Welcome back for another installment of Research Bites! For all of you who missed my research posts on my Instagram (@science_of_falling), you came to the right place. Every few weeks I will be posting a new set of five quick and dirty research reviews with the main findings, how it was performed, and my quick take on it.

The trick is, I only have the space of an Instagram caption (2200 characters) to dive in and extract main points. It makes for a fun challenge! If you want to see these posts sooner, head on over to Instagram and hit that follow button.

Enjoy that tasty research!

Study Details

🔸28 participants
-14 with DPN, and 14 healthy controls
-Matched for age, gender, BMI
-All participants ~73 yo +/- 4 years
🔸DPN determined by utililizing the Diabetic Neuropathy Examination (DNE)
-Scoring: 0-16 points; score 3> = DPN
🔸All participants underwent a functional balance evaluation utilizing the Berg Balance Scale (BBS)
-Consists of 14 functional tests which imitate positions used in ADLs
-Scoring: of 0-56 points; higher scores = better balance
-Each functional test performed 3x with highest score being recorded
-Functional test scores tallied for total BBS score

Study Findings

🔹BBS combined scores (all scores in one group combined) significantly different between groups (DPN 105 vs Control 301)
-Significant reduction in balance ability for the DPN group compared to control group
🔹Significantly lower scores for DPN group in one leg standing, unsupported one foot in front, reaching forward with out stretched arm, unsupported feet together, sitting to stand, standing to sit, transfers, stand with eyes closed, alternating foot taps on stool
🔹Strong negative correlation between DNE and BBS score
-Higher levels of neuropathy = lower balance performance on the BBS

My Take 🤓

This study's findings may be obvious to many in the healthcare field, but not necessarily to the general public. Neuropathy is a huge factor in balance that cannot be seen visually and many don't even know it exists. The somatosensory system is such a large part of balance, and if disrupted, clearly affects functional balance to a large degree.

Study Details

🔸9 Korean national snowboarders (6 male, 3 female); Age 17.44 +/- 4.42; Career years 6.67 +/- 3.12; all regular stance riders (L foot forward)
🔸Participated in study during the off-season
🔸Physique parameters measured: fat mass, body fat %, BMI, muscle mass index
🔸Length and circumference of thighs (L&R), biceps (L&R), legs (L&R), chest, and waist recorded
🔸Physical fitness parameters measured: bilateral ankle flexibility (dorsiflexion & plantarflexion), # of sit ups in 60s, bench press max, squat max, isokinetic maximum strength ratio (flexion/extension) of bilateral knee joints at 60 deg, bilateral knee joint stability, 1-leg standing time in seconds, L/R/center dynamic balance (measured on stability platform)

Study Findings

🔹Static balance seemed to be positively correlated to the circumference of the L lower leg, sit-up ability, bench-press, L-ankle dorsiflexion, L knee avg power isokinetic extension at 180 deg, and R knee isokinetic peak muscle flexion strength at 60 deg

My Take 🤔

This study was done on only 9 snowboard athletes in Korea, and therefore should be taken with a grain of salt until further studies are performed.

That being said, regular riders depend on their L leg (front leg) for stability and strength to maintain balance while snowboarding. Additionally, having a strong trunk (chest and stomach) allows for increased stability and force transfer through the legs.

Consequently, the study's findings make sense. Circumference of muscle, and max lifting tests, are all good indicators of muscle ability. If the front thigh is bigger, it stands to reason more muscle is present and therefore the potential ability to stabilize is higher. Higher max lifts also allude to this. Ankle DF has been shown in previous studies to increase static balance ability too.

Study Details

🔸21 experimental subjects (16 females, 5 males; ages 67 +/- 4 years)
🔸12 control subjects (5 females, 7 males; 68 +/- 3 years)
🔸Both groups underwent forward fall testing via a simulated forward fall protocol created during a previous study by Karamanidis and Arampatzis in 2007
-Intention of fall protocol was to test the subjects ability to catch self with a single step when falling forward
-subject attached to harness and leaned forward until 8-10% of body weight (BW) tension into harness; lean amount measured in cm
-dropped at random intervals and tested to see if they could recover from fall with single step
-If successful BW % in harness increased by 2-3% and repeated
-Addition of BW into harness (and resulting forward lean angle) stopped if subject was not able to recover fall in one step
🔸Utilized force plate and motion capture system to collect data
🔸Experimental group underwent maximal isometric voluntary contractions (MIVC) of the ankle plantar flexion and knee extension performed on a dynamometer
🔸After testing, experimental subjects underwent 14 weeks, 2x/ week, 90 minute sessions of mini-trampoline training

