Search the Community

Peak Performance Physical Therapy & Sports Training EVIDENCE-BASED PRACTICE UPDATE November 2023 The Effects of Power Training Frequency on Muscle Power and Functional Performance in Older Women: A Randomized Controlled Trial by Karen Napierala MS, AT, PT, CAFS What would you do? A 72 year old woman comes to PT with a history of falling over the past year. Her primary CC is a painful R knee along with lumbar DJD symptoms also. She underwent L THR three years prior and reports good function without hip pain. She wants to play in the yard with her grandchildren, who are under 10 yrs old, but feels unsure of her footing on the grass and at times is apprehensive due to occurrences of a “step in the wrong direction” causing sudden knee pain and associated giving way. Plain films show > moderate DJD of her R knee. R knee AROM is 5-1150, single leg squat is moderately decreased vs L, and SLB control is minimally reduced with static testing. I would prescribe… A. “RICE”, NSAIDs, and gradual activity return as able over 2-4 wks - call if problems persist. B. Obtain a knee MRI and lumbar plain films. Prescribe NSAID’s and recommend Physical Therapy (providing a geographic based list of options). C. Customized biomechanical PT to include Class IV laser, manual therapy, customized exercise/balance training progressing to include “speed/power” training - FU 6 wks. CURRENT EVIDENCE The Effects of Power Training Frequency on Muscle Power and Functional Performance in Older Women: A Randomized Controlled Trial, Katsoulis, Konstantina; Amara, Catherine Et al., Journal of Strength and Conditioning Research 37(11): p 2289-2297, November 2023. *** We are modifying the Newsletter format to better match our physicians’ time constraints. The previously more in-depth “Peak Perspective” will now be contained below in more “summary” form. We invite you to reach out to us at PT@peakptrochester.com or call our office at 585-218-0240 to further discuss this article in further detail if you wish. The abstract can be found after the case study. PEAK PERSPECTIVE & SUMMARY Physicians frequently see older patients with orthopedic conditions causing movement limitations, ranging from difficulty with simple ADL (such as walking and sit-stand or stairs) all the way up to higher demand athletic endeavors. While the worst of these cases involve actual falling and fall risks, a majority of older patients will complain of loss of quicker movement ability, reduced pace of activity, excessive perceived exertion with low demand activity, and also reduced ability to react to losses of balance…etc. Traditional physical therapy, despite its focus on typical ROM/flexibility, balance, and strength training, often neglects purposeful speed of movement focus (i.e., power). Physicians prescribing physical therapy must determine best practices for expectations and prescription habits surrounding these less customary but critical speed of motion components related to the patient’s goals and also determine appropriate DC criteria. Buford et al (2010) showed we lose 3-8% of muscle mass/yr as we age. Postmenopausal women lose more muscle mass per pound of body weight than men during aging, which is proportionally fast > slow twitch fibers (Fontera, et al 2000 Cell Physiology; Purves et al). This is consistent with the fall risk concerns of aging, where a component includes rapid deceleration capacity and acceleration qualities. Strength is important but inadequate itself in securing the capacity for rapid force generation. Muscle power training tends to be underutilized in physical therapy care but must be considered as part of a standard rehab progression if function is to be optimized. Low intensity power training has been used as an effective method to improve power and functional performance in these older adults in the gym, but it is underutilized in Physical Therapy. The RCT by Katsoulis and Amara studied the frequency of power training (1, 2 or 3 days per week) for 12 weeks on various power and strength measures in older women. Their “power” exercises focused solely on the concentric power in sagittal plane dominant exercise movements. Measures included 1 RM leg press, isokinetic knee extension, stair climbing , sit stands in 30 seconds and 400 m walk among several others. Functional tests such as leg press, sit stand, 4 m walk improved in the power training (PT) groups with 1-3 sessions/wk anywhere from 6-12%. Leg press 1 RM increased 23% pre to post. Rate of perceived exertion (RPE) for the 400 M walk was significantly improved over the controls in all groups. The BIW trained women improved in the stair climb test over the 12 week period. Chair sits to stand improved 10-19% in all PT groups. An 11-13 % improvement was seen in the 4 M walk. While significant power changes in 1, 