Daniel S., et al. “Role of the Unperturbed Limb and Arms in the Reactive Recovery Response to an Unexpected Slip During Locomotion.” Journal of Neurophysiology, vol. 89, no. 4, Apr. 2003, pp. 1727–37. journals.physiology.org (Atypon), https://doi.org/10.1152/jn.00683.2002.

Slip, Trip, and Fall Prevention – Tokio Marine America – Property and Casualty Insurance Provider. https://tmamerica.com/insights/blog/Loss-Control-Slip-Trip-Fall.aspx. Accessed 4 May 2022.

Stein, Jeff. “Man Slipping.” Pixabay, 23 Jan. 2020, https://pixabay.com/vectors/man-slipping-4785896/. —. “Man Tripping on Debris.” Pixabay, 23 Jan. 2020, https://pixabay.com/vectors/man-tripping-on-debris-4785967/.

The Ultimate 2-for-1: the Power of Contralateral Strength Training

For the competitive athlete, injury often means loss. Loss of playing time, loss of skill development, and most importantly, loss of training time. These are all unfortunate consequence of getting a bone or tissue injury requiring a long-term healing prognosis. Injuries can be so devastating because the road to recovery is often times an arduous two-step process. First, the athlete must wait for their broken bones, torn ligaments, or pulled muscles to naturally heal. During this time, the athlete’s injured limb is likely immobilized in a cast or brace, leaving the resulting muscle to slowly atrophy as the body tries to heal itself. As a result, an athlete must spend the second part of their recovery process re-training the weakened muscles in the immobilized limb to return to full-strength. What if there was a way to heal and train the body at the same time? This is the power of a neurophysiological phenomenon known as “contralateral strength training.”

First observed in 1894, this phenomenon describes the increase in strength seen in an untrained limb of the body after strength training the opposite limb. For example, performing strength training exercises using the left arm has been shown to also induce an increase in strength in the right arm without working out the right arm at all. This effect can be seen in all different muscle groups in the body, in both males and females, and in people of all different ages. Researchers have hypothesized that high-force contractions used in resistance strength training can have a “spillover” effect on the neurons controlling the opposite limb. These neural circuits can carry motor output signals from the trained muscle to the untrained contralateral muscles which works to increase the electrical activity of the untrained muscle and effectively activate the muscle as if it were being trained as well. The video from the YouTube channel “House of Hypertrophy” helps illustrate this effect.

This video is from the YouTube channel “House of Hypertrophy” and helps illustrate the contralateral strength training phenomenon.

Harnessing the power of this neurophysiological phenomenon is key to injury recovery especially when one limb is immobilized for an extended period of time. It’s not just for competitive athletes either. Anybody with an injury can take advantage of contralateral strength training to dramatically speed up injury recovery. This can be especially useful for the elderly population where maintaining balance is an important factor of injury rehab. Imagine being able to maintain the strength and mobility of an elderly patient’s leg after a common surgery such as a knee replacement. Although the leg will be immobilized by a brace or a cast to keep the knee stable after surgery, it could be possible to prevent the muscles from atrophying by simply training the opposite leg with effective physical therapies. This could mean the difference between a smooth recovery versus one where the patient faces serious balance and stability issues as a result of a weakened limb that was immobilized in a cast for weeks to months at a time. Whether it be for injury recovery or specialized strength training, contralateral strength training has an amazing 2-for-1 effect in which the body’s own neural mechanisms allows both homologous muscles to experience the effect of a single unilateral training.

Ankle Sprains: An Epidemic in the World of Athletics

Have you ever been out running on a gorgeous fall day, only to have the run cut short by a painful misstep on a tree root covered by leaves? I have, and let me tell you – it’s awful! And even if you aren’t a runner, according to the Sports Medicine Research Manual, ankle sprains are a common, if not the most common, injury for sports involving lower body movements. Now, the solution to preventing this painful and annoying injury could be as simple as avoiding tree roots and uneven ground, but the real problem behind ankle sprains deals with the anatomy of the ankle.