Study Findings

🔹No increase in knee extensor MIVC pre/post, but ankle plantar flexor MIVC ⬆️significantly from 141.9 +/- 28.2 Nm -> 155 +/- 32.5 Nm
🔹Experimental subjects showed 35% ⬆️ ability to recover balance after falls from ⬆️ inclines (more BW into harness)
-Pretest incline 14.1 +/- 4.3cm, post incline 19.1+/- 5.1cm
🔹Experimental group showed ⬆️ hip joint moment generation at fall release leading to faster recovery step during post testing.
-Pre-test 225ms +/- 37ms vs post-test 195 +/- 35ms
🔹Control group did not change significantly on any testing

My Take 🤔

What this study really boils down to is that mini-trampoline training may increase muscular power production in the lower body. This increase in power (strength x speed) can result in a faster leg and hip drive upwards resulting in an easier time stepping out during a forward fall.

Study Details

🔸25 female softball players, 15 female control cross country runners; 18-25 yo; all competing in NCAA (Division I-III)
🔸Softball players chosen due to the chronic asymmetrical loading nature of their sport, while cross country runners demonstrate a more even loading of the lower body
🔸Compared bilateral proximal femur properties
-Whole Body DXA scan
-Bilateral imaging with CT scan
🔸Proximal femur volumetric bone density, bone mineral content, and volume computed from data
🔸Used Finite Element (FE) Modeling to estimate proximal femur strength when under load in single leg stance, as well as during a fall sideways onto the greater trochanter

Study Findings

🔹Softball pitchers showed significant differences between dominant and non-dominant proximal femur, femoral neck, and trocahnteric volumetric bone mineral density and content; as well as in femoral neck volume
-Increased significantly in dominant leg
🔹FE modeling showed 19.4% increase of femoral bone strength in the dominant leg during single leg stance
🔹FE modeling showed 4.9% increase of femoral bone strength in the dominant leg during sideways fall and load of the greater trochanter
🔹No significant differences shown in cross country runner's femoral data

My Take 🤔

This is an interesting study overall. Wolff's Law states that bone will adapt in the direction and to the degree of load under which it is placed. Female softball players show increased bone strength by almost 20% in single leg stance positions. This makes sense due to the vertical loading placed created as they step forward during a pitch.

They were also shown to have almost 5% increased strength in a lateral direction which can help reduce chance of injury during a sideways fall. Because these athletes are not directly loading in a lateral direction these findings are interesting. This increase in bone strength may be due to angle of the forward step, or natural hip geometry.

Study Details

🔸47 older adults (mean age 74.8 +/-7.1); 13 males, 34 females
🔸Underwent motor assessment and general cognition screening via: Berg Balance Scale, Timed Up and Go, handgrip strength in kg, Montreal Cognitive Assessment, Trail Masking Test-B, Movement Specific Reinvestment Scale, and the Falls Efficacy Scale-International
🔸Completed 60s narrow stance balance trials on force platform
🔸Completed a single 60s trial under two conditions: high CMP, low CMP
-CMP is defined as how much mental effort is used to think about the movement task at hand
-During high CMP trial the participant would hear a beep indicating them to think and verbally express where their weight was distributed, and how it had changed over the last 10s
-Beep could happen any time per instructions to participants, but the beep always came on AFTER the 60s data collection process for the trial
-In the low CMP trial participants focused themselves on an unrelated task (reciting months of year repeatedly) during the 60s trial period to distract their attention from the balance task

Study Findings

🔹CMP had no significant effect on overall sway amplitude
🔹Balance capacity significantly correlated positively with mediolateral sway amplitude in the high-CMP condition, but not in the low-CMP condition
-Higher baseline balance ability = more sway during conscious focus on balance task
-Balance capacity did not affect sway amplitude in distracted trials, and had no influence on anterior-posterior sway
🔹Significant effects in sway frequency during mediolateral and anterior-posterior directions noted with CMP manipulation
-significantly lower in both directions in high-CMP compared to low-CMP
🔹Complexity of mediolateral balance significantly lower during high-CMP and higher during low-CMP

My Take 🤔

Older adults with better balance are more negatively affected during conscious balance efforts especially in the mediolateral direction. This may be due to previously trained automatic processes being disrupted. I would compare this to your normal walking cycle. When you automatically walk, as your body has been trained to do, you are fluid and natural. The minute you start thinking about how to walk it can become awkward and clunky. Our brain has evolved to streamline certain processes to free up mental space. Consciously thinking about these processes disrupts the streamlined flow, and therefore slows down the entire bodily operation at hand.

Thanks for reading the eighth volume of Research Bites! I hope you learned a tidbit or two. Be sure to follow my Instagram account to see these research bites right away, and comment below on what you think about the findings above.

Happy Falling!