2, and 3 times/week training groups were noted for isokinetic knee extension, the 3/wk power training group had four times more gains. This type of resistance training with quick motion and lower weight is crucial for functional results. Not only does weight training enhance muscle function, but the power or quick motion enhances fast twitch fibers necessary for reactive movements and power movements of getting up from the ground unassisted and climbing stairs, or even chasing grandchildren. While this study was done on otherwise healthy > 65 yr old females and external validity prevents us from directly applying the results in orthopedic patients we can still use this data to help frame important considerations for this population. Our patients are dealing with one or more painful joints that need to be addressed before moving into more progressive balance/strengthening and functional exercise activities intended to truly move the needle toward safer and higher function. We know that true strength takes at least 6 weeks to see results but changes related to the efficiency of the nervous system are occurring in the first weeks of training. Unfortunately, especially in this era of efficiency of care and early independence efforts and cost containment we often see patients following up with their physicians at a six week checkup who “feel better” but who still have significant disparities in strength and function still present, yet are oftentimes discharged from formal care to “keep doing your home program on your own” sort of thinking. Optimizing pace of movement and reactive ability, both for safety and performance/quality of life, are best done using speed based exercise movement drills vs simply traditional load based drills. Nevertheless, adequate strength must be developed first. Patients often are happy with the changes they’ve noticed already without appreciating the limitations their lack of speed capacity for deceleration/acceleration and perceived exertion are going to have. We utilize a “speed day” akin to this study’s intentions, however, importantly include or even focus on eccentric/deceleration based stimuli instead of just concentric power production. This is a known key to injury prevention. This often looks like 50% loads of their typical 8-12 reps training loads on a “strength” day workout but done with faster pacing usually over a short time of 10-20 seconds. Since many limitations and injuries come from the inability to control the forces of gravity while slowing down the body in motion, stopping, or especially reactively catching oneself after a slip or trip the eccentric “power” component is critical. This is often ignored in traditional therapy and as a requirement by physicians prior to discharge. Another key shortcoming in this study was the sagittal plane only training. In real-world function the frontal and transverse planes must be developed both in a dynamic stabilization sense during more frequent sagittal plane activities but also through motion also for activities like tennis, golf, and playing with grandchildren as even a few examples. The case below illustrates a patient who benefited greatly from incorporating this “speed day” training to optimize their recovery toward safer and higher level performance. THE PEAK PERFORMANCE EXPERIENCE Jody said: “I finally feel comfortable on the grass, and in the woods. I’m moving faster and my husband doesn't have to wait for me!” History: Jody is 84 and has (B) THA and a L TKA. She remained sluggish in her movement following her h/o DJD and the replacements but was also concerned about her “good” R knee’s progressive symptoms with stair. She struggled to get down on the ground to clean and needed a chair to help her up. Subjective: “I never felt like I fully got back to my activities. It took me much longer to get my housework done. I really want to take a walk on a path with my husband and keep up with the grandkids!” Objective: (*=pain) Initial Eval Re-Eval 6 wks Re eval 12 wks Sit -Stand 15 seconds 6x 7x 9 x Single leg squat knee angle L 550/ R 50 ** L 650/R 550 L75/R 67 Calf raise in 15 sec L 10/R 8 L 13 / R 10 L/R 16 3” quad dom step down (eccentric ) Unable * L 8x / R 7x L 16/ 14 TUG 20’ 16 sec 14 sec 12 sec Timed SLB rotations 15 sec Unable L 12x R 9x L 13x R 10x IKDC 32% 54% 79% Key Findings: Jody had 50 degrees knee flexion in a squat with pain at her patellofemoral joint. Split squat depth was 8 inches off the floor L forward. She had difficulty controlling ER’s on the R>L hip, and her R.L quad were weak. Calf weakness, especially soleus, was evident on the R side. Her balance was poor B in a single leg stance where she was unable to stand for more than 1-2 seconds at a time. Treatment: Jody has been in PT at Peak PT before and after each of her total hip surgeries. She has