The ankle is made up of many ligaments, bones, and muscles. However, when sprained, it is the ligaments that are mainly affected. Connecting bone to bone, ligaments are used to support and stabilize joints to prevent overextensions and other injuries. The weaker a ligament is, the easier it is to injure. There are three main lateral (outer) ligaments supporting the ankle joint that can become problematic: the anterior talofibular ligament, the calcaneofibular ligament and the posterior talofibular ligament. According to a study from Physiopedia, these lateral ligaments are weaker than those on the interior (medial) of the ankle, with the anterior talofibular ligament being the weakest.

An image depicting the various ligaments of the ankle, both lateral and medial.
Anatomy of the ankle, highlighting the lateral and medial ligaments

The next question that has to be asked is why are these ligaments so much weaker than other ones? The answer to this question is based on their physical make up. Ligaments are made of soft tissue that has various collagen fibers running parallel to each other throughout it. The more fibers there are, the more structure and rigidity there is. Think of the fibers as a rope: The rope can stretch to a certain point, but once it hits that point it will snap and break. But if you have a thicker rope (such as the medial ligaments), it becomes much harder to break.

The ligaments on the outer part of the ankle have fewer collagen fibers than those on the inside of the ankle. Thus, when the ankle is moved in an awkward position, it is more likely that the lateral ligaments will break.

Once you sprain your ankle, the focus turns to treatment. Treatment will differ slightly for every individual depending on the severity of the ankle sprain. The simplest way to treat a sprained ankle is to follow the RICE (Rest, Ice, Compression, Elevation) method. Other forms of treatment include taping the ankle or using a brace to restrict movement and to add support and extra stability. Wearing proper footwear is another way that one can prevent and help treat a sprained ankle, as certain shoes are specifically designed to help avoid such injuries. To prevent future ankle sprains, exercises are recommended to help strengthen and stabilize the joint and surrounding ligaments and muscles.

For more information on ankle anatomy and sprains, check out these articles on BOFAS and SPORTS-Health.

Tearing and repairing the meniscus

How does someone go from being the youngest NBA MVP one year to barely making headlines the next? Ask Derrick Rose. After being named the youngest MVP in the NBA, Derrick Rose tears his ACL the next year and then tears his right meniscus twice in the span of three years. Knee injuries have not been kind to Derick Rose, but how does one tear their meniscus and how does it get repaired?

The meniscus is shown in Figure 1.

Showcases the location of the meniscus in the knee. Gives the user an image of how the meniscus works, and where it is located.
Figure 1

According to Sports Health, the meniscus is a type of cartilage that provides cushioning between the bones in the knee. The meniscus main role is to absorb shock and the impact on the leg and knee when it is in motion. It allows for stability and smooth motion between the joints.

In a game of basketball, one of the biggest sports in the United States, there is plenty of running, jumping to shoot the ball into the basket, jumping up to catch a rebound, and doing sharp cuts during the game to shake off a defender. All these movements cause high loading on the knee, and if there is an over-rotation on the knee during these movements, then it can cause a tear in the meniscus. The video below shows when Derrick Rose tore his meniscus.

In the video, it shows Derrick Rose doing a relatively easy movement, he plants his foot in order to change direction to chase after the ball. It is a non-contact movement, but due to an awkward landing on his foot, he gets injured and misses games for the rest of the season.

When the meniscus is torn, there are two options in terms of healing the tear. The options are getting the meniscus removed or getting it repaired. Both options have their own recovery time. If you get the meniscus removed, then the recovery time would be from four to six weeks. However, there are setbacks to getting the meniscus removed such as leading to early arthritis. If the meniscus is repaired, then the timetable to return to play is around six months. According to USA Today , he chose to get the meniscus repaired in order to not have future complications around his knee, which is why he had to sit out for the rest of the season. Going this route also gave Derrick Rose the chance to return to his playing form before injury. According to Stein, 96.2% of athletes that undergo meniscal repair go to pre-injury level of activity after the repair, which is good news for Derick Rose.

However, Derrick Rose tore his meniscus again the following season in 2015. He would then have surgery to remove the damaged part of the meniscus and would return in a couple of weeks. This would then be his third surgery to repair his knee, and his surgeries must have an effect on his playing performance. After these surgeries, the world waits to see if Derrick Rose can reach MVP status again during his career. It would be tragic to see that these knee injuries would ruin someone’s career.

Sources and Additional readings:

General information about the meniscus

Meniscal Injuries in the NBA

Injuries in the WNBA