always been discharged after 6 -8 weeks of PT because she “felt better” and seemed capable of basic ADL. She is now realizing her “better” was actually not as strong as she needed to be and that she lacked the ability to move more quickly playing with her grandkids, carry loads down stairs, or hike on uneven terrain comfortably. After 3 weeks of lower level modified quads work (to avoid sx noted with a more flexed knee) Jody increased to resistive training into squats/ lunges/ and rotational/frontal plane assisted motion ensuring use of knee, ankle and hip muscles. By 6 weeks she was able to begin her light locomotion based agility program and also a “speed day” utilizing 50% of her typical loads for faster reps over 3 x 15 sec sets. The depth or ROM were adjusted as needed to optimize pace, maintain excellent technique and avoid symptoms. Keeping in line with this study's results she incorporated “speed/agility” day no more than 1-2/ week sandwiched in between her strength days. Outcome: Jody was doing well with only strength work but the addition of power and speed took her to the next functional level. She was finally able to move faster, feeling more secure and without falling. This is the best she has performed and felt in the past three years. ABSTRACT Background: It is known that muscle mass and strength decline with age but studies also show that power or dynamic strength capacities also decrease disproportionately for women vs men. Power training, where the load is substantial but significantly lighter than traditional strength training intensities, and the concentric phase is quick, is a form of exercise that is not frequently used in the older population but has been shown effective in improving muscle power and functional performance in older adults. Older adults often also feel more comfortable and willing to exercise with lighter loads. Purpose: To determine the efficacy of a low intensity (i.e. load), high speed exercise program done 1, 2, or 3 d/wk on lower body power and total body functional performance indicators. Type: Noninferiority RCT Methods: Fifty four healthy independent, active women over 70 yr of age were randomized into 1,2, or 3 d/wk of Power Training (PT) or the control group (CON) for 12 weeks. There were three testing sessions - baseline, midpoint, and 12 weeks as the dependent variables. Subjects were given four sessions of sub-max testing to prepare for the maximal effort tests. Measures included: Biodex maximal knee extension isokinetic test, leg press 1 RM, 30 second chair sit-stand , stair climbing power and timed 13 step stair climbing, 400 m walk, and a short physical performance battery (balance, 4m usual pace walk, 5 chair sit-stands). Findings: No differences were found between 1, 2, and 3 d/wk training frequency groups in leg press 1 RM, isokinetic knee extension power, or functional performance after 12 weeks. Leg press 1 RM increased 20-33% across all PT groups. Isokinetic power increased by 10% for 2 d/wk and 12% for 3 d/wk PT groups. All PT groups showed significant improvements in 30sec chair stands and in the Short Physical Performance Battery (6-22%). The 1 d/wk and 3 d/wk groups improved 400m walk times while the 2 d/wk PT group improved over controls in stair climbing power and stair climb time (4-7%). RPE was also significantly improved over controls. Author's Conclusion: In healthy older females incorporating low-intensity power training at 40% 1RM at 1,2,or 3 sessions/ week will improve the muscle strength and functional performance and training 2-3 d/wk may be required to improve both power and functional performance. You can trust the Physical Therapists at PEAK PERFORMANCE to do a thorough evaluation, to search for related but underlying contributing factors to kinetic chain dysfunction, and to design exercise progressions that both respect tissue healing and creatively use biomechanics principles to prevent symptoms and optimize carryover to your patients' functional goals. Call us at 218-0240 to discuss your patient's specific needs. Peak Performance is just minutes away from your patients in Penfield, Fairport, Pittsford, Brighton, Rochester, and, of course, East Rochester. We promise Individualized, hands-on and biomechanically appropriate Physical Therapy for your patients. No "one-size-fits-all" approaches. We WILL go the extra mile and "dig deeper" to discover underlying causes for injury risk and delayed recovery using the most advanced Evidence Based methods available and, we’re able to make unique adjustments to exercise prescriptions to speed the return to function and to minimize or prevent symptoms from interfering. No surprises. No hassles. Confident your patient is in the right place. COME VISIT US AT 161 E Commercial St Just 1 mile off 490 exit (585) 218-0240 www.PeakPTRochester.com